Primitive Archer

Main Discussion Area => Bows => Topic started by: Marc St Louis on January 07, 2015, 07:34:30 pm

Title: Lab test on heat-treating
Post by: Marc St Louis on January 07, 2015, 07:34:30 pm
An engineer in CA by the name of Richard Baugh has a keen interest in bows.  Richard convinced an engineering grad student to do some tests on Hickory versus heat-treated Hickory then sent me a copy of the test results.  I found it to be quite an interesting read.  I've uploaded a copy to my site and if you are interested can read it here, sorry but you'll have to fill in the blanks

       ironwoodbowyer.com/Heat-Treating___How_To_s.html
Title: Re: Lab test on heat-treating
Post by: bushboy on January 07, 2015, 07:52:55 pm
I'm thinking it has something to do with the sugars crystalline in the wood. Only a guess but i'm not good at word puzzles
Title: Re: Lab test on heat-treating
Post by: DC on January 07, 2015, 08:04:07 pm
Anyone else having trouble opening it. I get a network difficulty thing.
Title: Re: Lab test on heat-treating
Post by: SLIMBOB on January 07, 2015, 09:06:50 pm
Interesting read Marc. A bit over my head, but it appears to show scientific evidence that backs up what you first put forth, and what we all have seen in practical application. Thanks for posting it, as I enjoy reading this kind of data, even if I only comprehend it in bits and pieces.
Title: Re: Lab test on heat-treating
Post by: mwosborn on January 07, 2015, 09:15:20 pm
That is interesting - 26% is significant.
Title: Re: Lab test on heat-treating
Post by: Chadwick on January 07, 2015, 10:03:58 pm
As the heat treatment caused mass loss and significant tangential size change, I was wondering if this is a mostly mechanical/physical property difference, changing the wood density and/or hardness. Do you think that heat treating could have a similar influence as burnishing the wood?
Plus, this was either extremely dense hickory (.88 sg!) or it was mis-measured by the researcher.
In addition, to what degree is elasticity an issue for heat treating the belly of a bow? I wish the compression values were found.
Thanks for sharing!
Title: Re: Lab test on heat-treating
Post by: Josh Shuck on January 07, 2015, 10:29:22 pm
If you char an organic substance its a process called carbonization.  Materials that are carbonized become strong. That's how carbon fiber is made.

Primitive carbon fiber...I dig it!

Title: Re: Lab test on heat-treating
Post by: DC on January 07, 2015, 10:30:21 pm
Got it opened. Interesting read.  :D
Title: Re: Lab test on heat-treating
Post by: PatM on January 07, 2015, 10:51:21 pm
Can't open it here but you can read several in depth articles on what happens to various wood species when heat treated.
 It's far more complex than just drying and  melting sugars.
Title: Re: Lab test on heat-treating
Post by: Eric Garza on January 07, 2015, 11:41:53 pm
I would also have liked to have seen more of a focus on whether heat treating changes compression strength, although the other info was definitely interesting.
Title: Re: Lab test on heat-treating
Post by: bradsmith2010 on January 08, 2015, 07:56:04 pm
I got it loaded and ready to study,, thank you Marc
Title: Re: Lab test on heat-treating
Post by: Badger on January 08, 2015, 08:01:46 pm
  It did finally verify something that most of have found to be true. I feel like heat treating is the single most significant improvement to bows. Any style bow can benefit form it and most woods will benefit from it.
Title: Re: Lab test on heat-treating
Post by: carpholeo on January 08, 2015, 08:30:01 pm
All that being said, what is the proper method of heat treating?
Title: Re: Lab test on heat-treating
Post by: adb on January 08, 2015, 10:40:03 pm
TBB Vol 4. Marc spells it out, in detail.
Title: Re: Lab test on heat-treating
Post by: willie on January 08, 2015, 11:02:08 pm
can anyone report their results with heat treating birch?
Title: Re: Lab test on heat-treating
Post by: Marc St Louis on January 08, 2015, 11:20:20 pm
One thing to remember is that heat-treating will not increase the elasticity of a wood.  That is a given and inherent to each individual species of tree
Title: Re: Lab test on heat-treating
Post by: willie on January 14, 2015, 03:43:50 pm
the report about heat treating was helpful, but it's limited scope doesn't add much new info to help the bowyer 'zero in' on how to obtain the best benefits.

If one were to pursue some further testing, does anyone have any ideas about temperatures and cooking time to explore first?

60 times 60 tests has been sugggested, but that might take quite a while.