+++ #512 Subject: Re: Metalizing From: Rod Smith Subject: [bearhawk] Metalizing >I was talking to a friend the other day and he was talking about the >fabric and finish on his aircraft,he built a super cub from scratch and >the finish on the fabric is cracking all over the place.he has talked >to all the people that manufacture the finishes for over fabric and no >one can come up with a reason that it has cracked.this is one of the >reasons that I have been interested in metalizing the Bearhawk.thanks >for everyone giving me info on the advantages on fabric as opposed to >metal,now it makes sense to go with fabric if it will last 20 yrs + or >- . I live up in Vermont and the Wx.is somewhat extreme for time to >time,hopefully the acid rain we get won't bother to bad on the >finish.thanks,Sonny, plan # 234 You didn't say what he used for fabric or paint. Sounds like something wasn't compatable. If you spray fabric with an automotive polyurethane chances are the paint will crack as it doesn't have the flexibility that the fabric does. It is very important that whatever system you use, you stick with the manufactures recommended materials and proceedures. With exposure to acid rain you probably want to go with a polyurethane enamel topcoat as that has the best chemical resistance. Make sure you do a good job of corrosion resistance on the steel frame. With a plane parked outside, everytime the temperature drops through the dewpoint, water will collect on the tubing. I know from sad experience that eventually that will rust zinc chromate primed tubing. +++ #1965 From: Morrison, John Subject: [Bearhawk] Aluminum covering? Good day, Would anyone have insight on the issue of covering the Bearhawk with aluminum instead of fabric? Certainly thin aluminum sheeting could conform to the same shapes, and the Bearhawk doesn't seem to have any swooping curves along it's fuselage. What about weight per square foot and the resultant change in CofG? My concern is the airframe will be parked outdoors and flown off of seawater daily up here in Canada's Pacific coast. Fabric will take a terrible beating in these conditions. I know the wings are skinned with aluminum, therefore the tools and skills will be at hand. Thanks for any help. +++ #1967 From: budd davisson Subject: [Bearhawk] Re: Aluminum covering? This is a toughie, but if I were flying a steel tube fuselage off water, I think I'd like to be forced into looking at it from time to time and recovering a fuselage isn't all that hard. Razorback ought to stand up reasonably well. I'd guess bare aluminum would be about the same wieght as well-finished fabric, when all the support structure is figured in (you'll need formers to mount it and light stringers to keep it from canning too much. Metalizing isn't a totally bad idea but the inspection question still figures in. Here in paradise, we don't worry about moisture problems. We just have to worry about potentially nasty critters making a home in it. +++ #1970 Rod Smith Subject: [Bearhawk] Re: Aluminum Covering Well it would definitely be heavier. Somewhere I have seen the weight per square foot of fabric versus aluminum, probably in one of Russ's posts or maybe on his CD. Bob gave me the figure for just doing the flaps and ailerons in aluminum, I cant recall what it was, but it wasn't negligable. Then you would need a system to fasten the aluminum to the frame and that would add more weight. The modern day coatings and finishes are so good I would probably be more concerned with aluminum and salt water. See the recent comparison article in Kitplanes on fabrics and coating systems. You will definitely need good protection for the frame. Most primers dont provide a vapor barrier so you will want to top coat the frame with polyurethane or something similar, or just have it powdercoated. I just saw a PA-12 last week with an aluminum fuselage. I thought it looked terrible compared to fabric. The lines just looked all wrong. But thats just my opinion. +++ #1972 Rod Smith Subject: [Bearhawk] Re: Aluminum Covering > Thanks for the tip, I'm not convinced aluminum is the way to go > either. Isn't the wing on the Bearhawk aluminum covered? Is it just > the control surfaces that are fabric? I may be way off line... Thats correct, the wing with the exception of flaps and ailerons is aluminum skinned. +++ #1977 Russ Erb Subject: [Bearhawk] Re: Aluminum Covering > Thanks for the tip, I'm not convinced aluminum is the way to go > either. Isn't the wing on the Bearhawk aluminum covered? Is it just > the control surfaces that are fabric? I may be way off line... The wing is covered in aluminum because the skin is part of the structure. Primarily, the skin plus spars forms the wing box for torsional strength. Amongst other things, if the wing were fabric covered (which carries no/little load), it would need 2 struts on each wing (see Cub, Champ, etc) for torsional rigidity. Properly done (i.e. follow the directions and don't think you know more than the guy who wrote them), today's fabric covering systems are incredibly strong and durable. As budd said, you'll want to pull it off to inspect the structure before it wears out. Following are previous discussions of aluminizing straight from the CD (if you don't have one, you need one, and I can get other people to say that who don't get any money out of it). ************************************** November 1999 I have been sitting here reading the talk of Tig welding,the different powerplants,and the wiring.so it lead me to thinking down the road and I was wondering has anyone thought about metalizing a Bearhawk.I don't have a hanger to store it in,and I havn't come up with any push-button and there is your airplane shelter,so the metal seems to make sense today.since I am not in a hurry to get the airplane done because on minimal extra time.any thoughts,Sonny With all the stories of old fabric(cotton) and its deterioration there has come into existance the belief that fabric covered planes don't last when stored outside. If you keep the coating clean, waxed and repaired if any cracks develop in the coating, the plane will last 20 years before it needs recovering. The ONLY thing that causes deterioration in polyesther fabric is exposure to UV light. If the coatings are cared for the fabric will be sound forever. If along the way you rejuvenate (dope) or re-color coat when wear starts to show the fabric will last longer than you want to go between strip down inspections of the tubing. Then again, mounting tabs with nut plates would allow for relatively easy covering with aluminum--wouldn't last any longer, but do-able. Bruce A. Frank Well, let me qualify my statement by saying that "I'm no expert". But If you beleave the Poly Fiber folks (and probably other fabric producers), a properly painted fabric finish will last as long as a metal finish. Who knows. A lot depends on your use. If you use if in a rough and tumble environment with possible scapes and such, fabric has some advantage. It can be patched and painted easily (depending on the paint used). And if in a bind, good old 100 MPH tape (duct tape) will get you home. Tim Anderson Aircraft are all built for a specific use. I think the Bearhawk fits a market for intense bush flying, along with a high opps factor (opps= not a good