Koverall for Hinges?

Stuka Stunt Main Forum · 10 of 10 known posts recovered

VolvoBird · Oct 24, 2000 10:46 AM

Even though they present some construction and finishing difficulties, I have a preference for cloth hinges applied nearly full span on both flaps and elevators. The precut hinges sold by Brodak, Sig, etc., are too thick and do not apply very well with clear dope. Various persons have suggested lightweight dacron and chiffon. But, recently I have seen Sig's Koverall suggested as hinge material for an electric.
Has anyone used Koverall as hinge material? Was it satisfactory (i.e., was it easy to install, did it remain flexible, and was it durable)? Would you suggest its use for planes up to 40 size?
Thanks for any suggestions you might have.

kdheath · Oct 24, 2000 04:19 PM

#1 source

I used to use monokote for hinges on RC planes up to 40 size and never had a failure of any kind. I have not tried Koverall, but I think it would work really well. What we did was iron two strips of the covering together adhesive to adhesive along one edge. The strips are about 3/4 inch wide and the overlap about the thickness of the surface to be hinged. Then cut the hinges into individual pieces of whatever width you like. Next, iron strips of the covering along the edges to be hinged together. Now hinge just like you would like glue-on cloth hinges. Last cover the surfaces, hinges and all, with the rest of your regular coverings and paint. The surfaces are sealed, if you run the hinges all the way across, and very secure. I have done this on RC planes like a 40 Kaos without any problems.

VolvoBird · Oct 24, 2000 07:22 PM

#4 source

KDHEATH:
Thanks for your suggestion. However, I do not think that Koverall has adhesive on it as does Monokote. Also, I would hope to apply Koverall hinges the same way one would conventional glue-on hinges, except that I would use clear dope instead of glue. And, just to demonstrate what a traditionalist I am, these hinges would be used in conjunction with good old silk span covering.
The Monokote hinges are intriguing, however. You might be interested to know that the same procedure was suggested in the building instructions for the Top Flite "Tutor." If I can ever get over my hangup about using silkspan and decide to try Monokote, I think I will use your idea. But, believe it or not, I really enjoy covering with silkspan and dope. Sure, it takes a lot longer, but I find it rewarding to watch the finish evolve, coat by coat, from rough paper to the smooth, deep gloss one can get from silkspan and dope.
Thanks again for your suggestion.

Steve Helmick · Oct 24, 2000 09:35 PM

#5 source

Nils says he uses "BalsaRite" (same as SIG Stix-it, I think) to apply linen hinges with a Monokote Iron. A second coat over. I don't see why it wouldn't work reasonably well, but as for being a sealed hingeline...NOT! As an alternative, take a look at Fourmost Products Demountable hinge, P/N 141. I saw these at the Model Expo, and bought some. Last year they had two sample surfaces hinged, and I held this up to the light, and I swear, I could not see light through the hingeline. It's a modern, nylon version of the old "tube & wire" hinges, which I happen to think is a pretty neat idea. The only hitch with these is that the surfaces need to be 1/4" thick, tho you could deal with more, less wouldn't work. Each package does 36". I plan to use it on my BANSHEEsh, but if you have used it or get to try it first, please poste your findings! If you consider using mylar/monokote hinges, make up strips of pre-finished balsa, and just glue them to the flap and TE. This way, you can have the worst part of the finishing already done. Steve

Kelvin Heath · Oct 24, 2000 09:41 PM

#6 source

You're right, I was thinking of Coverite, which does have adhesive. I don't know why the Koverall wouldn't work, though, doped in place. I use a drop of Elmer's Carpenters Glue to stick hinges down and that seems to hold well and finishes out well with Sig dope. Sorry about the confusion.

Nils · Oct 24, 2000 11:40 PM

#7 source

LAST EDITED ON Oct-24-00 AT 11:44 PM (EST)

Oddly enough I already had this typed out so & C&P'ed----

I never had very good luck trying to glue cloth hinges on. I always got something crooked or a corner would curl up, or things would slide around or something. Now I iron 'em on using Balsarite. One wet coat of balsarite (let it dry to the touch) on each surface is enough to hold them in place while ironing them down initially. I iron half on one surface & the other half on the other surface. Align the two surfaces with the hinges over/under & weight them down on the bench so they can't move, with the loose ends of the hinges up. I use some 1 pound lead ingots made out of wheel weights & poured into an RSBS ingot mold, &/or sand bags. (I make my own bullets so I always have lots of lead ingots, very handy for building.) Pull gently on the loose ends of the hinges until the surfaces have no gap & iron them in place. Brush a coat of Balsarite over them wet enough to saturate the cloth, allow to dry for half an hour or so & give them one more coat. Give 'em a light sanding between coats. I smooth edges with Evercoat Metal Glaze if I want them to disappear. I've done the hinges this way all the way across the surface for a no-gap hingeline but generally I seal my hingelines with Crystal Clear 3M tape from the hardware store. My profile Oriental has well over 500 flights on it & it's starting to look a little ratty but the hinges are just fine.
Nils
P.S. I got tired of paying $1.29 for a little bag of hinges so I went to the yardgoods store & bought a yard of un-bleached muslin for $1.19. I already had a pair of pinking shears. Now I have enough cloth hinges to last me three lifetimes.

