Glueing-up: Air hose or clamps or tyre tubes?

[Benny Nganabbarru]

More scheming...

Are clamps or rubber tyre tube sections just as effective as air hose when glueing-up? What are the relative merits?

Cheers,

Ben

[Gringa Bows]

Ben,i like using the inner tube,it works for me but i intend to try the air hose in the future ,i think it would be easier to clamp the bows to the form with the hose................Rod

[otis.drum]

from what i understyand, with an air hose you need to have a two piece form and can only make the same shapped bow each time. i like the tyre tubes as i can change the shape of each bow, make forward and rear handles, change handle lengths, adjust reflex.

[Gringa Bows]

Good points Otis...............Rod

[greybeard]

If you are only going to make one or two bows, clamps or rubber tube should suffice.

In a bowmaking workshop situation I use clamps and the glue-up is done in two stages. The client has ten components to glue and assemble and with a pot life of about 45 minutes for the epoxy it is putting too much work at risk to attempt a single glue-up.

For the reasons Otis mentioned I am using clamps. When I settle on two or three designs I will go to the air hose and two piece form.

Daryl.

[Benny Nganabbarru]

Thanks, fellows. Greybeard: Can glueing-up be done in stages including wrapping in black plastic and putting it out in the sun? In other words, once heat-treated and set, can the process be done again for another section of the bow? In yet more "other words", can an already glued and set bow go through the process again without detriment or not? I should learn to be succinct.

[greybeard]

Hi Ben,

The first glue-up [which incorporates the back glass, two laminations and handle] are left clamped up overnight on the workbench.

The following day the clamps and pressure strips can be removed. A final ‘feathering’ can be done to the fadeouts if needed and the belly lamination and glass is then glued on, clamped and left overnight on the work bench.

Next day the bow can be ‘roughed’ out and tip overlays added.

Generally the bow has had 72 hours for the two pack epoxy to air cure before you start loading up the limbs.

I have only ever used ambient temperature to cure Techniglue and have not experienced any problems. In summer my workshop may reach 35 or more degrees. I believe there may be applications where an elevated temperature could improve the bond strength of some two pack epoxies.

Daryl.

[roscoe]

grey beard
do you just wipe the excess glue that squeezes out from infront of the fade outs and then when it cures give it a light scrape? so iam not wasting to much glue, what would i measure out for a 72" longbow 1 1/12" wide for the back glass, two lams and riser? Whats the best form for using clamps and tyre tubes ( dimensions ) and configurations? sorry for all the questions. I would like to get it right the first time. Its been raining and very humid so iam waiting for the weather to improve before i glue up and reading about doing it in stages sounds like a go idea to me.
thanks ross

[otis.drum]

getting windy down there ross?

[Mububban]

Where do you source your inner tubes rom? Do you buy cheap ones from a store, or do you raid the bins of bicycle and car repair places?

If I'm using Titebond wood glue for bamboo board selfbows wrapped in inner tubes, will the tubing be able to be recycled, or do you need to cut/scrape the tubes off so you're always replacing the tubing?

The only 2-layer stave I've made so far used Titebond II and a whole heap of plastic springy clamps, not the screw style. So far it's held together after several hundred shots and hasn't shown any glue voids.

[otis.drum]

go to a bob janes or other car/truck tyre joint and get old ones with punctures in them for free. i don't use bicycle tubes.

[GrahameA]

Afternoon Kevin

If I'm using Titebond wood glue for bamboo board selfbows wrapped in inner tubes, will the tubing be able to be recycled, or do you need to cut/scrape the tubes off so you're always replacing the tubing?

The only 2-layer stave I've made so far used Titebond II and a whole heap of plastic springy clamps, not the screw style. So far it's held together after several hundred shots and hasn't shown any glue voids.

1. If you do not want your rubber strips (bands) sticking to the bow as you glue it up put a layer of cling wrap over it before you apply the rubber strips (bands).

2. The plastic sping clamps can work well - in some ways I like them as they do not come loose.

3. You only get to see the glue voids when it comes apart.

[Ol Man]

Going to throw my 2 cents in for you.

I use 1/2" x 3" rubber bands that I buy in bulk. After I use them (I use a heat bow) I discard them. They are inexpensive and I can get a lot of pressure from them.

[Stickbow Hunter]

I used clamps initially but now I much prefer the air hose system. The air hose gives good even gluing pressure and is easier than using clamps.

I wouldn't consider doing glue-up of a wood/glass composite bow in stages because IMO it makes the job more difficult - contamination of wood gluing surfaces being of major concern. I use Smooth-On and it has a good pot life which allows plenty of time for glue-up.

Jeff

[UPTHETOP]

Hey Jeff I see on some build alongs when using the air hose (which i did) they put 20lb in first for 5 min, then 40lb for another 5 min and finish with 60lb all up. The theory being it allows time for the air bubbles if any to pass to the side and not get trapped.
Silly me on my first bow used clear glass and yes had a few small bubbles trapped and wondered if i used the above method I would of had a bubble free bow.
But next time will youse colour glass which should also fix the problem.He He.
Do you think adding the air pressure slowly would help?

Thanks Wayno

[Stickbow Hunter]

Do you think adding the air pressure slowly would help?

Wayno,

Yes. I only put around 10 pound of air pressure in to start with and leave it a few minutes and then increase poundage to 15 - 20 pound for a further few minutes and then pump up to the pressure I want which is around 65 pound. I haven't had any problems with air bubles myself but I have seen them in other bows.

Jeff

[pdccr]

If i was using clear glass on wood and clamps would it be likely that i would have air bubbles?

[Stickbow Hunter]

Toby,

If you just put light pressure on the lams with the clamps first and then go along each clamp and make them tigher I don't see why you should have problems with air bubbles. I used clamps back in the 1980's and early 1990's and didn't have problems with air bubbles.

Jeff

[pdccr]

Ok thats good. How many clamps should i use, i was thinking around 10-15.

[Stickbow Hunter]

More the better IMO and make sure you have a good thick pressure strip between the glass and clamps to help distribute a more even pressure. If you don't your bow limbs will have light indents wherever your clamps were positioned.

Jeff

[greybeard]

Hi Toby,

My clamp spacing is around 2 1/2". I use a pressure strip made up of one 1.5 mm hardwood strip, a strip of 6mm high density rubber and a strip of three ply. It may not be fancy but it works.

New Recurve 003.jpg (92.28 KiB) Viewed 3235 times

Daryl.

[GrahameA]

Good Morning

Ok thats good. How many clamps should i use, i was thinking around 10-15.

If you look at the photo in Greybeards post above there are around 25 clamps on that bow.

In the Yumi photo below there are about 50 - but that is a bit more than normal.