Primitive Archer

Main Discussion Area => Bows => Topic started by: Josh on October 06, 2009, 06:34:36 pm

Title: heat curing Urac 185/heat treating bamboo
Post by: Josh on October 06, 2009, 06:34:36 pm

Hey guys

I recently purchased a piece of bamboo and some Urac 185 glue from 3 rivers. 

I have two questions:

I am doing a bamboo-backed ipe bow and I don't have a hot box.  I know you don't necessarily HAVE to heat cure the urac to get it to cure but my question is does it make the glue adhere better if you do heat cure or is it just to make it dry faster?  If it adds to the strength of the glue joint then I will go ahead and build my hot box (I was planning one anyway) just dont really have the time/resources/money to do one yet.

Also should I heat treat the belly of the bamboo after I plane it flat before I glue it all together?  It is just the raw bamboo from 3 rivers archery.  Does this add to the strength/performance of the boo?   Thanks for looking guys.   :)

-josh

Title: Re: heat curing Urac 185/heat treating bamboo
Post by: Dano on October 06, 2009, 07:05:04 pm

Urac just takes longer to cure at lower temps. I have never heat treated bamboo for a backing, the only time I've heard of doing it was for a belly lamination.

Title: Re: heat curing Urac 185/heat treating bamboo
Post by: knightd on October 06, 2009, 07:41:16 pm

You would not heat treat the belly of the boo.. If you are going to heat treat it you would do it on the node side.. but it is not needed on a backing strip.. The urac will just take longer to cure out.. I would recomend having it at 70 deg or above.. If you get below 65 deg it could be a problem..IMO

Title: Re: heat curing Urac 185/heat treating bamboo
Post by: Swamp Bow on October 06, 2009, 11:04:05 pm

I might be in the same boat soon, how many hours above 70*F does it need to have in order to be cured?  I live in S.FL, and as we get into late summer here, it gets below 65* at night for a while, but the days are still plenty warm (94* with a heat index of 105* tomorrow). To be safe let it sit for 2-3 days or 3-4 or ?

Swamp

Title: Re: heat curing Urac 185/heat treating bamboo
Post by: Jbell on October 06, 2009, 11:26:26 pm

Quote from: Swamp Bow on October 06, 2009, 11:04:05 pm

I might be in the same boat soon, how many hours above 70*F does it need to have in order to be cured?  I live in S.FL, and as we get into late summer here, it gets below 65* at night for a while, but the days are still plenty warm (94* with a heat index of 105* tomorrow). To be safe let it sit for 2-3 days or 3-4 or ?

Swamp

You will have no problem with it curing. I would say clamp up your bow in the morning, next morning start working it.  I have used urac in the middle of the winter with  just some  heat lights pointing at my jig and had no problems with in 24 hours.

Title: Re: heat curing Urac 185/heat treating bamboo
Post by: Swamp Bow on October 07, 2009, 12:08:53 am

Thanks.  That makes life easier.  Even in the 2-3 weeks of "cold winter weather", it usually gets above 70*.

Swamp

Title: Re: heat curing Urac 185/heat treating bamboo
Post by: Josh on October 07, 2009, 09:56:45 am

hey thanks for all the replies!   :)  Good luck on yours too Swamp!

Title: Re: heat curing Urac 185/heat treating bamboo
Post by: Grunt on October 07, 2009, 12:58:00 pm

Swamp, the urac will be happier if you take the glued up bow and sit it outside in the sun for some hours.. It has got to be 70' or warmer. Hot box at 160' for three hours and you are good to go.

Title: Re: heat curing Urac 185/heat treating bamboo
Post by: Swamp Bow on October 08, 2009, 10:10:46 am

Thanks Grunt.   I could probably stick it in a box spray painted black and hit 160!

Swamp