landing) survival. The tube and fabric system allows for a very strong cockpit area yet keeping the weight off. Tom Yeomans I was talking to a friend the other day and he was talking about the fabric and finish on his aircraft,he built a super cub from scratch and the finish on the fabric is cracking all over the place.he has talked to all the people that manufacture the finishes for over fabric and no one can come up with a reason that it has cracked.this is one of the reasons that I have been interested in metalizing the Bearhawk.thanks for everyone giving me info on the advantages on fabric as opposed to metal,now it makes sense to go with fabric if it will last 20 yrs + or - . I live up in Vermont and the Wx.is somewhat extreme for time to time,hopefully the acid rain we get won't bother to bad on the finish.thanks,Sonny, plan # 234 You didn't say what he used for fabric or paint. Sounds like something wasn't compatable. If you spray fabric with an automotive polyurethane chances are the paint will crack as it doesn't have the flexibility that the fabric does. It is very important that whatever system you use, you stick with the manufactures recommended materials and proceedures. With exposure to acid rain you probably want to go with a polyurethane enamel topcoat as that has the best chemical resistance. Make sure you do a good job of corrosion resistance on the steel frame. With a plane parked outside, everytime the temperature drops through the dewpoint, water will collect on the tubing. I know from sad experience that eventually that will rust zinc chromate primed tubing. Rod Smith #246 Wasilla, AK thanks for the info on fabric finish cracking,I havn't see my friend to ask what he used for a finish or fabric,but will.after he spent all of his time building an aircraft from scratch,he had no plans,he just went out and took the measurements and went back and built the part.A hard way to do things,but you want what you want.just A thought on levelers on the work tables,I used the levelers off of old washing machines,go to the dump,there are lots of them around. Sonny,plan # 234 ************************ January 1997 P.S. Bob has the plans-built wings on the prototype plane.....my building partner reports that it flys great. I hope to fly it myself. We were going to metal skin the alieron and flaps, but he said the fabric covered ones are very light and well balanced. Mmmmm. John Lenhardt Be very careful doing this--run it by Bob and by all means make sure they are balanced. Typically metal skined are heavier, and we're not talking ME-262 speeds in our beloved homebuilt. Changing the design of control surfaces can invite flutter problems if not done right, especially on ailerons. Hate to be a wet blanket, but flutter is something that always causes concerns for us flight test folks. I'd be curious why you want to do this--is it merely for looks? I'm guessing that they will be heavier. It's not like you'll get out of working with fabric--we've got the whole fuselage and tail to do. Of course, in the end, it's up to each builder what he/she wants to do... Russ My bird, unfortuneately, will have to live outside. The metal surfaces would stand up better and I would only have to cover the fuselage. However, we are rethinking this. We were designing they with Bob's help. I'm not much of a test pilot. We are friends with Bob and he is the also the technical advisor for the EAA chapter. What a great local resource! John Lenhardt +++ #1980 From: Bruce A. Frank Subject: [Bearhawk] Re: Aluminum covering? Fabric is not inferior in its durability. Aluminum in salt water requires some very specific and tedious preparations to allow it to survive long term in a salt water environment. With todays fabric coatings(urethane being one of the most durable) if application specifications are followed to protect the underlaying fabric and maintain the coatings, outdoor storage will still see 20+ years of life(some exceed 30). Since we are no longer using cotton or linen, the salt water itself has no deleterious effect on the fabric or the coatings. The more worrisome problem is the tube fuselage itself. Eventually floats will go on my project which is the reason that I intend to have mine powder coated. I have seen some tube fuselage Pipers that saw 30 years of sea plane life with no corrosion of the lower longerons. The factory protection method was to wrap the lower longerons (after standard painting) with a tar-like impregnated tape. The fuselage I helped to restore had no internal protection (no linseed or other oil type) but there was absolutely no internal (or external) corrosion of the lower longerons. +++ #5119 From: Rod Smith rsmith@a... Subject: Polyfiber Class I spent a very enjoyable weekend attending a Polyfiber class in Anchorage. Jon Goldenbaum, his wife and a couple other instructors brought their road show to Anchorage. The class was two full 8 hour days and for the most part is hands on. They bring four DC 3 ailerons with them that you cover from start through finish coat. At 12 1/2 foot by 35" chord they make great simulated wings. Having previously covered a fuselage and tail feathers I wasn't a total novice, but left feeling like I had gotten more than my $225 worth. The polyfiber book and video are very detailed but there is nothing like working with the people that make the stuff and instructors who recover for a living. Learned lots of very useful tricks that you probably wouldn't pick up on your own. Learned a few mistakes I had previously made, fortunately of the cosmetic variety, not airworthiness issues. Lots of discussion about the various processes and the dangers of listening to the airport know-it-alls instead of religiously following the Polyfiber or Ceconite manuals. If you do not have covering experience you would really benefit from this class and like myself I think most people with some experience would also benefit greatly. Del I met Troy and Pat from Cordova, they were very complimentary on your workmanship. +++ #5178 From: Russ Erb Subject: Erbman's Updated Color Scheme I invite you all to go to my Bearhawk page at http://www.eaa1000.av.org/pix/erbpix/erbpix.htm and check out the drawings of my updated color scheme. Most of it is the same, but the nose treatment is different and the tail is slightly changed. I contracted the services of Mike Machat (http://www.mikemachat.com) (my favorite aviation artist-check out his web site) for help in redesigning the nose section. On his web site you'll see that he offers a service to design your color scheme for your airplane. He has said to me "yes, it would be fun to see all the different design approaches people might take with Bearhawk color schemes. It's a very neat looking airplane." Obviously he has good taste. His prices are very reasonable when you consider that people are going to react to your color scheme far more than anything else. Be sure to check out the perspective drawing I did based on the photo from the Oct 95 Sport Av article. It turned out most cool! I've included the new drawings in a Powerpoint 4.0 file for downloading. Note that for the N-number to display correctly you'll need to install the bduku___.ttf font file from the files section at our group web site. I've also included a picture of the airplane that