Bike tube wrapping questions

[HH~]

Belly Plate,

Its used to place over your lam stack as it sits in form back down. You lay the plate over your stack that’s taped so it cant slide, then you wrap over this plate not directly on your wood lams. Have a set for each form. Very effective at evening out the pressure from you tubing while wrapping.

HH~

[bownarra]

Always use a pressure strip on any thin FLAT wood backings. These are the most prone to cupping. An ali strip works with some flooring boo laminated to it works well. Make it 1/4  to 5/16th thick to prevent cupping.
With boo always cut boo backing to width plus some wiggle room then drill holes at the tips either side of the boo, use toothpicks inserted into the holes to stop the backing and stack getting out of line. Once this is done cut the rest of the core/belly lams to the same width as the backing strip. With this sort of lay-up there is no need for a pressure strip. The crown on the boo sorts everything out. If the belly lams are left wider than the boo backing you can get poor gluelines.
Check out the airhose and double form method. It really is the ultimate way to laminate. A lot of work to make good forms but you never get any problems.
I glue my glass bows up at 65 - 70 psi with EA40.
My guess at inner tube pressure would be around 60 psi.
I don't cut them up just leave them whole and pull till they bottom out. Wrap one way along the limb from grip to tip. Then wrap in the opposite direction from tip back to grip. This eliminates the layup getting twist glued into it. 4 tubes per lay-up

[Del the cat]

Wrap your hand or arm with a  maxed out inner tube and see how  it feels.  To some degree it all amounts to about the same.  You're not able to crush the wood so as soon as the surfaces contact it all becomes a bit superfluous.

I wouldn't advise doing that for more than a few seconds.
I think the pressure is a lot higher than many think... that is assuming that it is always being pulled as tight as possible whilst being wrapped.
I reckon one can easily be pulling say 30# whist wrapping and if the tube and bow are both 1" wide that's gotta be somewhere nea r30psi. then factor in some overlap or second layer... it's gotta be plenty
Del

[mmattockx]

Wrap one way along the limb from grip to tip. Then wrap in the opposite direction from tip back to grip. This eliminates the layup getting twist glued into it. 4 tubes per lay-up

That's a great tip, thanks.


Mark

[bownarra]

Wrap one way along the limb from grip to tip. Then wrap in the opposite direction from tip back to grip. This eliminates the layup getting twist glued into it. 4 tubes per lay-up

That's a great tip, thanks.


Mark

No problem Glad to help.

[Marc St Louis]

I've never used bike tubes.  I have always used large rubber bands, up to 3 or 4 of them at each location, see pic.  One of the first time I used this system, would have been in the early 2000's, was on a Bamboo backed Rosewood RD bow.  I had the bow all glued and reflexed waiting for the glue to set, I was using epoxy.  After awhile I heard a bang in my shop.  When I went to see what had happened I saw that the rubber bands had overpowered the Rosewood belly and snapped it.  I supported the belly after that.

Surely an indication of how much pressure rubber can exert.

[backtowood B2W]

Not many glue ups made but I use the bike tubes for steambendind with a set up like Marc shows in his picture. Got the race bike tubes....no need to slice and very durable that way.

[HH~]

Bike tubes, bands, surgical tubing all works.

I like tubes, cheap. Have fire hose form too but they no fun really.

HH~