another weird problem

[radius]

Hey guys.

I recently bought some white ash, a plain sawn board 2" thick by 8' long.  I sawed the thing down to 68", and then ripped strips off the edges, which gives me quarter sawn strips.  This is edge or vertical grain wood. I have been using them to glue up a number of blanks, and now I am beginning to tiller these blanks into bows.

Today I experienced a strange problem, one which people would expect to find from stepped-down, plain sawn wood:  the backing strip cracked!  A little section of it lifted up in sort of a horseshoe shape.  I'd take a picture for you, but i recently moved and lost the cord which connects my camera to the computer. 

I've never had this trouble when using plainsawn strips as backing...but it has happened twice now:  both with edgegrain material. 


Any thoughts?

[tom sawyer]

Might have been a wiggle in the grain such that you aren't getting continuous fibers.  Even with quartersawn stuff, you have to have the strips following the grain.  Its tougher to tell with quartersawn strips too, since you are going off the skinny side to tell how things are running.

That, or the ash might be somewhat brittle from kilning.

Those are the two I can think of.

[JackCrafty]

If you have scrap that is long enough (when you cut the staves down from 96" to 68"), try ripping the scrap into strips and then break the strips.  If the strips seem to break too easily, you might have a brittle board of ash.  If the strips seem strong, then there is a defect in the strip that failed.

The problem seems normal enough to me....ash is not a wood I would recommend for backing strips anyway.

[knightd]

was the blank in a hot box? If so it could be to dry..

[radius]

no hotbox...

and as for ash being a poor choice as a backing strip, i just remember reading that any wood which will make a selfbow will make a backing strip..no?

[mullet]

  I don't do a lot of board bows , but, when I do I try to use a wood like hickory or something similer with interlocking grain. Just in case of getting a piece with a defect.

[Ryano]

I saw all my backing strips out of staves for the most part. Its a guessing game when your using a edge grain board from a saw mill. There are way better choices out there for backings than ash. Most people back ash with sinew or something. Its not the same as hickory.

[Badger]

  1/4 sawn backing strips are pretty bulletproof if they don't have grain run outs and they are the right species of wood. Ash is probably the most inconsistent wood there is for both density and elasticity. Some ash van be very strong and dense while others can be light and useless. I think english swamp ash or water ash is listed as one of the most elastic of all woods. If I find a heavy piece of ash I don't hesitate to saw it up into backing strips if there are no grain run outs. As long as the grain runs straight down the back of the bow most backing strips are fine 1/4 sawn, if they run off the side they are almost sure to break. Steve

[JackCrafty]

Radius, any wood can be made into a self bow.....including woods like willow, pine, and poplar.  But these woods are poor choices for backing strips.

A backing strip should be similar in weight (specific gravity) to the core wood but much better in tension strength.  I don't back my bows (and I'm no expert) but if I was going to back a light wood bow I would use elm.  On a medium weight wood, I would use hickory and on a heavy wood I would use bamboo.

[koan]

I recently made a reflex/deflex from ash and it hammers an arrow, but it took a ton of set for no apperant reason. Way understressed design @28" for a 68" bow..good luck Bro, I cant figure it out either .....Brian

[radius]

thanks guys

[sailordad]

well i thought i read that ash was a decent,not great,bow wood.
after reading this i dont think that i'll go limb out the neighbors ash tree in the middle of the night. however i did spot a lilac bush/tree that had several
main trunkd that were relatively straight and about 5" in diameter. that might not be as safe.

[knightd]

Any time you back a bow you could have it pop a splinter or such. It just happens.
  Sailordad.. Ash in the right design can be a very light and fast bow.

 David

[sailordad]

so i should still plan on limbing out my neighbors tree some nigh then

[Ryano]

Ash can be decent bow wood, but I wouldn't risk ticking off a neighbor or possibly going to jail for it.
I have access to pretty much unlimited amounts of straight as a arrow ash trees but I don't even bother with it when I have access to woods like Elm, hop hornbeam, black locust, hickory, hard maple and wild apple. Oh, and now add to the list hawthorne.