originally inspired me. Enjoy, and feel free to download the files and redraw your own ideas on them. +++ #5198 From: "Tim Anderson" Subject: Re: [Bearhawk] Re: Erbman's Updated Color Scheme Yellow makes for a nice visable target in the air..I painted my kitfox Piper cub yellow. One interesting point I learned about yellow was that it takes a lot more paint, then other colors, to cover the "silver" (alum) light-blocking coating. When I re-painted my fuselage (post crash), I started with a coat of white (much much cheaper), then finished with yellow. Worked much better. That was with poly fiber poly tone. Not sure if poly fiber aerothane was the same covering properties. Aerothane is much glossier but harder to patch. +++ #5199 From: Tim Subject: Re: Erbman's Updated Color Scheme..Tough Paint Thought I would mention that ' Endura' paints out of Edmonton, Alberta have two nice shades of Yellow.......RCAF and HARVARD yellow... Endura has have a flex agent for fabric covered aircraft application. Quite a few a/c up here, be it fabric or Aluminum have Endura paints jobs. They ship to the USA and supply the required VOC list for California (volatile organic compounds)....This paint is TOUGH and was originally designed for the wear/tear on Oil Rigs...Dean has painted his Montana Coyote / Mountain Eagle with it........COST: Part A $104.33 Part B 113.00 Cdn Some savings there for the strong U.S. Dollar. Endura 1-800-661-9930 +++ #5203 From: Russ Erb Subject: RE: [Bearhawk] Re: Erbman's Updated Color Scheme I painted a yellow pedal plane years ago. Yellow paint is rather transparent. The approved solution for yellow, red, and most other paints is to start with a white base coat to reflect the light back out. I saw the difference when trying to apply touch up paint without the white undercoat--big difference! +++ #5204 From: Rod Smith rsmith@a... Subject: Yellow Paint - Visibility This was talked about in the Polyfiber class I just took. In the latest manual it is highly recommended to undercoat red or yellow with a coat of white paint, just thick enough to cover, for the reasons Russ mentioned. Guess this would apply to orange also. Believe it or not they also suggested undercoating black with white. Something about it would have a much better luster. I painted my Maule Lemon Yellow with AN Blue trim. It took four or five coats of Yellow over the silver, wont make that mistake again. Type of paint doesn't matter. For visibility yellow is real hard to beat. The best is probably international orange if you can stand it. Had a Schweitzer 1-26 in solid orange in a glider club I was in. You always knew where it was. I dont think darker reds like Bob's planes stand out at all. When Bob flew into Palmer I saw a plane approaching, looked like a Bearhawk but couldn't tell it was red until it got quite close, blended in well with the mountain in the background. +++ #5214 From: "Tim Anderson" Subject: Re: [Bearhawk] Yellow Paint - Visibility Another drawback to maroon is that it may fade...something to do with maroon pigment...it always seems to fade with time. +++ #5264 From: Russ and Penny Erb Subject: RE: [Bearhawk] Plans, parts lists, construction tips, etc. I'll just address a couple of things. According to Poly-Fiber, with today's polyester fabrics (not cotton) and properly applied coatings (including a physical UV block), you can leave a fabric covered airplane outside for 20 years with no problems. Fabric really has a lot of benefits that seem to have been forgotten over the years. I still think the RV crowd with their monocoque fuselage has a lot more work in store than we do. +++ [ a rec.av.homebuilt exchange ] From: Shelly Newsgroups: rec.aviation.homebuilt Subject: fabric covering The area that always seems to give me trouble when covering is the fin as it extends from the fuselage. I've tried making a fiberglass lay-up to glue to. I've tried stitching. I've tried pre shrinking. Nothing I do seems to really look great. If any of you have any new or different technics, I'd like to hear them. From: Carl weemoose@aol.comjunkbloc (Wee Moose) Newsgroups: rec.aviation.homebuilt Subject: Re: fabric covering > The area that always seems to give me trouble when covering is > the fin as it extends from the fuselage. Its been some time since I have covered a full-scale plane -- but the most important thing is to get the covering tacked on the framework with as few wrinkles as possible. Were the plane a model, I would cover in smaller sections, overlapping as I went. If help is handy or if you have some small clamps that you can weigh down to pull fabric smooth after you have attached it to one edge. I don't remember how long Poly-tac takes to dry so the weight idea might be better than having someone waiting for glue to dry. From: "Tom Cummings" Newsgroups: rec.aviation.homebuilt Subject: Re: fabric covering If I correctly remember reading something once, an aircraft such as a Piper Cub, that has a covered area between the rear of the fuselage and the rudder, giving the appearance of a gradual blended fairing, that portion of the covering operation requires sewn seams to obtain the desired results. In effect, covering in smaller sections, as Carl mentioned. The problem is that there are no underlying supports to attach the fabric in smaller sections- thus the sewn seams. Several pieces of fabric are straight pinned together before cementing to the structure - pinned to the turtle deck fabric part. Then the pieces are sewn together, put back on the framework, and then cemented. One is kinda making a presewn half-sock shaped envelope. Sometimes the fabric is handsewn while the fabric is on the fuselage, after being pinned together, pulling and stretching as necessary as you go. then tack cemented. From: Gary Newsgroups: rec.aviation.homebuilt Subject: Re: fabric covering Shelly, I have been covering planes for about 20 years. I do Cubs, Scouts and Schweizer gliders a lot. We will be doing flight controls on a Thrush sprayplane. I also teach covering at an A&P school part time. We are currently restoring a Piper PA-11 and a 1936 Stinson SR-7 Gullwing. WE do dope method sometimes, at customers request but I prefer the PolyFiber menthod the most. I would like to know what kind of plane you are covering. But if it is a Cub or Citabria type there is one simple method of covering the fuselage back and fin area. First I cover the bottom of the fuselage gluing the fabric to the lower longerons. Then I take two 72" wide by the length of the fuselage, sections of fabric and pin them together along one edge from end to end. Then drape them over the fuselage from the top of the cabin to the tailpost. Make sure you leave a bit of overhang beyond these structural ends to wrap and glue as required. Now, you are going to have a section above the fuselage that spans the crotch of the fuse to fin area. With a "PENCIL" ( if a #2 pencil is the most popular pencil, why is it still #2) and an assitant on the opposite side from you, mark where the two fabric layers would meet down the spine of the fuselage from the top of the cabin, down the back to the junction of the fin to fuselage and up the fin. Using dress making pins, pin the two layers together along this line. Do Not worry about the wrinkles you have at the lower fin leading edge