Newbie to heat treating - what did I do wrong?

[NTProf]

I have built numerous bows but have never heat-treated one before. So I decided to try heat-treating a red oak board bow that I made. After tillering it out I heated the belly over a burner on our stove, just enough to turn it dark. But it has taken another inch of string follow immediately after the heating process. Am I supposed to clamp it with some reflex before I heat it? Is it too late to reheat it and bend the limibs so they are straight?

[Pat B]

By heating the wood it shrinks and if not clamped it will draw towards the heated area, thus the string follow. You may be able to clamp it to a form with a little back set(not much), reheat it and let it rest for a few days before removing it from the form. I'm not sure if this will work but I would give it a try. Not much to loose if it doesn't work.

[NTProf]

Thanks PatB! I will give it a try. That is the nice thing about trying things out on red oak boards.

[eflanders]

Try using a torch or heat gun while the board is on a form.  Do not clamp it!  The wood gets elastic as it is heated and the clamps will leave permanent marks in the wood.  Once the wood has cooled to the touch, you can clamp if you think it will need to be.  You can reheat the wood several times if need be. 

The additional set may have been caused by stressing the bow to soon.  The wood has to rehydrate after heating and certain woods need more time than others.  I try to wait at least 24 hours as a starting point.

[Marc St Louis]

If you had it over a burner then the weight of its own limb would tend to drag it down a bit.  You can add some reflex but, as Pat said, I wouldn't add much

[crooketarrow]

    If I do toast my bow I do it when I get it to simi bow form. I've never used a form at that stage. I've also never toasted a bow that was tillered. But what PAT said about the wood shrinking toward the heat makes sence.