Glue that survives steam/heat bending...

[Bearded bowyer]

Hi all
I've been wondering...........
Do any of you know of a glue that you can use to build a bi/tri laminate bow that wont fail if you heat/ steam bend it?
I use cascamite mostly and have been thinking about introducing a slight recurve post glue up.
Do all glues fail with heat/ steam?
I can glue them on a reflexed former but was wondering if it can be done after... as an after thought, it my also help if limb string alignment goes horribly wrong....not that it ever does...
Thanks
Matt

[Pat B]

Matt, I have heard that Urac can take some heat and steam but Urac isn't made any more. Now it is called Unibond. Whether it still has the same heat resistant properties I don't know.
 It is going to be difficult bending a lam bow after glue-up.  You might be able to make some minor adjustments but not adding recurves. The glue joint(s) will fight you. You would be better off pre-bending the components first then glue up the bow.  If you don't already have it, try to find a copy of Dean Torges' DVD, "Hunting The Bamboo Backed Bows". Lots of good info about building lam bows with straight, R/D and recurved limbs and Dean shows his simple inexpensive form for building lam bows in all 3 configurations.

[lesken2011]

Since I make a mostly backed bows, I started kerfing them when I want to add reflex to the tips. It is kinda spooky the first time to cut into the tips of a fully functioning bow, but when the glue dries and you see the finished product, it is worth it.

[Newindian]

I think heat treated tight bond is supposed stand up to boiling water, might be worth looking into

[Bryce]

I pre bend my belly stock. And if I want more reflex you can glue more reflex into it.

[Bearded bowyer]

I just read that tight bond bonded joints etc can be disassembled using a heat gun/ steam......

[Newindian]

Yes but at a certain temperature you can activate a secondary bond that is stronger then the first which tight bond claims stays together in boiling water, there was a post on it sometime back but I can seam to find it

[Bearded bowyer]

Thanks Newindian
I think the best thing to do is to try it.
when I have time I will glue up some scrap wood with tight bond 3 ( which I have) and with cascamite and probably usual pva.
then I will try stream/ hot gun bending.
Is anyone interested in the results? if so I will post them.
Any comment on the type of timber being used?
Matt

[Pat B]

Everyone would be interested in the results!

[mikekeswick]

Resourcinol is very good under heat.
However the way to do what you want is simply to get your lams thin enough and use a form to get the shape you want. If you can't get your lams thin nenough then as mentioned kerf cutting is the way to go.

[AttieBotes]

Balcotan. Its a product of the company Brummer. Its waterproof and can be boiled or steamed as it is used in the production of wooden boats. Some of the bowyeurs here in South Africa have started using it with great success.

[Bearded bowyer]

Just done a bit of web searching
Balcotan is no longer available in the uk.
I have an old hickory lemon wood longbow, cascamite glue up, bi-lam I never finished so I will steam one end, and hot gun the other and let you all know what happens. I'm going to try to put a big re-curve into the tips so this is an extreme bend, and if it works I will be quite surprised......But if it does......

[Newindian]

Found this on a tradgang thread

 posted May 29, 2013 04:35 PM                         
Okay just got off the phone with titebond....Sounds like we are BOTH right.   

TitebondIII deos soften at 150 degrees.

However when heated above 150 (160-180 degrees) then allowed to cool it activates a secondary cross-linking in the glue making it SUPER strong! After it has been heated to temps between 160-180 then allowed to cool it becomes so strong and impervious to heat it will not come apart when soaked in boiling water (they actually test for this).

Hope this helps

Tenbrook

[mikekeswick]

Seriously get some resourcinol and learn to cut accurate kerfs!

[zenart]

Found this on a tradgang thread

 posted May 29, 2013 04:35 PM                         
Okay just got off the phone with titebond....Sounds like we are BOTH right.   

TitebondIII deos soften at 150 degrees.

However when heated above 150 (160-180 degrees) then allowed to cool it activates a secondary cross-linking in the glue making it SUPER strong! After it has been heated to temps between 160-180 then allowed to cool it becomes so strong and impervious to heat it will not come apart when soaked in boiling water (they actually test for this).

Hope this helps

Tenbrook

I'm curious to know if doing this 'secondary strengthening' causes TBIII to become less elastic even to the point of brittle. Yes, may be stronger in a static bond but we are asking it to flex.