area in the transition zone. Recheck, that with the pins in place, you have enough fabric extending beyond the periferral edges of the structure where you will be gluing. Make sure you have ample for triming. Now remove the fabric draped across the fuselage and take it to a good household dressmakers sewing machine. Load in a #10 thread on the bobin and sew up the area where the pins are along the mark you made. The preferred seam is the French Fell seem but if you cannot do that, (it is touch) then do a modified fell seam. All this information and illustration is in the PolyFiber manual available if you contact them at www.info@polyfiber.com. Once the seam is sewen inplace drape it back on the structure. Center the seam on the spine of the aircraft and glue it along the bottom stringers and tail post. The seam should run up the center of the fin leading edge, Keep in mind that some aircraft have the lower end of the fin offset a bit so it might not line up with the leading edge until you are a ways up the tube. Take out some of the wrinkles as you glue, but you wont get them all. DONT WORRY...the magic will come later when you iron it to shrink. Note I said IRON!!! This is key. Use a calibrated iron ( calibrate it with a candy thermometer on the base) and mark the temperature control for settings of 225, 250 and 350 degr F. Once your glue is dry ( it can be in 15 minutes) smooth out the glue with a setting of 225DegF Poly Tac glue softens a bit at this heat and the pressure of the iron will smooth the fabric and help adhesion. Then reset the iron to 250 deg F and iron over the whole surface of the fabric avoiding the wrinkled area at the crotch at the lower end of the fin Leading Edge. Do it last. You will be amazed as the majority of the wrinkles will disappear before the iron gets to them. There still may be some small ones left after a good ironing. Contact all the fabric surfaces with the iron at this setting. NOW, are you finishing with dope? If so, you are ready to apply the first coats in accordance with that process. If you are using PolyFiber system, reset the iron to 350 deg F and iron it all again, and as before, avoid the crotch area intil last and then iron it till you see the magic worked and took out all the wrinkles. It has worked time and time again for us and I know it will work for you too. If you run into any problems, Poly fiber are great at solving your problems but feel free to contact me again. We do this for a living in Western Canada. Good luck. From: Shelly Newsgroups: rec.aviation.homebuilt Subject: Re: fabric covering Thanks Gary, Your technique is a good one and I have no problems with the general fuselage covering. The area that always confounds me is that "tent" that always seems to form between the two upper longerons (as they converge toward the tailpost under the leading edge of the fin) and the first horizontal rib of the fin which is about 10 inches up from the fuselage. So, I always end up with a very wide covered empty space between those two longerons and the leading edge of the fin and the first rib of the fin. I imagine the area to be very dirty aerodynamically. In my mind, what I call a tent, you would call a crotch. As I read your message, your secret is to shrink every thing else first and save that area till last. I can't imagine how or why that would work to narrow the tent, but I am certainly willing to try. I'm thinking of shaping a small piece of curved aluminum tubing and attaching it to the leading edge where it meets the spine so that it will be slightly more streamlined and perhaps help to narrow the "tent". By the way, do you stitch to the fin ribs? Yes, it is a "super cub" type and I am planning to use Superflight polyurethane. This is a very hard area to define and describe so that we are talking about the same spot. +++ #6087 From: "Bruce A. Frank" Subject: Re: [Bearhawk] Re: Fabric and the O to O >Should we interpret this to mean that you are opposed to punch >testing or any other testing of old polyester fabric because it >won't fail anyway? Cotton and linen failed from bacteria action (mold and mildew) and UV exposure. Polyester fails only from UV exposure(and temperatures that will melt plastic). A punch test on the old "natural" fibers gave a reasonable idea of the overall deterioration. Poly breaks down only when there is a failure of the coatings. Poly is much stronger than the natural fibers to begin with. I believe Budd's reference with "fabric doesn't fail" was that fabric is up to the strength required for the operating parameters of the plane. The plane's performance does not exceed the capability of the fabric. There is no basis for doubts of the ability of fabric to survive the operation of the aircraft. Fabric is not some new wild idea (like putting automobile engines in an airplane) it has been around for nearly a century and all of its idiosyncrasies are noted, documented, and allowances made. +++ #6089 From: "Bruce A. Frank" Subject: [Bearhawk] Aluminum wings (was: Fabric and the O to O) I should have added one last point, fabric coverings are NOT inferior to aluminum skins. Now that I have said that, I have a question about the Bearhawk wings. Other than the single strut design, what advantages do the aluminum wings have over fabric covered wings using the same airfoil? Bruce A. Frank +++ #7069 Date: Mon, 6 Aug 2001 09:45:39 -0500 From: "Montee, Dan L." dlmontee@ Subject: HVLP Turbine systems I'm about to purchase a HVLP spray system the works off it's own turbine to paint BH parts as well as other projects. I like the portability, (not tied to my compressor) and the high transfer efficentency. The system I'm going to purchase is the Apollospray. That's the one demo'd at AirVenture. Does anyone in the group have experience with HVLP turbines in general or Apollospray specifically? I'd appreciate hearing your opinion. Dan Montee # 415 Temp 90+, heat index 105, dew point 78, Wisconsin is not suppose to be like this!!!!!!!!!!! I had to put in a window airconditioner in my shop this weekend!!!!!!! +++ #7072 Date: Mon, 6 Aug 2001 08:57:05 -0800 From: "Float-By Shooter" del@ Subject: Re: HVLP Turbine systems > I'm about to purchase a HVLP spray system the works off it's > own turbine to paint BH parts as well as other projects. I just finished painting my pickup truck with an Accuspray HVLP turbine system which my dad bought a few years ago for his MG project and for painting our fleet of freight trucks. The main reason he bought it was to get away from painting with the regular air system, to eliminate oil and water contamination and of course for the paint savings due to less overspray. The shop is less than 100 yards from the ocean, and blisters have been a reoccurring problem painting here with a regular gun (years ago an autobody shop was part of the business). The HVLP seems to be doing its job, since neither of the 2 airplanes or the other truck (too early to tell with the one I just finished) that have been painted with it have developed water blisters over the course of several years. This was my first experience with spray equipment other than rattle cans, and after learning a few of the quirks of the equipment it seems to have worked just fine for my purpose. The finish on my truck isn't going to win any awards