Primitive Archer

Main Discussion Area => Bows => Topic started by: J05H on June 21, 2014, 09:09:57 am

Title: How long to wait after dry heat?
Post by: J05H on June 21, 2014, 09:09:57 am
Hey guys, I just finished straightening a bow blank so the tips allign using dry heat. I was wondering how soon I can start on tillering. I don't have a lot of experience with heat corrections. Just in case its relevant, the bow blank is red elm and the heat correction was confined to the handle.

Thanks in advance, Josh
Title: Re: How long to wait after dry heat?
Post by: NeolithicMan on June 21, 2014, 09:14:30 am
I have heard/read a few different beliefs on this. Between let it sit until RH raises the MC back up, and just wait until its cooled down. I feel it depends on the wood really, hickory i like to wait, osage i give it 1-3 hours to cool down and get back to it. just did that last night with osage and the string alignment did not change so i think im good
Title: Re: How long to wait after dry heat?
Post by: SLIMBOB on June 21, 2014, 09:36:14 am
If I heated the working part of the limb, I will wait a day before working it too hard just as a precaution. The handle, if it's non working, I'd let it cool and carry on. Working handle, I'd wait a day just to be safe. One of my cauls is made from Cedar. When I use it, the resins boil at the surface. Some moisture displacement is happening in the wood, so I play it safe by giving it a day to recover.
Title: Re: How long to wait after dry heat?
Post by: J05H on June 21, 2014, 09:41:30 am
Thanks guys. I appreciate the info. I think I'll get started as soon as it cools.
Title: Re: How long to wait after dry heat?
Post by: Pat B on June 21, 2014, 09:48:31 am
For heat straightening I try to wait until tomorrow before stressing the bow. For heat tempering I give it 3 or 4 days to rehydrate before stressing the bow.
Title: Re: How long to wait after dry heat?
Post by: bubby on June 21, 2014, 01:21:05 pm
For heat straightening I try to wait until tomorrow before stressing the bow. For heat tempering I give it 3 or 4 days to rehydrate before stressing the bow.


x2
Title: Re: How long to wait after dry heat?
Post by: DuBois on June 21, 2014, 01:53:10 pm
For heat straightening I try to wait until tomorrow before stressing the bow. For heat tempering I give it 3 or 4 days to rehydrate before stressing the bow.
Hey Pat, why different times for these 2 things? I'm sure there's a reason and I want to understand.
Thanks, Marco
Title: Re: How long to wait after dry heat?
Post by: Pat B on June 21, 2014, 02:10:15 pm
Marco, when I'm bending or straightening I heat the wood just enough to bend it. This dries the wood out but not much.  When tempering a belly I deep heat the wood, scorching the surface. This dehydrated the wood pretty good and if stressed too soon before it has time to rehydrate it can cause a failure. Most woods need to be about 9%-11% for bow building(hickory 6%) or they can fail in tension because the wood is too dry(brittle).
Title: Re: How long to wait after dry heat?
Post by: DuBois on June 21, 2014, 02:21:13 pm
OK, thanks Pat