Elm Stave Bow

[PlanB]

I think I'll follow that DC! For both. 

[PlanB]

Any suggestions for how much reflex I should have left after heat treating?

I'm trying to figure what shape the caul should have for this one. Probably you'll need the specs to suggest it......

The specs so far:

Elm, 66" tt,
stiff handle
limbs unequal length (32" and 34")
fades 2" wide, and limbs untapered to 14" from tips, then tapered to 1/2" presently
Reflex of stave was 6-1/2" to start
Reflex now is 4-1/2" total.

Presently the limbs taper in thickness from 7/8" at fades to 3/8" at tips approx. That's measured at the side, with crown at center,  the limbs are actually thicker.

I've been tapering  to reduce evenly and gradually, consistent thickness  side to side, taking into account the irregularities of crown, knots etc. I've left tips thick for now.

Floor tiller presently gets both tips bending to in-line with handle before stack feel says "no more" to me. I see what looks like even bend along the length of both limbs. Longer higher reflex (upper) limb is noticeably stiffer than the lower..

[willie]

I hope that Plan B doesn't mind a bit of a sidetrack. I have read the " train the limb from green", and the "adjust it when dry" approaches and I realize that the best idea might be to restrain it while green, and make less of an adjustment when dry.

Corrections to the limb are sometimes reported to "pull out" or the bend "reverts" some, and needs to be readjusted.

Do "dried from green corrections" have better longevity that those applied after the wood is dry?

[bowandarrow473]

I do a lot of corrections while the wood is green with clamps and a board or other straight object, never had any problem with them pulling out, but you do get less correction when you dry it from green, as the wood will spring back some. Then again, I mostly am adjusting side to side bends, not deflex or reflex as I don't cut wonky staves unless they have a nice reflex or a nice reflex deflex design to them. I'm also not into "character" bows with a lot of reflex and deflex kinks but I like the look of them, I do, however build bows with snake and knots and like doing so.

[bushboy]

I like to reduce the outer limbs closer to final dimensions early on to order to get a better look at the floor tiller.with that much reflex coming out of the handle makes it tricky to tiller and brace.i like a little coming out of the handle and progressively more towards the outer limbs

[Josh B]

I prefer the basic reflex shape that bushboy is describing.  If your a boat builder then you know how to use a batten strip to draw smooth curvature.  Making a call is pretty simple.  First get you a 2x? , find your center point equidistant from each end.  On the flat side of the board make a mark about 3/4" down from the edge.  Next move out from the centerline 16 1/2" (basically midlimb) make a mark 1 1/4" down from the same edge as you made the first mark.  So now you have 3 marks. One in the center that is 3/4" down from one side, and 2 marks at approximately midlimb 1/2" lower from the same side than the center mark.  Still with me?  Good. The next marks are 8 1/4" away from the last two marks and 2" down from the same side. Make your marks.  The last two marks are 8 1/4" further out yet  and 2 3/4" down from the side.  If I didn't confuse you, you should have 5 marks, spanning  66" with an elliptical curve that should yield about 2" of reflex.  Now start a small nail into each mark.  Not all the way flush just deep enough that the don't wiggle.  Now lay your batten strip along those nails and secure with a couple more nails.  Make sure your batten strip is touching all the nails and is bending smoothly and then trace along the edge of the batten strip on to the 2x?.  Remove the nails and batten strip and cut out your elliptical arch. Smooth up any humps you left from sawing it out and you have a caul.  Josh

[PlanB]

Thank you Bushboy, Gundoc, DC, Bowandarrow, Willie!

More gooder?

[Josh B]

Much gooder!   . Josh

[DC]

When I was making my caul, I layed out one side and cut it off as accurately as I could. Then I used the offcut to mark the other side. I trusted that more than my measuring.

[PlanB]

I left the tips un-heated in case I decided to give them a little more reflex.

But I've been thinking that as a newcomer, I probably shouldn't, because the tiller will be easier to judge if everything is fairly straight, and that was the whole idea just now in evening them up.

Where I am:

Reflex overall is now just under 2".

That's down from 6-1/2" in the original stave, and 4-1/2" where I was after roughing out and floor tillering.

I'm guessing some of that 2" will disappear after tillering.

Probably I shouldn't try to get fancy at this point. I do have 3 more elm staves from the same tree and section, and they are better than this one, so I could try something more interesting after this one -- if it works out.

[PlanB]

Put in a half hour of floor tillering and I think it's ready to brace. I'm going to make a string for it tonight. The reflex is now 1-1/2"

[bushboy]

If you lost 5" before brace makes me think the wood is not quite cured?

[PlanB]

Bushboy I just checked and the meter says 9% tops in places checked. Most of the reflex came out from clamping the bow to a form and heat treating. The belly is even drier, not even registering, but I imagine that's from recent toasting. Checked the meter calibration and it was good. I dunno.....

[bushboy]

Didn't catch that you heated out the reflex,sorry bout that.should be good to go,although I believe it takes more time for the wood to fully cure than being dry.looks like a nice stave for sure,good luck man!

[PlanB]

Thank you!