Inner tubes versus air hose

[kiltedcelt]

Just wondering what you guys think. If you scroll down you can read about my mis-adventure with my first time using an air hose for clamping pressure. In the past I've done a couple fiberglass glue-ups using rubber bands as well as some all wood glue-ups as well. In all cases I've had perfectly acceptable results with rubber bands (inner tubes) and clamps. The only issues I've ever had were the result of poor fades coupled with a radical design that was likely going to cause major problems with the fades to begin with. The limbs have always had perfectly acceptable glue lines when I used the inner tubes. However, the take down longbow and recurve I'm building were from the Bingham instructions and they specify using the air hose method for clamping, so I built the form according to their instructions. I have seen some guys who make nice bows using only C-clamps and inner tubes so know it can be done. Is the air hose just used because you get even clamping pressure more quickly? It seems like with inner tubes and clamps you can get just as good of a glue up. I'm curious as to pros and cons and how many of you use inner tubes versus air hose.

[SourOwl]

Kiltedcelt - I have used both methods in the past, a couple of em were Bingham kits, a couple were my own design.  IMHO, both do a good job.  Some think the air hose simply guarantees very even pressure, where the rubber bands and clamps won't be quite as exact, because you may not pull the bands with the same stretch each wrap, or tighten the clamps the same.

I have enjoyed perfectly acceptable results from both methods too.

I would use either method again with no qualms.   Sourowl

[JamesV]

I get great results with the rubber bands. The forms are a lot easier to build for me. I clamp the riser area and double lace the limbs with the rubber bands............James

[kiltedcelt]

I always double up on the inner tubes crossing over each other from opposite sides of the form. I think if the pegs are close enough together you also get really good clamping pressure and pretty even along the whole limb length. My first try with the air hose has been a failure for several reasons so any further glue ups I'm going to stick with inner tubes because they're what I know best and I know I can get a good glue line with them. Setting up and using air hose is just too many variables for me and I don't want to keep trashing lams and glass trying to get it all figured out.

[Scott F]

Rip your rubber bands into 3/8" strips and it will work out better for you than if you simply cut the tire innertube in half.

[kiltedcelt]

I use the most skinny of the inner tubes I can find and leave them whole. I only cut out the valve stem. I used to cut out the valve stem and then cut them lengthwise into two separate strips but then they only lasted through one, maybe two bows before they'd get torn and rip in half. Leaving them whole means they have more structural integrity (what with getting glue on them), and you can flare them out to full thickness going over the lams which helps spread out that clamping pressure more. I also feel like leaving them whole allows for a little less stress and again, more clamping pressure.

[hova]

i never understood why you guys cut an inner tube... i always wanted to try leaving them whole for my first lam bow , now i know i will.


thanks
-hov

[kiltedcelt]

Hova - as I mentioned, I used to cut out the valve stem and then slit them lengthwise. By doing that you get two strips out of one tube but I've found you can get more tension by leaving them whole and you will get some glue on them regardless. When they're whole a lot of the time you can pull at them and get them back into shape where you can use them again at least another time if not a couple more times. When you slit them lengthwise and make the single thickness strips, if they get glue on them and get bunched up then they won't stretch well there anymore and they also tend to tear more easily. If you slit them lengthwise then you're probably only going to get one use out of them, at least the way I've done my glue-ups before. However, I did just have an idea about using the narrow stretch wrap that comes on a roll to wrap the whole lam stack before laying in the form. I saw a video once where I guy wrapped the stack of glued lams using the shrink wrap and it had the effect of squeezing out the excess glue as he went along. He then put is lams on his form and clamped them down. It looks like at the very least it would eliminate most of the glue squeezing out of the sides as you start applying clamping pressure. In the past I've tried wrapping plastic wrap around the glued up stack but the glue still ends up gooping out the sides and I have a whole bunch of excess glue to clean off when the limbs come out the oven. Seems like wrapping the stack with shrink wrap to begin with would eliminate most of that squeeze-out and then the inner tube would only have to be tight enough to force the lams to conform to the shape of the form.

[John Cooper]

I have used the inner tube method for a few bows now with great results.  I use resorcinol because of the longer working time.  Before I wrap with the tubes, I wrap in seran wrap to avoid a sticky mess!  Then I start in the middle, wrap to the tip, down again to the middle back to the other tip than back to the middle.  The only bad part is my hands get really cramped about 2/3rds of the way through!

[jess stuart]

All of my tubes were made from truck (semi) tubes, much thicker than bicycle or car tubes.  I got used ones free for the asking.  I never used the pegs on the side of the form, just wrapped completely around the form bow and all.  If you want more clamping pressure just add another layer.  Some of my tube strips are years old and have been used many times.

[JamesV]

I took a large tractor intertube and spiral cut it about 1 1/2 inches wide. Half the tube made a strip over 90 feet long. My form has pegs and I lace it like a shoe, then dubble back for a second layer. I use clamps on the riser area and fades. Always get good glue lines and the rubber last forever.

[Scott F]

Wrap a bow blank (without glue) with a tube that is 3/8" - 1/2" wide, then wrap it with a full (or half) tube and see which one tires out your grip!  I have achieved better glue lines when I rip the tubes to approximately 3/8", ymmv.

[DEATHMASTER]

I see Apex has a extra piece in when he glues up with the tube. Do any others use a special secret when using the tube method?

[Scott F]

Wrapping the tube tightly places most of the stress on the edges of the bow form since it is (usually) 1.5" wide and flat.  Putting anything flexible down the center of the form prior to wrapping the bow will enable you to keep the tube pressing evenly along the entire width of the limbs while the bow is curing.  I usually use a scrap of wood that is approximately 1/2" thinner than my bow form.  It is around 1/8" thick so that it is capable of bending to the r/d portion of my forms.

[hova]

well at first i thought you guys were cutting them like doughnuts , across. that would make some sense to me , as if you found the right diameter tube , you could use them just like regular rubber bands...


the skring wrap idea is a good one , i used to do packing for a big **** seller , and we used to get saran wrap sort of stuff , then hit it with a blow dryer or heatgun and it would tighten up. if you rolled the stuff around itself , it would make an extremely strong rope , and if you heated that , it would compress much like it normally did. i used to use it in conjunction with foam pads for delicate antiques , with a pad on each side , and then wrapped with the rope , then heated , and nothing ever got broken in transit.


my way of testing my packing was to throw it down the stairs. if it cant take stairs , it cant take shipping guys throwing it...

-hov

[David Ricke]

I use both methods bad part about air is when it leaks.  Knifemaker

[Swissbow]

I have only used the rubber band method and it worked well so far. If you can't apply enough pressure to make everything fit nicely without some air bubbles in it, then your riser doesn't fit the form or the radius at the fades is to small or to steep. I always do a dry run before glue up and if I can't press the lams to fit the riser with one hand, then I know that I have to rework it until it fits perfectly.

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Andy