Elm recurve

[simk]

exactly: it's a function of time and temp. and white woods are different than non whites... e.g. I would never charcoal osage. but we are coming near off topic 

[willie]

is it that the heat changes the properties of lignin and hemicellulose to cause them to be more advantageous to compression or possibly reduce how much moisture the wood holds?

maybe some of both. It has been demonstrated that heat treated wood is less able to reuptake moisture. Hetatreated wood is marketed in europe widely as a preservative treatment alternative to cca (anti fungal).

it seems properly heatreated wood cannot get wet enough to support rot. I don't know if it can be used below grade in wet locations or is a substitute for what we call "above ground" applications.

[bownarra]

Just to clarify I wasn't meaning charcoal black.... or smoke...   Dark brown is proabably more correct. I was really meaning on the well done side of dark brown to make sure corrections/set removals hold.

[bownarra]

Hopefully I should get some time to myself to get this bow finished today, I'm interested to see what the chrono says. The string tension so far is unreal, like a hornbow Obviously it will lose some of that but lets hope not too much.

[Marc St Louis]

Yes string tension on these types of bows is pretty high

[bownarra]

Well you win some you lose some....got her to full draw and heard the dreaded 'tick'. Inspected it throughly and finally found a little tension break on the back. It has only just gone on the surface fibers so I could rasp some off the back then sinew it. It is probably worth doing as the few shots I had at 24" or so were smokin'.....It held 4 1/2" inches of the 7" I put in it so not bad. At least sinew would make it completely tension safe.

[RyanY]

Well you win some you lose some....got her to full draw and heard the dreaded 'tick'. Inspected it throughly and finally found a little tension break on the back. It has only just gone on the surface fibers so I could rasp some off the back then sinew it. It is probably worth doing as the few shots I had at 24" or so were smokin'.....It held 4 1/2" inches of the 7" I put in it so not bad. At least sinew would make it completely tension safe.

That’s a shame. Hopefully it can be saved.

[HH~]

Wow
Never had tension back problem with Elm. Never worked 10yr old billets either. I bet with elm it’ll sinew very well. Wonder if to much heat on old elm or the reflex contributed to this?

Shawn

[bownarra]

Yes i'm fairly certain the heat/reflexing contributed. It was at a spot where the heat had crept onto the side of the limb....
Nevermind I will find some more wood and give her another crack

[HH~]

Got a picture for review??

Shawn~

[Marc St Louis]

If your wood has thin rings then that can be problematic for the back. 

All of the best Elm I ever cut had uniform rings, although this did not necessarily hold true throughout.  Some trees that I cut had rings that varied from thin at one point to thick further down the tree.  This was usually still good wood just not as good as trees with uniform rings.  I never knew if the wood I cut was very good wood or just good until I made a bow with it, sometime it would even turn out to be crap wood.  The conclusion I came to years ago is that not all Elm are equal and the good ones are few and far between, unlike HHB where it is rare for a tree to be poor bow-wood

[Digital Caveman]

I find this interesting because right now I am working on an elm bow with limbs that taper from about .8" to .75" and it is already underweight.  It is 69" ntn with a 10" riser and is 1 5/8" wide for the first 6".  It is more bendy than a 55# HHB bow I have.   2 other staves I've worked from this tree where also quite whippy.  I am having a really hard time getting the mass down because of such thick limbs.

I hope this isn't to far off topic.

[bownarra]

Here are a few photos just before the break.

[HH~]

Looks like your left hook was working a bit (small). Had tip overlays on it.  Flattened out like most unbraced recurves will but that depends on the quality or the piece of wood. Was looking good too. Never had an Elm stave have a back fail even after crazy heat and putting rather big sweeping static hooks in them. They were beefy bows however and I was never chasing speed.

Shawn~

[Allyn T]

Did most of the reflex pull out?