but it looks fine and is more than good enough for a work truck, though I am sure with an experienced operator the equipment is capable of much better. My biggest problem was inability to keep a wet coat going, since due to the hot air produced by the turbine, the paint seemed to be half dried by the time it hit the panel. If I layed down enough paint to get it to flow together well, it often wound up too thick and took longer to fully cure. This was with plain old acrylic enamel, which I figured was simple enough for a novice painter to use. I'm sure there are better paint systems to use with this equipment if I had wanted to. The HVLP saved me a lot of hassle since I don't have a dedicated paint shop to work in; I did all my bodywork in our warehouse in between times when it was full of freight. The low overspray meant that I didn't have to go crazy covering everything up or building a paint booth. It also saved a lot of paint. I bought a couple of gallons of my color choice and never even opened the second one, I did the entire fullsize pickup with just under a gallon, so I have an unopened can of fresh paint if I ever have to repair damage to it. Hopefully I'll never have to open it, since I'm really glad to be done with autobody work at this time. Del Rawlins-- +++ #7084 Date: Mon, 06 Aug 2001 21:21:59 -0400 From: Shelly shell@ Subject: Re: HVLP Turbine systems Let me put in a good word for the Accuspray! Fred and I painted our last two projects, a Hatz and the Mountain Goat with one of their units I bought about 8 years ago. It works well and stands the test of time- what more can I say. It's easy to clean and keep clean. Have a look at our article in the recent "Experimenter" on building and using a paint booth within our workshop. Shelly +++ #7086 Date: Tue, 7 Aug 2001 09:41:28 EDT From: dewcraft1@ Subject: HVLP Sprayers You can get excellent results with either of the major brands of HVLP sprayers. I use the reducers designed for higher temps, winter or summer, like Poly Fiber RR8500 Reducer (slower drying), with the appropriate Poly Fiber products, to accommodate the higher temps at the gun produced by turbine sprayers. Works every time and can give you show stopping results. Painting is an art, not a science, i.e, practice/ experience will improve your results but, bottom line, the equipment will not be the limiting factor in your achieving quality work. Jim #440 >>> 2mar02 #7686-9153 +++ #8456 From: Russ and Penny Erb Subject: Attaching Tail Fuselage Access Panels For Mike or anyone else who can answer: On the prototypes there are several access panels around the tail for access to the elevator and trim horns, the front stab adjustment, etc. The data plate is even attached to one of the access plates. Since these panels are located in the fabric areas, the question: What is the backup ring (that the access panel screws into) attached to? Is it just attached to the fabric or is it attached to the underlying structure? BTW, I would not recommend attaching the data plate to an access panel. I'm not sure how The Bob's FSDO interprets 14 CFR 45.11, but as I read 45.11 (or the following excerpt from AC 20-27E), the data plate needs to be attached to a non-removable part of the fuselage. See the part that says "it will not be...removed during normal service". You can argue if removing an access panel (which you would probably do during the annual inspection) constitutes "normal service" but my experience has been that when dealing with the FAA, leave no question in the interpretation. "a. The aircraft must be identified by means of a fireproof identification plate that is etched, stamped, engraved, or marked by some other approved fireproof marking. The term "fireproof" is defined in part 1 as "has the capacity to withstand the heat associated with fire at least as well as steel in dimensions appropriate for the purpose for which they are used." For example, should an aircraft constructed of wood and fabric be destroyed by fire, the identification plate should remain intact. The identification plate must be secured in such a manner that it will not be defaced or removed during normal service, or lost or destroyed in an accident. Attachment by riveting or bonding is acceptable. Section 45.11 requires the identification plate to be located on the exterior either adjacent to and aft of the rear-most entrance door or on the fuselage near the tail surfaces, and must be legible to a person standing on the ground." Russ Erb +++ #8462 From: pfflyerz@c... Subject: Re: Attaching Tail Fuselage Access Panels > What is the backup ring (that the access panel screws into) > attached to? Is it just attached to the fabric or is it > attached to the underlying structure? I wondered about that as well, but they covered the topic nicely in the Sportair covering class. The access panel is created just like a giant inspection ring circle. Make the cut out from aluminum and attach nut plates or Dzues receptacles to it then Poly Tack the ring to the inside of the fabric. Finish it off just like the normal inspection holes then cut out the fabric for access. They said you can make an inspection panel any size or shape this way. Who said homebuilding was cheap? I bought my engine and all my instruments this year and have now just purchased a new Hartzell 3-blade prop. Thank God there is not much left to buy. Pat Fagan #232 Pearblossom CA +++ #8485 From: Ken Beanlands Subject: Re: [Bearhawk] Attaching Tail Fuselage Access Panels > What is the backup ring (that the access panel screws into) > attached to? Another tip is to use plexi as your inspection plate especially if the plate covers control horns like the elevator or aileron controls. The Christavia's elevator horn is buried in teh tail of the plane. A plexi inspection plate allows for a good look on teh pre-flight. Ken Beanlands B.Eng (Aerospace) +++ #8583 From: "erbman89b" Subject: Colors... > Please tell me that you plan to paint (or have painted) your > aircraft some other color than maroon. I think 4 Maroon > Bearhawks are enough. > > Later - Mike Hey Mike: I've had drawings out on the web for a few years now showing that I plan to paint #164 in yellow and red. All the more amazing when you consider I went to grad school at Texas A&M, which of course has school colors of maroon and white. Russ Erb +++ #8584 From: "Bob Marek" Subject: Aircraft color My BH is not painted maroon its Santa Fe Red and Daytona White very beautiful colors. You got all that snow schoveled yet had to get the lawn mower ready here the grass is growing. Its great flying around on wheels hope to get through this winter without skis. With very little snow on the frozen lakes around here they make excellent landing strips. Great way to go ice fishing. BH flying great almost 70hrs on the tack. Bob Marek 019 +++ #8587 From: "teyeomans" Subject: color. I have the base fabric on an off white. I plan on the first phase of flite to be not painted. I'm sure I will be doing some mods to the engine and who knows what that will be or lead to.. As with the interior, If I have to look at it myself only for 40 hrs it might as well be in the air with nothing. Tom yeomans +++ #8883 From: "Bruce A. Frank" Subject: RE: Bearhawk Curious > By the way...mine's going to be arctic white with jade green > stripes