Primitive Archer
Main Discussion Area => Bows => Topic started by: Onebowonder on August 06, 2014, 10:49:01 am
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Hey guys. I'm doing a glue-up bow and need to use bicycle inner tube bands to provide grip while the glue cures. How do you guys make these bands? Do you leave them whole like a tube? ...or split them out so that the bands are a single layer of rubber? If the latter, what width do you consider ideal for this application? Do you make one really wide flat band or split the tube into two or three or <gasp> maybe even four narrower bands?
My internet searches have given me multiple answers to the above questions, ...each claiming to be correct. I figured I'd come to this group to get the gospel truth of the issue!
Pix would be great if you have them! Though I claim to be literate on most of my job applications, I really function and learn best at the 'K' end of the 'K thru 12' spectrum. ;D :o ::)
OneBow
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They squeeze a lot of glue out if your not very careful. Like an Ace bandage on a leg, it doesn't feel tight, but it is very tight and constrictive. Maybe try rubber bands or small c clamps. Or, just be careful to leave plenty of glue behind.
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about 1" to 1.5" single thickness, bind 'em round overlapping slightly. One layer should be enough, gives you a good work out too :laugh:.
I actually use rubber roofing sheet left over from when I re-roofed our extension, but I have used car inner tube before, scrounged from the local tyre place.
Short 1/2" wide ones are v handy for strapping down overlays etc while they glue even when using CA.
Del
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I cut little ones across the grain of the tube, making little black rubber circles. Great for doing small jobs. Then I cut the tubes lengthwise into various widths from quarter inch wide up to inch wide. From there, they get cut shorter and shorter as I use them for various tasks until I throw out the scraps or they get goobered up with glue.
Every few years I stop by a bike shop and ask for any busted inner tubes and walk out with an armload.
But like PD says, they will compound pressure with every wrap eventually crushing whatever they are wrapped around. You can do this with a watermelon, it's hilarious!
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I use bike inner tubes as well for my titebond 3 glue-ups. Bike inner tubes come is different sizes. Obviously in shorter and longer lengths, depending on the tire size. But racing bikes have narrower tires and thus narrower inner tubes. Most common tires are 1 3/8" x 1 5/8" in diameter. Myself, I cut these in half lengthwise, using a pair of scissors. If you don't cut them in half, I personally find them too stiff and difficult to stretch to do the glue up. A half tube is just elastic enough to easily stretch it, yet apply plenty of pressure on the laminations. However, I'm convinced a whole inner tube will work as well.
One inner tube is enough to do a glue up (as long as you cut it in two strips). But myself I prefer to wrap the glue-up twice: once from top to bottom and once from bottom to top. The inner tube wraps are then crossing over, which applies a more even pressure than wrapping once. The pressure sides level out, if you know what I mean. If you want to wrap the glue-up twice, you'll need about three half inner tube strips. I recommend to start with one strip and overlap the next one, by just going over the loose end. I don't like one long string of inner tube strips all tied together, because it is less easy to manoeuvre and creates knots at the junctions which can get into the way when you want to clamp the glue-up into a form such as reflex(/deflex).
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All I do is cut the one inch section where the valve is, as far as getting them to tight as you wrap as long as the glue runs in front of the wrap you are tight enough, if you use epoxie u can use stretch wrap
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But like PD says, they will compound pressure with every wrap eventually crushing whatever they are wrapped around. You can do this with a watermelon, it's hilarious!
You just cheered up a stuffy day in the office JW ;D
Note to self, buy watermelon :laugh:
Del
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Do you do anything to keep the glue off the inner tube or does it matter?
Grady
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Glue won't really stick to the tube unless you stretch it excessively and use Epoxy.
Inner tubes also vary greatly in thickness so there is no one answer as to what width to cut. Just experiment and find what works best for you.
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So, UniBond 800 (aka the glue formerly known as URAC 185) isn't going to stick to these bands then, right? It's a urea based glue - not an epoxy. I don't recall having an issue with it previously, ...but it's been a while.
OneBow
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I do what bubby does...cut the valve part out and I'm good to go..and you won't have a problem using that glue with them
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I use them whole. well cut out the sectioin witht he stem. I have racing bike and mountain bike tubes.
i get them for free from my local bike shop mechanic. for Tight bond kinds of glue ups i'd say leave little gaps between wrappings and be careful not to squeeze out all the glue. You might be better off with a milliong little spring clamps unless you are also pulling the bow to a form.
For gap filling glues pull away.
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I cut the valve part out and split the tube in half lengthwise. I don't do many glue up but have gotten my best glue lines using bike tubes. You may have to use clamps at the fades. I have on some but not on others. I've used this method with Urac and TB glues. All you have to do is stretch the bands and the cured glue will release.
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Yes just cut the valve section out and you're ready.
One important thing to do is wrap each half twice but do one wrap clockwise leaving enough room between wraps to fit an anti-clockwise wrap on the way back to the handle. This stops twist being imparted to the glue-up which can happen if you only wrap in one direction around the lams and form.
Also tape the lams in place before starting to wrap with the tube.
Don't be scared to put plenty of pressure on the wraps.
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I'll add my .02 cents as both someone who's used this clamping method and as a cyclist with loads of used tubes laying around. The best tubes as someone mentioned are the skinnier ones. If you go to a bike shop you might be able to get them to give you tubes that they pull out of tires that needed patching or where throwaways because the puncture was not repairable. You're looking for tubes that are labeled for 700c - this means they're for road bikes and are the skinnier variety. Alternatively you could go to a Performance Bike, store (if you've got one nearby - it's a nationwide chain), as they sell tubes typically at 5 for $15. I cut the valve stem section out then slit the tube lengthwise into two even strips. I use the strips so that I can alternate with two of them to get a kind of X pattern when doing the glue-up. Glue will get on them though and I find you can usually get maybe two or at the most three glue-ups out of a strip before it starts splitting or cracking where the glue has built up. I think I typically can do a single bow with two inner tubes which is equal to 4 strips. I still use clamps around the handle and fades, and tips, especially if I'm doing anything with a R/D shape or anything with reflexed tips.