Elm back rings too thin?

[NicAzana]

Hi everyone

Now spring is here I'm tinkering with a few projects, trying to get a second bow done.

I'm roughing out this AFB Elm stave that comes from the same tree as a few other staves i split last year, which had very thin outer rings. Earlywood/Latewood ratio seems pretty good throughout.

Last year I roughed one of the other staves out, and started tillering it last week. I accidentally scorched the edge of the back a little in one spot, trying to heat correct, recurve and heat treat at the same time (lesson learned - don't try to do it all at the same time ). It raised a splinter in that spot during tillering, and I'm now mulling over whether I should try to save it with a backing.

However, that got me thinking that maybe these rings are too thin regardless, and though I've gone with a little more safe design for this stave, they might not be up for it. So I'm asking whether you think I need to either back it or work it down to a thicker back ring. I'm doing that know with some laburnum i have, and I would really rather avoid it with this elm. I have some nice cherry bark (it's definitely the right stuff) that i harvested last year that i could back it with.

What do you think?

The stave is roughed out to 1 3/4 '' limb width untill midlimb, then tapering to 1/2'' tips, and I'm aiming for 50-55 lb @ 28''. it is moderately crowned on the back.

Thank you for all the nice info on these forums, I hope to be able to actually post some results soon, instead of just stave questions:)

[Hrothgar]

IF you only violated an edge I would just apply some type of cloth material as a backing, I've used linen quite a bit with good results. Backing now might save a time and headache from trying to chase another ring. Let us know how it turns out.

[PatM]

Those rings are fine as long as you don't damage them.

[NicAzana]

Great!

PatM: I wasn't planning on it:) I was just worried, because those rings are only about 1/32" thick, and in TBB 1, I believe Paul Comstock writes that you should have at least 1/16" summer growth in the outer ring.

[Jim Davis]

You didn't need to  chase a ring at  all. Elm is ready to go  right under the bark.  Being ring porous, it doesn't matter how thick  the rings are, nor does it matter about early/late ratios. When the bark is gone,  the back  is done.

[BowEd]

+1.Also trying to bend it while too thick will bring splinters up too.

[bownarra]

The rings aren't a problem. No need to chase a thicker ring, although it would be easy on elm and when you noticed you had charred the back of your previous bow you could've chased the next ring down and removed the damaged /charred wood.
A wrap of sinew, linen soaked in epoxy etc is the quickest 'fix' for the raised splinter.