and gold pinstripes. Now that will really be visible to search and rescue in AK! Why not go for full camo! (Unfortunately my son thinks full camo is the absolute best idea ever...I favor Piper Cub yellow) 8^) Bruce A. Frank +++ #8884 From: Ken Beanlands Subject: RE: Bearhawk Curious At one point I tried to come up with a colour that would be visible in all terains AND seasons. I could not come up with such a colour. The problem is that even International orange, Cub yellow, etc can become "cammo" colours in the fall of the year. Have you ever flown over the Gatineaus in the fall of the year. There's every colour you can imagine down there. About the only colours that I could think of is some kind of hot lime green or purple. I'm sorry, but that's just too FUGLY ;-) I decided to go with Bayou Blue and a cream colour on the Christavia. I decided on a classic scheme of the fuselage in blue and the wings and tail in cream with some trim of the opposite colour on each. Ken Beanlands B.Eng (Aerospace) +++ #8888 From: "Bruce A. Frank" Subject: RE: Bearhawk Curious Anyone ever done an evaluation of black and white checkerboard (the old barnstormers favorite decoration) visibility from the air during low level search flights? I really lean towards tail and outboard halves of the wings in checkerboard...but probably more from a "oldtime" look rather than downed visibility. Bruce A. Frank +++ #8915 From: "Chris Vuxton" Subject: Bearhawk Colors 25 years ago there was a wildman living in New Hampshire that made camping equipment, tents, cloths, that sort of stuff. The fact that all of his catalog models were naked is besides the point. He was a Lockheed engineer and had some very radical ideas for the time, like a totally sealed tent. Better to wipe off some of the breath condensation inside and stay warmer. Anyway, his catalogs were always filled with interesting info (this is where color comes in) and one time he was talking about color for tents in snow country. You know what bright color goes black fastest as light fades? Day Glow orange. The AF painted the tips of airplanes DG orange when it wsa too bright to see the strobes. As it got dark it didn't matter what color the orange looked. He maintained a yellow tent with green ends would do best. I'm going for Artic White with bright yellow (a color Maggie dislikes) and Navy (a color she likes and hopefully balances the dislike of the yellow)trim. I don't plan on going down in the snow and will try to fly from dark spot to dark spot if I come upon snow (not likely here in VA). Chris +++ #9057 From: Benton Holzwarth Subject: Coloring and visibility > Anyone ever done an evaluation of black and white checkerboard > (the old barnstormers favorite decoration) visibility from the > air during low level search flights? I recall a camoflage design that used large irregular blocks of stark black and white color to hide ships. Anything that breaks up the outline acts as 'camo'. One of the local tower guys came to a chapter meeting a while back. Someone asked what color was easiest for them to see (in the air). Reply, without a moments hesitation... "Red." Benton 23feb02 +++ #9058 From: "Bruce A. Frank" Subject: Re: Coloring and visibility Then maybe red and white checkerboard? Bruce A. Frank >>> 4sep02 #9154-11297 +++ #10492 From: Russ and Penny Erb Subject: Airplane Noises! Well, I finally did it. I finally let myself sit in the cockpit of #164 and make airplane noises. ... 4. As I pulled up into a loop I naturally looked up and back for the horizon just like I do in the glider. Then I realized that I would be looking through two layers of opaque fabric. If it is possible to loop a Bearhawk, it will either need a skylight back to the rear spar (which I'm not planning to do) or a different technique than I'm used to. Most people talk about the view down over the nose (which seems will be very good). Few talk about the field of view up since it doesn't matter that much. Even so, it doesn't look like much without leaning forward, but I don't think it will be a problem. +++ #10847 From: "bcschutt" Subject: welding and covering (1)... 2) when covering the flaps and ailerons---glueing/bonding the fabric to the structure----how tight to make the fabric-that is before shrinking, very tight, just up snug, bearly smooth,loose and saggy? end to end and also front to back? Thanks for any help you can give me +++ #10849 From: Ken Beanlands Subject: Re: welding and covering What I did for covering the Christavia was to lay the fabric on teh surface. Make sure that the gluing surfaces were smooth (no wrinkles) and whereever that put the loose fabric is where it was glued. The fabric has a lot of shrinking capacity so you should be able to get adequate tension even with loose-saggy. The lengthwise force over an aileron or flap shouldn't be too great. However, on a full wing panel, the force generated by shrinking the 30' of fabric can become quite large. Some manufacturers suggest using a lower temp to aviod distorting the structure, especially on UltraLights. Hope this helps +++ #10850 From: "Bruce A. Frank" Subject: Re: welding and covering One of the most useful things I have bought during the building process was the Stitts (now Poly Fiber) video tape on fabric covering and coating. The process is the same whether applying the poly-fiber system or dope. The fabric is the same type of polyester if Ceconite or Poly Fiber and responds to the same shrinking temperatures. The tape makes it fairly clear, nothing beats a picture, as to how taught the fabric should be before the shrinking process. BTW, the tape is described at http://www.polyfiber.com/stits/ Lot of good info at that site (even though I'll probably be using dope). +++ #10855 From: Russ and Penny Erb Subject: RE: welding and covering > 2) when covering the flaps and ailerons---glueing/bonding the fabric > to the structure----how tight to make the fabric? 2. Make the fabric snug. That is, pull out the wrinkles, then let go. As it lays there flat is tight enough initially. +++ #10859 From: "Daniel Fox" Subject: Re: welding and covering I took the SportAir workshop on fabric and covering (when it was Ron Alexander's baby, not the current EAA series). It was taught by Lynn Zaro, and it was just great! Definitely worth the weekend, the $240+/-, and the travel. I only wish that they were still giving them at the Frederick MD location; now I have to go to Pittsburgh (5-6 hr). +++ #10866 From: Jim Ash Subject: Fabric Re: welding and covering > One of the most useful things I have bought during the building > process was the Stitts (now Poly Fiber) video tape on fabric covering Akin to the video, I bought a 'play with fabric covering' kit from Aircraft Spruce maybe 5 years ago. The kit put together by the Polyfiber people. It contained a how-to book, a wooden frame with a 'rib', enough fabric to cover it several times over, cord (flat, I think) and a needle, straight tape (no bias tape), and inspection port ring, and all the goop and brushes to make it all happen, up to and including the silver coat. They also give you the thermometer used to calibrate your iron. I think the kit was about $30. I learned a ton of cool stuff about fabric covering, and stitching in a couple weekend afternoons. Highly recommended, even if you