80" White Elm Warbow Build-along

[Cameroo]

I'm just at the tillering stage on what will be, if successful, my first 100+ lb bow, and also, potentially my first successful selfbow.  I thought getting a little feedback along the way might improve my odds.  The stave is 80", and I am going to be shooting for 110 lbs @ 32". It is roughed out with shallow radius on the back edges, and deeper radius on the belly edges.  Threw it on the tree and it is just starting to bend a bit.

Measurements as it stands now (taken from center, proceeding outward at 6" intervals):

           Width   Thickness

center   1.57"   1.41"
+6"      1.49"   1.32"
+12"    1.34"   1.19"
+18"    1.20"   1.10"
+24"    1.09"   1.02"
+30"    0.95"   0.89"
+36"    0.81"   0.80"
+40"    0.71"   0.72"

Does that seem about right?

Now, a question before I proceed.  The stave is close to pipe-straight, but has developed a very slight twist since roughing it out about half a year ago, causing the tips to go out of alignment.  It also has some very slight humps and dips along it's length.  Considering this is an elm stave, I am assuming from reading some of Del's posts, among others, that the stave will certainly benefit from heat treating.  I am also assuming that now would be the best time to do this, and I could take out the humps and twist at the same time by clamping the back of the bow to the edge of a 2x4, one limb at a time, as I heat it. I could then take the bit of twist out with another heat session if necessary, and then give it a few days for the moisture content to stabilize again before proceeding with the tillering?  Is this a safe assumption? Any other opinions?

I'd take some pics but I don't think they would add anything to what I've described.

[WillS]

I don't know anything about elm or the best way to attack it regarding straightening, but I will say good luck, and I look forward to checking in on the thread to see how you go!

[adb]

Awesome Cam!! I can't wait to watch your progress. It'll be 2 firsts... first selfbow and first true warbow. Take her nice and slow. I'd actually be interested in seeing pics, to see how much it changed since you roughed it out in my shop. Those elm staves where pipe straight.

[Cameroo]

Well if you insist   As I mentioned, there are no serious issues, the only reason I even mentioned straightening is that if I am going to be heat treating anyway, I could kill two birds with one stone.

Side profile - nothing really to worry about.  Slight hump at dark knot on side of left limb, a bit of extra reflex in the right limb.


Small knot ran off the side of this limb, but will likely all be removed during tillering


The clamps on the limbs help show the slight twist.  Again, hardly worth mentioning, but you can see that the tips are no longer aligned through the center of the handle...


And also I had to show off this little jig I made for my heat gun.  It just screws onto the camera mount on my tripod.  Can be set to any height or angle   Can't wait for it's trial run

[toomanyknots]

Shoot, I'd say you got enough meat, given that the wood is dense, to make well over 110# @ 32. Although of course sometimes the wood is not so dense, so I would probably stick with those dimensions and watch the weight on the scale. When it is me and I have a slight twist like that, anymore I will just tiller the bow out to about a 4" brace, and correct the twist by removing belly wood on one side on the belly more than the other. I'll get it straightened out, and gradually work it in and bring it to a 6" brace. If it is seriously too twisted to brace, like dangerously twisted, I will try to correct the twist and then go to brace, see if it is twisting, unbrace, remove wood, repeat, etc. Very cool thanks for sharing.

[adb]

Too bad about the string alignment. In hind sight, I guess maybe we should have left a bit more meat on that stave so you could correct for drying warpage.

[toomanyknots]

Doesn't Dell the cat have a good steam bending set up for alignment problems like this? Or was that someone else? I got an osage stave I need to fix that has real bad alignment problems. I haven't roughed it out yet, but it is gonna need some tough lovin. Cool heat gun set up!

[Cameroo]

Ya, I had just assumed that with the moisture content being as low as it was when I roughed it out, that it wouldn't warp. Oh well, it's nothing serious.  I'll be putting some heat to it tonight, will update once done.  The plan is to heat treat both limbs, and then make alignment corrections after

[Del the cat]

Don't round the belly any more! (especially with Elm etc)
I pretty much leave 'em as rectangular cross section until I hit brace. Then I take the corners off a bit.
But with heavy weight bows I go for a flatter belly anyway*. A rounded belly may look pretty, but is (IMO) more of a Victorian thing.
Most of the Mary Rose bows are more circular or 'inflated square' in cross section, certainly not a high arched D.
I'd say it's a great time to heat treat, maybe even clamp it up with an inch block under the grip to add a hint off reflex, to allow for a little set as she progresses?
Del
* With My Elm warbow I had the back trapped a bit so the overall cross section was a trapezium with rounded corners. My only other Elm bow (D section) Chrysalled badly.

BTW, I called my 100# Elm Warbow "Dennis"
.
..
As in "Dennis Elmbow"  'Cos it agravates my Tennis Elbow

[Del the cat]

Too bad about the string alignment. In hind sight, I guess maybe we should have left a bit more meat on that stave so you could correct for drying warpage.

If you could bottle that hindsight and sell it, I'd take a couple 

I wouldn't worry about that tiny bit of twist, I'd just concentrate on the heat treatment and pulling the limbs tips into alignment.
Don't narrow the very tips until she's almost full draw and reay for the horn nocks.
Del
(BTW I'm just finishing a 84" ntn Yew 100# on my blog)

[Del the cat]

Ya, I had just assumed that with the moisture content being as low as it was when I roughed it out, that it wouldn't warp. Oh well, it's nothing serious.  I'll be putting some heat to it tonight, will update once done.  The plan is to heat treat both limbs, and then make alignment corrections after

Heat treating and correcting at the same time, saves time and dries out the wood less.
I try to spend more time jigging up the wood and less waving heatguns about (well it's held in a jig, but you know what I mean).
A couple of slats of offcut timber clamped to the sides of the stave will help keep the heat on the belly and also direct it along the stave, it gives a better heat spread and speeds it up a tad. Mind it's a pain trying to move hot thin slats along with the heat gun every four or five minutes
Del
PS. Sorry if I'm hogging the thread and telling you stuff you already know or didn't ask for....

[mikekeswick]

I'm making a 120# @ 30 elm longbow at the moment. I'm interested to see how your one comes out.

[toomanyknots]

As in "Dennis Elmbow"  'Cos it agravates my Tennis Elbow

  LOL   

[lostarrow]

 You're a riot, Dell! 

 Aren't you  on the coast, and  Adam in Sask.? Wood warps when it gains moisture as well.  I'm sure you already know this but just thought I'd throw it out for the benefit of all. I'll be following this one . Looking forward to the results, as well as all of the expert advise and knowledge !
    This site is a treasury of information!

[Cameroo]

Del, I was actually hoping you might hog this thread, so there's no need to apologize!

I will heed your advice for heat treating and try to bring the tips inline at the same time.  Luckily life got in the way, and I didn't get around to it last night (did I mention this could be a very slow moving build-along?  ).  And thanks for the heads-up on the flatter belly profile.  I wonder if maybe I should settle on a lower draw weight now that the corners are shaved off that much?  I'd rather have a functional bow when I'm done than achieve some arbitrary draw weight.  I guess I'll just keep a close eye out for set as I go, the wood will let me know what it is comfortable with.  I'll have to do some figuring to get an idea what the mass of this bow should ideally be as well.

Lostarrow - I'm fortunate to have Adam within 10 minutes of my home in Saskatoon, Sask.  He never hesitates to dish out advice or help a guy in need of wood

Mike, how long is your bow?  Feel free to post some pics and share info as you proceed