Toasted or toast belly frets

[DV IN MN]

So I heated the osage stave adding curved limbs to match the natural curve of the other end. Ended up with some pretty severe belly frets. I can try to super glue or sinew wrap them also. I assume the sinew wrap would save not sure on the SG. If I take it below the frets depth the recurves will then probably be working recurves. Probably 1/2 of depth would be left if I removed to get what looks to be below the depth of the fret. Any thoughts?

[DV IN MN]

SIDE VIEW

[superdav95]

Depending on your length and style of bow you may be able to get away with 1/2” thick recurves.  Lots of factors to consider.  Those look pretty deep and would suggest a moisture issue or too much concentrated heat.  Did you use steam or boil the recurves?  You may have had some excess moisture to cause these cracks or frets.  Sometimes with steam I’ve seen the rapid loss of moisture cause these sort of cracks.  Also another thing to consider is keeping to single grown ring on the belly wood at the tips to help prevent lifting of cracks.  Depending on the draw weight you are hoping for you may be fine with 1/2”.  If not you could also consider a belly lam to strengthen that area to withstand the force and hold its recurve shape.  For frets this big I would hesitate on ca glue and wrapping.  It’s hard to say with out more info but would lean more towards a lamination    Hope this helps.  Good luck

[PEARL DRUMS]

I believe its from trying to bend too thick of a piece with not enough heat. I would get down below them and re-bend it, add a lamination if it gets too thin. The wood wasn't hot enough to stretch as far as you intended. Thick wood bends are best suited to steam rather than dry heat. That's my .02 cents.

[DV IN MN]

Reason I did what I did was since the other end had a natural recurve on it. It was at slight floor tiller. Did this since couldn't start the tiller process until both ends were the same. used heat gun and put 10 lbs of weight hanging off the end and when it was hot enough that the weight pulled opposite limb to resting on the cull then I clamped it down.
Moister? it is a 30 year old piece that has been inside and pretty dry in MN this time of year. But maybe. 
This was the second heat app the first one did not have enough bend so applied heat again. Should have left well enough alone.
Trying for weight in the 60's @ 29" draw 64 in. TT. 

[Gordon]

What PD said, reduce thickness to remove the fractures and add a lamination if necessary. You can tiller a bow before making heat corrections. I do that all the time because it is much easier to bend wood when it is near final tillered dimensions.

[bjrogg]

I believe its from trying to bend too thick of a piece with not enough heat. I would get down below them and re-bend it, add a lamination if it gets too thin. The wood wasn't hot enough to stretch as far as you intended. Thick wood bends are best suited to steam rather than dry heat. That's my .02 cents.
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That’s what it looks like to me too.

I usually reduce to about 3/4” maybe 1” at most.

Like Pearl said for recurves I use steam. The thicker the longer. Usually about a hour. I also have everything I need waiting and ready when I pull it out of the steam.

For dry heat it I hold heat gun on area to correct until I can feel the wood gives up and it willingly goes where I want it to. You can feel it.

If it doesn’t want to go I don’t force it. I either put it back in the steam or hold the heat gun on it longer.

For recurves I also use a thin metal backing strip that helps hold grain down. A d shape cross section helps and also chasing a ring on belly side where recurves are going to be bent.

Bjrogg

[PEARL DRUMS]

Next time you need to bend some wood try to get it hot enough before you add weight and/or clamp it. By hanging 10# on it before hand you are asking it to start bending under that weight before it truly is ready.

[bradsmith2010]

what Pearl said

[DV IN MN]

Thanks for the info. I did rasp/sand to below the frets. It is now 1/2 deep by 7/8 wide at that point and we will see if it will work or if more compression damage is deeper than visible.

[Kidder]

Good save! These actually aren’t frets - they are tension breaks on the outside of the bent area due to using not enough heat and bending too thick of material (been there). Keep at it!

[Marc St Louis]

I've found that tension breaks like that while using dry heat is from trying to bend the wood after the wood has been heated up to bending temperature.

[superdav95]

I think your in good shape now. 

[bradsmith2010]

nice save,, it looked pretty bad,, 

[bjrogg]

I've found that tension breaks like that while using dry heat is from trying to bend the wood after the wood has been heated up to bending temperature.

That’s interesting Marc.

Now that you mention it. It kinda makes sense.

The heat would be bad for tension strength and it also makes the wood bend deeper. That would cause the deep cracks that go straight down.

I don’t usually bend very thick stuff if I don’t have to

Bjrogg