Slyngorm wrote on Feb 19
th, 2021 at 5:18am:
I strung it, fired some grill spears and left it strung for the night. Next morning I strung a tighter string but when I pulled in it too much it snapped (not around the handle though).
You never, ever, leave a bow strung if you aren't shooting with it, not even the nice, professionally made ones. The wood gets permanently bent and they loose their power really, really quickly, in a matter of hours if you work with living wood bows we all made as kids. Or so I persume.
The breakage was proabbly a combination of factors, maybe the grains weren't straight, plus leaving it strung over night as it dried out - see below for that.
Slyngorm wrote on Feb 19
th, 2021 at 5:18am:
In the first video he heat treats the bow before stringing it. What difference does this make and is it necessary?
Pretty necessary in this circumstance, not at all otherwise. See below.
Slyngorm wrote on Feb 19
th, 2021 at 5:18am:
How long can you wait before working on a piece of wood that you have just cut down? Is something like 24 hours acceptable?
Right, so the principal issue here is that the living wood contains a lot of water - you can see that if you try to burn it, you get steam and bubbles on the surface. As the stick gets older and older after you cut it, the water dries out, and this process slightly warps the wood and generally changes how it behaves.
For any sort of permanent construction, bows included, the waiting time is about a year. Yup. You should also cover the ends of the stick with glue or some other stuff that prevents it from drying unevenly.
What you see in that first video, however, is the survivalist bow - you end up out in the woods and need to shoot a deer today, what do you do? Well, you use fire to dry it, which will get you an inferior bow to one you'd get if you waited a year, but you will manage to not starve.
This sort of bow is more prone to warping over time and probably breaking as well, but that's not really a mark against it - it's supposed to be an improvised hunting weapon, quick to make and replace if need be.