Fire hardening a board bow

[yote20]

Hey all,

First time posting.  Been dabbling for a while now but only with boards.  I've broken them all but one.  The surviving one came in under weight.  My question is can a bow from a board be fire hardened? That might be a dumb question.  I'm just wondering because most of the fire hardening info I see is in regards to staves. The bow is a 70" red oak pyramid style. Drawing 40lbs at 29". Would shortening the bow be a better option? The limbs are 2 inches wide till mid limb and then fading to half inch nocks. Thanks for the help!

Aaron

[KenH]

I assume (you don't say) that you want to increase the draw weight.  By how much?  Piking by an inch off each end should give you +5 or a bit more pound draw increase; but fire hardening wood (as distinct from bamboo) won't give you anything near that IMHO.

[yote20]

Thanks Ken. Sorry I did not mention that before. Yes. I am trying to raise the draw weight I'd also like to remove some of the set. I thought that maybe by fire hardening that would take care of both. I also forgot to add that the bow is also linen backed so I'm concerned that fire hardening would affect that also. But that's all a part of learning.

[Pat B]

My first question is why and how did your other board bows break? To answer your question yes, fire hardening and shortening a bow will increase draw weight.
 The best way to achieve draw weight is to never go over the intended draw weight while tillering.

[Longcruise]

Somewhat of a tangent to your question but from your description of the bow it isn't a pyramid.  Not saying that's a bad thing.

We're all of your broken bows also red oak and did they have the same profile?

Just thinking that maybe you should call this bow a success and duplicate it at a higher draw weight.

[yote20]

Pat: I would chalk them up to being impatient. Rushing through tillering process. I did the same thing here and got heavy handed with removing wood before tillering. I think I got lucky because I put a backing on this one.

Longcruise: Yes I would agree now that you point it out. Yes, they have all been red oak. Haven't been able to find anything with suitable grain in another species like hickory or maple. You're probably right I can call this a success since it is drawable. The state minimum to hunt with is 40 lbs of draw weight so I guess it is useable. Guess I was just looking to see if I could improve it a little.

[Pat B]

Patience is the best tool for wood bow building and finding the right board with the right grain is way up there too. Keep trying with a little more patience. You'll be amazed how effective it can be. 

[Honest Jon]

I’d be very cautious about fire-treating a board bow because of the effect on the glue between the backing and limb. And with a linen backing already applied I think I’d flat not even try it. Perhaps I’m misunderstanding that you are considering trying to salvage the bow already made with fire-treating.

Just to make you feel better, I probably batted .600 in even getting a board bow to finish tiller without breaking for my first 15-20 board bows. In time, probably half those finished bows broke in the first year of shooting.  Very discouraging! With experience came more patience and a switch to hickory self bows that I cut in my woods in May and built the following winter. I still build a loser once in awhile but have yet to break a hickory selfbow.
Honest Jon

[yote20]

Thanks Honest Jon. I did try to fire harden it 2 days ago. It ended up breaking. I had another board lying around so I'm working on it now. Definitely making sure I am patient with this one. Its not as wide though. Only 1 1/4 inch. Probably not a good idea but what do I have to lose besides time and wood. Learn something with each one I suppose. I'll let you know what happens with this one.

[Honest Jon]

Like many things in life…we often learn more from our failures than from our successes.
Jon

[Powder]

New here,but not new to board bows. 

To answer your question, YES, you can fireharden a board bow.

However, the problem is most likely not that you are not fire-hardening, but a poor tiller or poor choice of board. I say that based upon your earlier statements, and how I had to beat myself to death to figure it out.

There is a fellow on-line who runs a page called Meadowlark Adventure Gear. His content can be dry, but his builds are first rate, and he absolutley LOVES hickory, and also bamboo.

He also tends to steam bend his hickory in the middle into deflex, then glue on a backing, flip the tips, and builds some first class bows. I highly recommend you look up his channel and watch those videos. He is an absolute wealth of information, and he improved my builds quite a bit.

Red oak can make a decent bow. But heat treating, fire-hardening, works REALLY well with Hickory.

Ringingrocksarchery.com sells hickory boards, and they are usually pretty nice. It's the best source I have found for hickory on-line.

The attached pic is my most recent build, it is hickory backed hickory with an American Chesnut middle lam. I heat treat the belly with a box jig and a heat gun before glue up. The riser is twelve inches long, and it pulls 64 lbs at my 29 inch draw.

[yote20]

Did you make this with hand tools? That's pretty all I have except a belt sander and circular saw. I've broken 2 more since this original post. I'm using a tillering gizmo so I don't know what the issue is.

[Powder]

I use a rasp. circular or band saw, scraper, planer, and sander (belt and palm). All my tril-lams spend some time in the planer, but you can buy pre-planed wood from sources, or bite the bullet and get a planer. My was second hand and a little beat up, but it works.