don't plan on using Polyfiber. >>> 20may03 #11298-18250 +++ #12118 From: "Bruce A. Frank" Subject: RE: Re: color scheme I talked to a sign maker down the street about vinyl applique to create such a bottom of the wing pattern. If he cut them on his computer controlled machine they would cost about $2.00 per square. If I bought the material and cut them myself they would run about 30 cents each. I have done vinyl applique before and it is about 100 times easier than masking and shooting paint. At the cost of color coatings for fabric these days vinyl appliques would cost much less. With no maintenance such vinyl has a outdoor life of about 10 years (according to the sign maker). With washing, waxing and hangaring I'd expect twice that. Poly Fiber (Stits) is a vinyl process, unless the glue gives up seems the appliques could last the life of the fabric coating. Bruce A. Frank +++ #12119 From: Budd Davisson Subject: Re: Re: color scheme As one who has painted dozens of flamed paint jobs, do the masking the easy way. Use 1/8" tape to outline and build with 1/4 or 3/4 from there. Mask it in positive, not negative, meaning the smallest amount of paint on the airplane (maybe a stripe) goes down first and you just mask out something the shape you want it to be, rather than leaving a space the shape you want. Makes it easier to keep from making a mistake. Also, and I don't know what they are doing these days, but, after putting the trim tape down, I'd dust a coat of clear on to seal it, that way when it's pull off, there is no color paint bleed under. bd +++ #12123 From: Budd Davisson Subject: Re: Re: color scheme The striping, diamonds, etc, on my Pitts was vinyl stick-ons and you couldn't tell the difference. Who ever put it on was a master. The only way we knew it was vinyl was when we refinished the airplane after 12 years. bd +++ #12124 From: "John" Subject: Re: color scheme We just finished a T-CUB using the same paint scheme(white/red). We shot everything in white, then taped off for the red. We did it the way Budd suggests, using 1/8" fine line tape for all the scalloped curves but 1/4" fine line tape for all the straight lines. We then applied 3/4" masking tape overlapping those. (YES it did take a LOT of tape!) We also shot all the tape edges with clear to seal them before we shot the color. I considered using vinyl squares under the wings as it was a lot of taping, but decided that they would probably be a real pain to apply over all of the rib stitching and fabric bowing between the ribs. Of course the Bearhawk has metal wings so that would not be an issue. There were a few details that I will do differently next time, but overall it went very well and looks great. BTW, the taping goes a LOT faster with 2 people.... Hopefully, the T-CUB will make its first flight tommorrow. Yippie! I'll take a couple of pictures.... John Kozak, #511 +++ #13549 From: Budd Davisson Subject: Re: Piggot project visit / photos online > Where does the razorback fiberglass process fit in to this > discussion of glass coverings? Razorback is still a fabric covering process only slightly different from any of the Dacrons. The biggest difference is that it's a glass cloth and supposedly lasts forever, which some think is good, but most of us don't. You want to see the inside of a rag and tube airplane from time to time and Ceconite lasts long enough. To get a good finish on Razorback without a huge amount of its coarse weave showing through takes a lot of build-up and you have to work at it to get good paint adhesion because it's a very mechanical lock with no chemical adhesion. bd +++ #15629 From: Budd Davisson Subject: Re: The Case for Electrical... > If anyone was serious about performance, they go no electrics, > polish the wings and finish the fabric through silver... > > What do you mean by "finish the fabric through silver?" What Budd said about finishing through silver means stop with the silver UV protection coats and don't put any color on it. One of the biggest mistakes people make is putting too much paint on an airplane. Often they think they should hide the weave of the fabric and that can more than double the weight of the paint. On an airplane the size of the BH it would be really easy to increase the empty weight by 80-100 pounds with the finish. As I mentioned last month, when we weighed my two-place Pitts after recovering it last August, we found we'd knocked over 70 pounds off the airplane. It now weighs in over 80 pounds UNDER the factory spec empty weight and you can tell it in the way it flies. One thing about modern, high-solid color coats however: you don't need much of it, so even though it's heavy, you don't use much so it comes out much lighter. bd +++ #15843 From: "Dave Roberts" Subject: Windows and skylights I assume most builders are using lexan of something similar on the skylights and windows. My question would be, 1/16" or 1/8"? Or both? 1/8" on skylight, 1/16 on side windows? Thanks, Dave Roberts +++ #15844 From: "Bruce A. Frank" Subject: Re: Windows and skylights The thicker the more sound attenuation. Make sure the skylight has UV inhibitors. Straight Lexan does not last long when exposed to sunlight without UV protection. A splash of gasoline can cause crazing and cracking on unprotected Lexan (polycarbonate). Bruce A. Frank +++ #15895 From: "Mark Conover" Subject: Kinder Gentler Skylights After sitting in Gordon and Ken Wardstrom's Bearhawk this afternoon, I noticed that my preferred skylight configuration would work very well. Having grown up in a hot place (Texas), I'd just as soon not do any more baking in the sun. So I'm not too interested in a large skylight. But, I do want additional visibility in turns, or in situations conducive to the classic Piper//Cessna convergence accident. I like the idea of dual elongated skylights that parallel the centerline of the aircraft. Take a look at this to see what I'm talking about (photo found on aerofiles.com): http://www.conotech.com/public/av/bearhawk/cessna120skylight.jpg These Cessna 120/140 skylights are still available from LP Aero for about 37.00 each. Or buy a sheet of acrylic and make your own cuts. Mark Conover +++ #15920 From: Pat Fagan Subject: Re: Windows and skylights > A splash of gasoline can cause crazing and cracking on unprotected > Lexan (polycarbonate). It would be a good idea to use Plexiglass on the side(door) windows for just this reason. The tank drain plug sits above the open window and you can't help getting a drip or two on it after you sample the fuel. Pat Fagan +++ #15939 From: "t18cox" Subject: Re: Digest Number 1169 One of the guys here is doing his second Airtech job. It is all polyurethane glues, primer and paint over ceconite. It is slick. Dave likes working with it, but he thinks it's heavy relative to Stits. I don't think he actually weighed it tho. Try their website. http://www.airtechcoatings.com/faq.html Bill Cox +++ #15941 From: Budd Davisson Subject: Re: covering Re: covering -- Aircraft covering ranks right up there with gun control, abortion and religion, as one of the most controversial, emotionally heated subjects in the world. So, I'm going to make a flat statement and then back out and let everyone vent their opinions and offer no rebuttal: I've been messing with fabric covered airplanes