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Author Topic: When to heat treat to hit target weight.  (Read 1588 times)

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Offline JWMALONE

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When to heat treat to hit target weight.
« on: January 23, 2018, 07:30:45 am »
Hello guys, been reading other post but haven't found the info I'm looking for. Lets say ive got a hickory bow I want to come out at #60. Should I tiller it to 55 then heat treat or tiller to 60 then heat treat? If the heat adds weight I don't want it to end up 65-70 pounds. I'm wondering if I should hold off on heat until its shot in and all the final tweaks and scraping are done incase I drop some weight getting the tiller fine tuned. But don't now if the heat will change tiller. Ive read you can heat treat multiple times. How do you guys allow for that?
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Offline Pat B

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Re: When to heat treat to hit target weight.
« Reply #1 on: January 23, 2018, 08:20:55 am »
John, tiller your bow to the ultimate draw weight .  If by heat treating you go over, reduce the weight to your desired weight. Heat treating isn't just a surface additive, it should go deeper to be effective.
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Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline bjrogg

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Re: When to heat treat to hit target weight.
« Reply #2 on: January 23, 2018, 08:24:42 am »
Interesting question JW, I usually heat at about where I'm at first brace. I usually try to get everything as straight and untwisted as I can on caul. Then I finish tiller it. I may or may not heat again. Usually if I don't need a correction and haven't taken to much off since heat treat I just leave it.

Heat treatment is different than just heating and straightening. It usually take me about 45 minutes a limb for heat treat but it's a good time to get everything going in the right direction.

It'll be interesting to see what everyone does.
Bjrogg
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Offline Del the cat

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Re: When to heat treat to hit target weight.
« Reply #3 on: January 23, 2018, 08:36:59 am »
It's the old mantra, it's easier to take wood off than to put it on.
I'd suggest heat treating when it's nearly at target weight/draw and before the final finishing stage, or when it's at say at 20" draw..
No point doing a load of finishing and then having to sand the surface again.
Also no point rasping off wood that you've carefully heat treated, but have done it too early!
I'm currently working on a Hazel primitive, I made a weak point into one limb (totally intentional of course  ::) ), by the time I'd got the tiller even I was going to be a tad under weight... so I heat treated it and will just about make target weight.
Del
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Offline DC

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Re: When to heat treat to hit target weight.
« Reply #4 on: January 23, 2018, 11:37:47 am »
I've noticed that if I treat it too early I seem to remove most of the treated wood. I wait until I'm out to about 20" or so, maybe further. One of the advantages of heat treat is that it make the bow stronger so that you can remove more wood. Removing wood make the limb lighter and that's a good thing.
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Offline JWMALONE

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Re: When to heat treat to hit target weight.
« Reply #5 on: January 23, 2018, 11:48:49 am »
Thanks Guys, I just want to do everything I can to make this bow one that will be dependable no matter what. The thing that makes a bow beautiful in my eyes is knowing I can pick it up day or night and it will do what its designed to do. Unlike some bows that ya bump it on a limb and your watchamcallit is out of sync with the thingajiggy  and then it don't shoot right no more. LOL
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Offline Parnell

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Re: When to heat treat to hit target weight.
« Reply #6 on: January 23, 2018, 12:12:40 pm »
The advice at heat treating mid tiller is on the mark.  Remember, you are pre-compressing wood cells on the belly by treating.  Like smoking meat...slow and steady - you want to have a deep treatment.  Darken the wood to almost the point of being black but careful you don't start an ember, or else.  I'd really recommend allowing the wood to rehydrate a bit before tillering. 

I wonder if treated low moisture whitewood has a greater tendency to chrysal - fret.  Especially if it's during the low humidity winter in the cold states?
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Offline Pat B

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Re: When to heat treat to hit target weight.
« Reply #7 on: January 23, 2018, 01:22:07 pm »
Steve, no matter when you heat treat you still have to let it rehydrate before stressing it.
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Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Mo_coon-catcher

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Re: When to heat treat to hit target weight.
« Reply #8 on: January 23, 2018, 03:05:09 pm »
I usually heat treat once I get it braced and the profile evened out. It seems like once you’ve heat treated correctly. You can scrape off a good bit of wood and maintain the benefits of the heat treat. Just go nice and slow so you can feel the heat come through to the back. Then I bring the gun closer to the belly and get a light scorch. I usually use black locust, and after the initial heat treat, I’ve done a second once I had yhebtiller about done. But I saw no difference after the first heat treat. And set I would heat out would be right back within a couple pulls and the weight wouldn’t shift any.  With locust I like to do the heat treat as early as I can when I know the limbs are balanced. That way I can keep any set and chances of frets to a minimum while tillering. And I just carry that habit to other woods too.

Kyle
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Offline burchett.donald

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Re: When to heat treat to hit target weight.
« Reply #9 on: January 23, 2018, 03:23:11 pm »
  +1 on Mo-coon-catcher,
                                       I like to heat treat at floor tiller or right at brace...Set can happen early in a build...Sometimes one more treatment on white woods near final tiller and limb alignment tweaking...
                                                                                                                                  Don
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Offline willie

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Re: When to heat treat to hit target weight.
« Reply #10 on: January 23, 2018, 03:31:41 pm »
switch to side tillering after heat treating?
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