I am working on a hickory backed massaranduba bow, 60" ntn, 1 1/8th inch at fades tapering to 3/8 inch tips. My hickory backing was about 1/8th inch thick maybe a little less. I had it pulling 21 inches at 30 pounds when the hickory began to develop small splinters. If I make the hickory thicker (maybe closer to 3/16 or 1/4 do you think that would keep the hickory from splintering? I don't think this thickness would overpower the massa either as it is pretty dense. Also the hickory has extremely straight grain, no runoffs
Can you post some pics of the splinters. That will help. 1/8th" should be just about right, though I am no expert and just starting my backing career.
I'll try to post pics when I get home from work. Just a couple small splinters on the center of the back about 6 inches from the fade of one limb. They would have definitely caused a problem if pushed further though. I know it could be due to the tiller but the tiller was looking pretty good up to that point.
Thickness doesn't matter as much as grain runout. .. that's grain runout, not growth ring runout. I've used hickory less than 1/16" thick without issue.
Even though the growth rings may be perfectly parallel on a quartersawn backing strip, the grain may have enough runout to cause a splinter to lift when flexed.
I tested the strip before glueing it on and it flexed really well without much strain (much further than the bow would bend at full draw) so it almost seems that the massa is overpowering the hickory of that's possible