Question for elm gurus

[Ink]

Got a stave I'm getting ready to resaw. It's slippery elm and 4" wide by 2" thick. I have no plans for it yet, just trying to get it drying. Anyways on a basic longbow about 50-55#, how wide does a heat treated piece of slippery elm generally need to be at its widest? Say a pyramid to make it easy. Just curious if I can get away with sawing this thing in half or just keeping it as is?

[Pat B]

Ink, is this a tree stave or board stave? My only experience with elm is a 60" static recurve from a tree stave. I was very impressed with elm after building this bow.  You can see the build along in the "How TO" section.
 Elm was one of the traditional ELB wood I believe.  1 1/4" to 1 1/2" at the handle would be traditional also I believe. I would heat treat the belly. It served me well for the 60" static recurve.

[Ink]

It's a tree stave. Was wanting to cut it into 2x2" as long as I won't screw myself by getting greedy. I'm gonna look at that " how to" as soon as I get done writing this.

[Pat B]

2x2 should be plenty.

[Marc St Louis]

It really depends on the wood but I've never found the need to go over 1 3/4" wide for a flatbow and if the wood is elastic then even more narrow than that.  If what you want to build is an ELB then you won't need much more than 1 1/4" in width for a 50# bow and the same for an ALB.  That said you should be able to cut your stave in half, as long as it's not a split/sawn wedge from a small diameter tree.

[Ink]

Marc - it's a quartered piece out of a 12" tree so it'll probably be good to cut in half then. Generally I'm an osage guy, but this elm is started to grow on me. Sure is nice not to have the wife screaming at me not to touch her cause my hands are stained black . Thanks for the replies Pat and Marc.

[4dog]

didnt hurt that it was just laying there waiting to be hauled out by two bow building maniacs with nothing better to do than break their backs shouldering that monster out over about 200 other trees....coulda broke a leg!

[Ink]

It wasn't that bad. A good log is worth a broken leg, as long as it ain't mine  . But that's not the log I'm cutting anyways. The big one that we all keep tripping over at the front of the garage was the one I was cutting into staves. The winged elm log was only about a 6"

[4dog]

lol   i was too burdened by the log to check the OD!!!  glad your moving that trip monster though!!

[ohma2]

I realy like tht elms watch your tillering though, it tends to crysal if your not carefull.

[Marc St Louis]

I realy like tht elms watch your tillering though, it tends to crysal if your not carefull.

If the Elm you are using chrysals that easily then it is not very high quality.  High quality, elastic Elm will take a lot of stress without chrysalling. 

[4dog]

any easy way to know the "quality" of the elm before ya use it??

[Marc St Louis]

any easy way to know the "quality" of the elm before ya use it??

If there is then I haven't discovered it....yet.  I do know that some Elm can have a variation in ring thickness' even along one growth ring.  I have seen rings barely 1/8" thick at one point of a stave and further along that same ring can be 1/4" thick, that doesn't mean it is poor wood though.  I tend to prefer Elm that has fairly uniform growth rings, rings that are pretty well the same across the trunk, and uniform ring thickness along the stave and the rings should be at least 1/8" thick.  That is still no guarantee that the wood will be good but in my experience it's more likely that it will be.  I have had fairly good results with Elm that have fairly thick growth rings, 1/4" and more.  Those Elm are usually less dense than thinner ringed wood but they are more often than not more elastic.  The best way though is testing.  Make a bow with a stave from the tree and stress it...hard.

Here's an example of Elm that is very elastic, a bit low in density but good wood none the less.  The bow is 55" long and tillered to 28", you can see in the picture that is highly stressed, the other pic is a close up of the rings.  The rings are very uniform and for the most part about 3/16" thick.

[4dog]

thanks for that info...very helpful!!

[Marc St Louis]

You are welcome. 

Another thing I have noticed and this part is more by feel and sound rather than how the wood looks.  Some Elm have wood with a texture that is, for lack of a better word to use, crispy.  When you rasp it the wood comes off in fine dust, so to speak, as compared to other Elm type.  There's an example of this type of wood in the "Build Along" forum titled short 52" bow, or something like that.  Usually this type of Elm has a lot of heartwood and very little sapwood.  This wood is lower in elasticity and more prone to chrysal than other types of Elm.  Elastic Elm has wood that is smoother, again for lack of a better word.  When you rasp this type of Elm the wood comes off in much larger chips and the texture of the wood is not brittle.  Sorry but this delves more into the feel of the wood and is about as good an explanation of this as I can give.