LNeumann · Oct 25, 2000 08:19 AM

#9 source

Using cloth hinges may be OK for sport planes, but I have never liked them--not even in the 50's when that was all we had. The nylon barrel hinges are so much nicer looking, easier to use, and more durable--and they are much easier to use in aligning the surfaces as well. With the barrel hinges if you cut the slots accurately on the center line, the surfaces will automatically line up. Even if you goof in cutting the slot, you can repair it BEFORE gluing the surfaces together. A slot cutting guide is a cheap tool to purchase and makes the cutting simple. With the cloth hinges, it is very easy to misalign the surfaces with one another as you apply them. So we end up ripping them off again, regluing, rehoping.

But there is an added benefit to all this--if you are trying to get a good finish on your plane. With the barrel hinges you can cut the slots, fit the parts together, and then finish everything BEFORE hinging the surfaces. It not only makes finishing easier, but leaves the hinge line clean and accurate without having dope sticking the surfaces together (or having to clean the dope off of the hinges afterwards).

A little trick that hasn't been mentioned is to bring the edge of the surfaces (trailing edge of wing and stabilizer, leading edge of flaps and elevators) to a 45 degree point. You can glue 1/4 inch triangle stock to these surfaces, or, Matthew has made a sanding tool where he can simply sand this edge in. That edge becomes the center line where you cut your hinge slots. Center your hinges in the slots (half of the barrel in the wing, half in the flap, etc.) and the surfaces will ride together with (and I hesitate to say this, because I am going to get jumped on now) no need to seal the hingeline. There simply is no gap. If you do wish (or need) to seal it, use thin clear packaging tape, and push it all the way into the slot. It will add very little stiffness, and look good, too.

If you go to the Nats you may see a few of the classic and OT ships using cloth hinges as they are trying to copy the spirit of the 50's, but you will NEVER see a serious contender using them for the modern competition. If they had an advantage, they would be used. If they have a disadvantage, they won't. They do, and they aren't.

Leonard Neumann

VolvoBird · Oct 25, 2000 07:08 AM

#8 source

Thank you Kelvin, Steve, and Nils! I especially appreciate the suggestions about using BalsaRite or Stix-It instead of dope and/or glue. Using either one of those would certainly make it a lot easier to reinstall any hinge that might not be just right after the first try.
Steve: I would appreciate it if you would elaborate a bit on your adverse comment about using Koverall for a sealed hinge line. Do you mean that placing hinges along the entire span of the flaps and/or elevators does not work well for sealing, or is there some other or additional objection (perhaps stiffness)?
I have seen the Fourmost Products hinges advertised in the Tower Hobby catalog, but have not seen or considered using them. When you have tried them, I would be interested in your experience/reaction.
Peter Hess

kdheath · Oct 25, 2000 05:16 PM

#10 source

Leonard, of course, hit the nail on the head about hinges. I disliked fabric hinges years ago when I was a kid trying to stick them down with Ambroid. I have used the thin plastic Zap-in type hinges for years on RC models with great success. They have the advantages of being light, invisible, cheap, easy to install, and non-critical. Leonard has a point, though, that if you can pull the hinge pin, it is easier to do your fit and finish work and repair damage later. I'm a hacker, though, so much less critical......

Steve Helmick · Oct 25, 2000 10:18 PM

#11 source

I would expect Koverall to be too porous, being very thin, compared to old linen hinges, to result in an air-tight hingeline. Glad Nils came along and posted his Balsa-Rite hinge technique. I used to use Ambroid on linen hinges and had compatability problems with Aero Gloss and maybe Testors. There wasn't anything else, no SIG. I think Leonard is referring to gluing the hinges in after painting, not pulling the pins and using a single piece pin. That can be done, but you will have a very bad gap. Paul Walker's first B-17 had tube & wire hinges, and it looked like a great solution, but Paul said they still needed sealing. He also says that "Billy" (Werwage) uses fabric
hinges, and doesn't need to seal the hingelines. I've talked to
Ralph Cooney (Fourmost Products) about his hinges, and he says they will work great. They're light, they don't seem like they would need sealing, BUT they are white. They can be dyed. I have no doubt that they will work fine, but like I said, you need 1/4"
surfaces. Don't wait for me to report on them, that's slower than waiting for Nils' grass to grow. You don't even need Matt's 45deg
chamfering tool. Snug lines, Steve