Does anyone know where you can buy the material that is used for the live hinging in our jets? I am referring to the hinging that is used during the layup of the ailerons, flaps, etc. in the molds. Thanks, Gary

Gary,
it seems that most of the planes these days use peel ply for the hinging, it used to be kevlar but it's a pain to work with, i have a skymaster VJ2M and it's all done with peel ply, i have seen the hinging on an Ultra Bandit, again, peel ply. i have just made a set of parts for a new plane and used it for the hinges for the first time and had much more sucess than i did with kevlar.

Rich.

peel ply is polyester fabric right? I know some hinges are made from Spectre cloth as well.

Rich, thanks for the info. Somehow the hinge line needs to scored or something so that the hinge line is straight. Do you know how this is done?

Gary,
i am only learning all this recently, i am using a ply template which i tape to the surface of the wing and then use the tip of a needle file to file a line through the glass which covers the hinge material, just a little at a time until it moves freely, i cut the inner glass of the skin laminate before i join the two halfs of the wing in the mould so once it's cured and out of the mould i just have to cut through the opposite surface (with my template as a guide again) and the ends of the control surface, then i work on the hinge line with the needle file until it moves freely.
the parts i have made recently have come out very nicely, my wings have ailerons, flaps and gear doors all live hinged, it's taken a few attempts to get it right and the peel ply has worked much better than the kevlar ever did, could just have been me though.
before i had the templates made i just used to tape a metal straight edge to the surface and use that to guide the file.

hope that helps,

Rich.

OK, its not worthless but it would help a lot! What is peel ply and where do you get it?

Peel Ply is a fabric that is used when laying up molded parts. Most places that stock fiber glass cloth will have it.

You can find it sometimes in the Fab Dept of Walmart or places like Joe anns Fabrics. It's used as liners for curtians and such!!

i have finished hinging the parts of my current model now, i did the elevators last night and thought when i finished that i should have made a video, i'll do some pictures and video next time if nobody else does first, but it's going to be a couple of weeks until i make some more parts.

Rich.

Are there different types of peel ply ? It's my understanding that peel ply is used in in a wet layup to soak up excess resin and can easily be pulled away as witnessed here in one of Bob's videos at the 6:40 time mark... http://www.youtube.com/watch?v=wVQZy9AVxpY&feature=player_embedded#!
If the peel ply is being used as a hinge, how does it remain secure in the sandwich layup ?

Not sure it 'soaks up' resin just prepares the surface so that when it is removed after the curing process the surface of the resin is free from the waxy finish so that formers and such can be easily bonded without major sanding sessions.
Its my understanding, but maybe a member who knows about this can confirm either way.

marcs

Rip stop is what your looking for.

Thanks guys, I need to repair a flap that has a small tear. Not sure if this will work for that or if it only works during lay-up. I'll check out the what those places have and hopefully I can lay some in from the bottom of the flap.