Birch and Ash board bow projects

[PlanB]

I was thinking that, wizardgoat. Taking a careful look at the fresh cut edges of the bow blank I found two places where the grain hooked, and I've finally decided this piece is a no-go for me. Bowandarrow473 I think you were right to question me on this one -- thanks, one more lesson learned here.

Bubby, I believe what you said about all being possible. But of course, the rub is, is the board good enough to pull it off -- especially without backing.

I think a board has to be absolutely perfect for an unbacked flat sawn bow in ash.  I think now that good vertical grain (quarter sawn) blank would be easier to find, and the ring runout wouldn't have been a problem unless much more severe.

When you think about it, a bow with vertical ring orientation always creates runout at the edges of the bow, since the bow limbs taper. But as long as the grain is reasonably straight and parellel to the bow, bending is always going to be perpendicular to the rings, so they aren't subjected to shear the way they would have been if flat to the back.

Diagonal ring orientation is going to be a somewhere in between.

I looked for a quarter sawn board in my stack, found a couple, but those both were spoiled by one or two worm holes. So I'm going to give up on ash from this particular tree, for now. I'll wait until I cut a better one, and I'll keep in mind the need for quarter sawing, next time when cutting it up.

The birch looks good so far, and I still have a nice birch stave with the back on, so I'll keep on with that.

[PlanB]

I've let the birch blank dry some indoors, and it's now time to add the handle riser and rough it out for a bow. Looks like I'm probably going to be able to keep it the full length of the blank, 68" since there are no checks in the ends. I'm leaving it to dry further at this point.

[George Tsoukalas]

Be careful. I thought I saw some almost circular ring lines in a picture in the foreground. That indicates a knot which is nearly always fatal. Jawge

[PlanB]

Thanks George. I think what you're seeing is the shadow of the bevel on the belly. (If you're talking about the birch photos directly above, and not the ash pictures earlier in this thread.) Because the bow blank is lit from the side, the bevel is casting a shadow, which makes one side look darker in color.

I band sawed the birch blank above, and I cut it from marks on both sides, canting the blank slightly while sawing. That leaves a bevel in the middle of the belly, more or less -- kind of like when you take wood off the belly, by first beveling, then flattening. There aren't any knots in this blank. I haven't flattened the bevel yet -- I'm letting it dry more before working on it.

If you are talking about the ash board earlier in the thread -- I've shelved that one because of grain runout that I found once I cut it down.

[PlanB]

Just an update, I thought it would be interesting to just add  the drying progress here. I've checked the weight of the roughed out blank every day and marked it, with the date, in pencil. The bow is in a room with occasional wood heat, though not placed near the stove. the humidity in the room is averaging about 50% Here's the weights in grams and dates so far:

11/5    1045
11/6    1031
11/7    1025
11/8    1014
11/9    1004
11/10  994

That's about 10 grams or 1% per day. Which seems fast to me. I'm surprised at how steady that is, too. I'm going to be interested to see when, and how fast, it levels off. There are no checks, no warping or any change in the 1-1/2" total reflex so far.

Edit: continuing

11/11 986
11/12 984

[willie]

Planb

howdo you monitor the humidity in the room.  50% is good for keeping the board at equlibrium, but may be a bit high for getting it down to equlibrium ,unless the wood was fairly damp when you started

[PlanB]

Willie, I have a small inside/outside temp and humidity meter in the room.

I think 50% RH indoors is optimal for health and what we strive for. It will drop, unfortunately as winter gets here.

50% correlates to 9.5% wood MC. In summer both indoors and outdoors are higher and where a bow will be stored and used respectively. The exact numbers aren't important, the intended useful environment is.

[fiddler49]

The ash board could be used if you use just one side or the other where you see the end grain is in this orientation///////  about 30 to 45 degrees. This is usually called riff cut. The middle of the board is flat sawn and would need a backing or chase a ring. I've made lots of good bows from riff cut boards.

[riverrat]

use the middle {chase a ring} and use the right side {riff} there ya go 2 bows. Tony

[PlanB]

Thanks Fiddler, Tony.  This is what I saw on the edge of the ash board once I had cut the plank down more.  It's about mid limb. I should have looked at the face ring pattern to realize this kind of hoogie lies under a ring island -- you can see that "island" pattern on the face. I think that's what George was taking about above.

[PlanB]

Just an update. I've been working with the black birch board bow, and gradually getting it shaped with heat, tillering and shooting in. I'm not done yet but I think it's it's getting close. I've left the finish off for now.

I have about 300 arrows through it now, and I think it's going to be a good one, for me. This black birch (Betula lenta) really has a noticeable ringing tone to it when you rap it with a knuckle unstrung. Noticed that even when it was a board. More than my elm stave bow when you rap that. It feels zippy to shoot, too, by comparison. It's holding its shape very well after shooting. I had to deal with a little propeller twist at one tip -- I almost have it all out. I don't know the final draw weight yet, but I think it's going to be close to my target of 45 lbs @ 27"

Here's what it looks like right now, unfinished:

[bubby]

Looking good

[bushboy]

Looks good!you put the set in the right spot!

[willie]

Zippy bows are always a good feeling.

Looks like you put a little heat bend in the tips. Did you do that dry? Did you do the whole limb also?

One place I read recommends steaming for birch, and another place I read that heat treating doesn't work too well with birch. Don't know what to think sometimes......

[riverrat]

lookin good! Tony