for 46 years. I've used everything from nitrate and cotton bed sheets to Razorback and barn paint and I'll only recommend one system as being fool proof and with guaranteed long term shrinking and adhesion properties: the Stits/Polyfiber system. Use it through silver then go with a high quality, urethane or whatever you want to use, but don't screw around with anything but Stits for the build-up. If you're a pro and have a favorite system, go with it. But most of us are amateurs and for us, Stits is the way to go. Okay. Fire away! bd +++ #15950 From: "t18cox" Subject: Re: Another covering question There are a lot of fabric airplanes out there with multiple paint jobs on them. Each one adds weight, typically 30+ pounds. As far as I know you can not chemically strip fabric. Butyrate dope or Polytone can be rejuvenated when they get old and cracked, then retopcoated. There is still some weight buildup but not like repainting periodically with enamel or polyurethane. As far as the fabric surviving over the years if you use ceconite, polyfiber, or some similar dacron fabric and protect it from the sun it will last in excess of 20 years easily. I like aluminum such as Polyspray for my UV protection. Airtech and several other systems are using a chemical UV protection. Will it hold up? Don't know. I know the aluminum will. An airshow Stearman here was covered in Ceconite with no Aluminum dope.(some theory of the owner)It was rotten in 4 years. A Cub I recovered with Stits in 1968 come through the shop in the late 90's and would still punch 80+(Maule tester). Bill Cox +++ #15951 From: Ken Beanlands Subject: Re: Another covering question Some covering systems have the ability to be rejuvinated by applying a chemical to the coating. However, if it were my airplane and it needed a new paint job, I would replace the cover as well. Over half of the covering and finishing time for the Christavia has been in prepping and painting the final coats. It also accounts for 2/3 the cost of the covering system. If you were going to go through the trouble of stripping or prepping the cover for another coat of paint, it would make a lot of sense to pull the cover off and replace it as well. You will likely have several unsightly patches on the cover by that time and there would always be a worry that the fabric would require replacement soon after your new paint. I don't know I here are any strippers that you would want to use over fabric as the chemicals would probably affect the fabric as well. Using a heat gun is definitely out as the paint melts at a lot higher temp than the fabric. So, any repaintig will have to be done over the old paint which, of course, adds significant weight. Once you cover the plane you will realize that it's not that hard of a chore and will not be that expensive (especially the BH as it has aluminum wings). I would suspect that you can cover the fuselage, tail and LG for about $1200-$1500 USD. So, my reccommendation would be to recover the plane rather than repaint. It will last a good 15-20 trouble free years and will be a lot lighter and most likely, less expensivein the long run. Besides, pulling the fabric off the airframe every 15-20 years provides a good opportunity to check the condition of the underlying structure for hidden damage like buckling from overstressing, fatigue cracking and corrosion. Ken Beanlands B.Eng (Aerospace) +++ #16027 From: "Greco, Bob" Subject: RE: Re: covering I agree with Budd. Personal experience with water based Blue River fabric and finish system on my Pacer. The entire system is water based, no fumes, no smell, able to move the cloth around for several minutes after applying, able to press the edge of tapes into the cement, sticks real good to the structure, etc, etc. Easiest fabric system to apply that I have ever used and I have been recovering planes since 1963. It looked great and won trophies at various fly-ins. The covering was five years old when I took the plane to the Copperstate fly-in. A month after winning at Copperstate, I was in the hanger (the plane has always been hangered) and noticed cracks in the tail surfaces. Another month and cracks were showing over the entire airplane. I contacted the manufacturer and they supplied all the materials for a complete recover (which I still have in the original package). The manufacturer said that the plasticizer used to keep the urethane finish flexible continues to outgas and disappear over time which results in a brittle & crack prone surface (very similar to an enamel finish). This is the same problem they had on the Piper factory finished Super Cubs and Pawnees. They have since stopped selling this type of finish. The AFS system appears to be exactly the same material as the Blue River judging from the information that I recieved from AFS. I used the Stitts process for the recover and the finish is still great after about 10 years. +++ #16030 From: Ken Beanlands Subject: RE: Re: covering I was well aware of this going in. However, according to them, the topcoat that AFS uses is NOT the same as the Blue River stuff and, believe me, it's very flexible. I sprayed some out on some wax paper and even after several months, it has the same "stretchability" as a grocery plastic bag in that it will stretch to about twice it's size before bursting. I took the training course about 4 years ago and the cover piece we did them is still bery flexible today. I recently did a short covering seminar and used it as an example. It can still be folded in half and creases with absolutely no signs of cracking. Hope this helps. Ken Beanlands B.Eng (Aerospace) +++ #17503 From: Russ and Penny Erb Subject: RE: Bearhawk logo > Does anyone have a higher resolution scan of the bearhawk logo than > is on Erbmans CD? Which logo do you mean? The stylized word "Bearhawk" is available as a Powerpoint file at http://www.eaa1000.av.org/pix/erbpix/erbpix.htm It's also on your CD at \colorsch\bhname3.ppt If you mean the face of the Bear, I've never done anything with that. Russ Erb +++ #17518 From: "John Thompson" Subject: Bearhawk Logo I mean the "Bearhawk" word logo, like on your CD. The one on the CD is pretty low res, bad case of jaggies if you try to enlarge it. I was thinking of taking it to a sign shop and see what they can do with it. John +++ #17520 From: Russ and Penny Erb Subject: RE: Bearhawk Logo Did you look at the Powerpoint file on the CD? Russ Erb +++ #17587 From: calbru@a... Subject: Re: fabric weight The Beartracks issue which describes casting the lead aileron counter-weight mentions the weight per SF of fabric and paint. I assume that it's refering to SF of fabric, not SF of surface--which would be double that of fabric alone. (top and bottom) Anyone know for sure? Perfecting the elevator counter weights, Cal B +++ #17590 From: Russ and Penny Erb Subject: RE: fabric weight The weight is for each square foot of actual fabric. That means you have to add the area of the top to the area of the bottom. Think "surface area" or "wetted area"--if you dropped the whole thing into the bay while visiting Planter Bob and it sank, how much area would get wet. Another way--how much area of fabric do you have to buy to cover it (not counting scraps)? Russ Erb +++ $Id: 2.3.5-Fuse-Covering,v 1.12 2003/05/22 03:24:53 bentonh Exp $