Do I continue as-is?/Did I make a ticking time bomb?

[Fox]

Although i am inexperienced.. i have seen those kinds of cracks happen when recurving and it ussually seemed to happen when it didnt get steamed properly..

-Fox

[Pat B]

Unless you put a radical, isolated bend in the limb or unless the wood is rotten it shouldn't have cracked in tension.
The discoloration is normal in locust from my experience unless the locust is infested in rot. You should be able to tell if it is rot if it is softer than the surrounding wood.

[Likemp]

DC/Fox - Steamed it over a large shallow pot on the stove, wrapped in a washcloth, covered in tinfoil, rolling boil probably for an hour. Then, right to the clamps in the shop for 24hr and then into the house. 

Bassman - Thanks for the support, I'm really enjoying this process. The fact that every failure I've had so far directly translates into a new bit of first-hand knowledge I can use is pretty satisfying in it's own way, but it can be frustrating wanting to move quickly.  I'm lucky that I have access to the little bit of wood that I do for rounds 2, and 3, and 4... If I was trying to source staves from somewhere or buy them that would be a different story.

Pat - I don't think the bend was too radical, I feel like I've been guilty of not going far enough out of lack of confidence. The fact that I lost most of the reflex after bringing it inside and before bending it makes me feel I did the same here. The texture of the off-colored wood is no different than whats surrounding it, it's actually quite attractive in my opinion.

[DC]

DC/Fox - Steamed it over a large shallow pot on the stove, wrapped in a washcloth, covered in tinfoil, rolling boil probably for an hour. Then, right to the clamps in the shop for 24hr and then into the house. 

So you wrapped it in a rag, wrapped tin foil around it and suspended that bundle over a pot of boiling water?? If so the wood never even got warm, not through all that insulation. Maybe I'm misunderstanding.

[Likemp]

No problem! I wrapped the limb in a rag so the belly wasn't resting directly on the hot edges of the pot when I laid it across, then I covered the pot in foil with the rag-wrapped limb under the foil. Much like most of the pics I've seen on here.

[DC]

So the wood was exposed to the steam?

[Likemp]

Very much so, for about an hour.

[DC]

OK that's all I've got

[Pat B]

Do you have a heat gun? For reflexing, dry heat works well with black locust and you can temper the belly to black to help increase it's resistance to taking set and fretting.

[Weylin]

I agree with Bushboy. Those are tension cracks on the belly from when you added reflex. If you keep bending the bow with them still there they will start to collapse under compression and act like frets though.

[scp]

My first thought after looking at the picture was tension fracture, just as many people here said. One hour of steaming might have made the unseasoned belly suddenly too dry and when reflexed it just gave out eventually. That would explain the loss of reflex immediate upon un-clamping. I would forget about reflexing the limb and just deeply heat treat the belly and apply crazy clue or epoxy after it cools down. Good luck. I also would probably go for much lower draw weight.

[Likemp]

SCP - Thanks very much for your input, you just answered a lot of my additional questions. You think a shorter steaming session have left me without the fractures? I wasn't shooting for an hour, just erring on the side of "more-couldn't-hurt" and may have forgot about it while working . The wood is definitely not fully cured, but I had steamed/heated a rough bow I made from the same tree before and didn't have a problem so that may have given me some unwarranted confidence  .

[scp]

Do you remember which side, back or belly, was facing the steam? Unlike boiling in water, it might matter which side gets more steam and higher temperature. "Plastic[ized] wood can be compressed by up to 25-30 % but stretched by only 1-2 %. (This is why heating the inside of the curve is most important.)" This is somewhat counter-intuitive. I guess we cannot steam the belly too much, compared to the back, in reflexing the limbs.

Same goes with the dry heat bending. But in bow making, we cannot apply dry heat to the back too much because doing so might make the back too brittle, unless we are just making static recurve tips. Still counter-intuitive. I never apply dry heat to the back, even at tips.

[Likemp]

Pat B/Weylin - Thank you guys for chiming in as well! I do have a heat gun, would a deep tempering help the cracks better handle compression and keep them from turning into frets? or would any heat at this point make it worse?

scp - I made sure to do it belly side down. Everything I've read has been very clear on being careful to not heat the back too much, but are you saying for reflex maybe do back side down and for less time?

[scp]

I have a bad habit of leaving the bow tip belly up on the form and steam it while letting the weight of the bow itself bend in the static recurve. I used to steam it from above, on the belly. Doing it that way I did get the tension fracture on the belly a couple of times over the years. Now, I steam the back of tip through a hole in the form.

Many people are saying that the tip bending should be done at once after the bow tip is boiled or steamed fully, but not too much. I think the bending should be watched carefully especially if we are not using a metal strap to protect the belly. We also should not steam the tip too long. It would take less than 15 minutes of steaming to make the thin tip pliable.

Reflexing the limb, not just the tip, using steam on the back might be a different story. I doubt steaming the back would harm the bow as much as using dry heat. But I just use the deep dry heat treatment on the belly to reflex any part of the limb other than the tip.