Primitive Archer

Main Discussion Area => Bows => Topic started by: johnminnitt on July 27, 2018, 09:07:48 am

Title: Marks in Sapwood
Post by: johnminnitt on July 27, 2018, 09:07:48 am
I'm sorry to bother people again, but, continuing with the ELB I posted about a little while ago, in getting rid of the cambium and thinning sapwood a bit I find something I don't think I've seen before in yew - fine black lines in the sapwood, I hoped they were just on the surface but they run down at least through the 3 layers I have removed so far.
I'll try and add a picture or two, though ut was hard to get them to show up.
Any views on what they are, and what to do (if it's not completely fatal) will be welcome.
Title: Re: Marks in Sapwood
Post by: Del the cat on July 27, 2018, 09:19:17 am
Hmmm, could be rot... the wood will let you know  :o >:D
Del
Title: Re: Marks in Sapwood
Post by: johnminnitt on July 27, 2018, 09:43:22 am
I wondered that, though the wood feels sound.
Title: Re: Marks in Sapwood
Post by: PEARL DRUMS on July 27, 2018, 09:47:15 am
Looks like spalting, and rot is basically what that it is. A slow, controlled rot. I say taker her down to heartwood and add sinew.
Title: Re: Marks in Sapwood
Post by: Pat B on July 27, 2018, 10:35:01 am
That is fungus. Get down below it and see what the heartwood looks like. I wouldn't use that as it is.
Title: Re: Marks in Sapwood
Post by: johnminnitt on July 27, 2018, 10:42:51 am
Thanks all.
Unfortunately it seems to run through most of the sapwood, and there's not enough heartwood to remove all the sap. At the tips there would only have been a thin heartwood layer.
Well, it was quite cheap for a full-length yew stave (being knotty, which I'm quite happy to deal with). A bit expensive for 7ft of firewood though!

Title: Re: Marks in Sapwood
Post by: PEARL DRUMS on July 27, 2018, 11:17:27 am
Id still add sinew to it then and hopefully shift the shear force away from the sapwood as much as you can. It very well could make a fine bow.
Title: Re: Marks in Sapwood
Post by: johnminnitt on July 27, 2018, 11:30:09 am
Sinew on an ELB seems a bit inappropriate?
I wonder if a rawhide backing would be worthwhile?
Title: Re: Marks in Sapwood
Post by: PEARL DRUMS on July 27, 2018, 11:40:33 am
No more inappropriate than tossing it in the trash? A bow is a bow is a bow. Rawhide may hold it together enough to keep you from getting hurt when/if it blows up, but I don't think it would hold together like sinew would.
Title: Re: Marks in Sapwood
Post by: Del the cat on July 28, 2018, 01:08:19 am
You can just treat it as a learning exercise, but just don't be surprised if it does blow on the tiller.
Working round the knots etc will be good practice.
Better to practice screwing up on a poor stave than a good one... >:D
Del
Title: Re: Marks in Sapwood
Post by: johnminnitt on July 28, 2018, 04:10:30 am
Thanks again for all advice/suggestions.
Irrational I know, but I don't feel right about sinew (seems expensive too), and I would like to try and get a bow out of it rather than press ahead with likelihood of that horrid breaking noise on the tiller.
So I'll probably set it aside to mull over while I work on my other (and better) stave, then very likely plane off most of the sapwood and put on a back of hickory or possibly ash, so any remaining affected sapwood will be essentially a core and so less stressed.
Title: Re: Marks in Sapwood
Post by: Eric Krewson on July 28, 2018, 06:58:54 am
I made a bunch of spalted wood gizmos to donate, the wood had hard and soft spots in it, some very soft. The only way I could get a gizmo out of the wood that wouldn't break easily was to soak the wood in superglue.  I was surprised just how much glue the soft spots in this wood would absorb, the wood was like a sponge.

You have nothing to lose, see if your wood will absorb superglue.
Title: Re: Marks in Sapwood
Post by: Marc St Louis on July 28, 2018, 07:16:45 am
That doesn't look good.  I would be inclined to try and put a hard backing on the stave