osage board bows: 2 at once

[radius]

ok, i took the time to tiller some wood off the bow with the trouble spot... here are some images...notice that when I freehanded on the table saw (cutting outside the line) I cut nearer on one limb than on the other...most of the work of tillering has been off this thicker limb.


These pictures are all taken at about 13 inches of draw....

[radius]

the bow is still very heavy, just like i intended it to be...and I can feel it tensing in the handle as I draw....

anybody know what I can do about the wane on the edge of this sucker?  Do you think steaming bamboo will cause it to conform to the shape of what's there, and still be strong enough later to be durable and "stand the test of time"?

[Gordon]

There's no way you can safely back with bamboo with that missing wedge of wood - the back has to be flat. And even if you could back it, that wedge is creating a weak spot that will likely cause the bow to fail.

[adb]

I agree with Gordon... that piece of wood needs to be backed, and you have to make it flat first. Do you have a belt sander?

[Ryano]

You could cut out the void area and patch it with another piece of osage, just cut it out from the edge with a bandsaw and glue in a new piece and work it down. Then glue your bamboo over top of the patched area.

[El Destructo]

You could also go Modern World...and get e Router...and cut out just the divot area....as deep as necessary to flatten it out....cut a replacement piece and glue it up....then Back it.....or just toss the dang thing and start over....the easiest choice......

[radius]

hey, thanks for the advice guys!

toss it?  uh, no!  My very best bow to date has a similar thing to that, but it's not just wane, it's actually grain run off where the board had been damaged...but it's hickory, which use could launch a space shuttle from and not see any damage...

I hadn't even thought of belt sanding the back off until it was flat...that's not a bad idea...that would almost complete the work of tillering, too...i think i may go for that, and then back it with the bamboo i've prepped in a reflex to gain some oomph.

[radius]

Come to think of it...my router is missing me a little...and I have some extra osage tapered pieces from where I table-sawed the extra wood off the belly...that's the way to go, I think...

[radius]

OK...

Since this is a 2 at once, compare and contrast buildalong, i left the waney one leaning in the corner today, and after work I rasped and scraped the pondsawn one for awhile.  The thinner limb has a minor hinge in it, so i can't draw it very far.  I want to even up the limbs (minus the hinge!) and then, when the stiffer limb is bending with the thinner one, clear up the hinge and chase my draw weight down to full draw.

Contrast scraped and rasped wood.



Same spot, from other side.



Here it is at about 13 inches draw...just before the hinge starts to show....



I'd like to work on it some more today, but I've got to meet the boys for a few...next time..

[radius]

ok...finally got one on the short string...

tillering with a scraper and rasp were taking too long and eating up too much energy...so I switched to rasp and orbital sander...awesome combo...fast wood removal where needed, plus smoothing in very little time....

You see I have a clamp on my tiller stick...I originally had it at about 13", and drew heavy on the long string to get the string into the groove.  That was a couple sessions ago.  Yesterday I had the long string at about 16" pulling the same effort.  Then I tillered some more, getting the hinge out and evening up the bend, to find that with the long string and the clamp at 16", very little real effort was required to hitch the string on the groove.

Here is a picture of that....



So I made a string about 2" shorter than the bow, and put the clamp back at 10" or so.  This forced me to exert more energy to get it set up on the tillering stick.    Here is where it sits now...



So, now that I've got it to this point:  where it is evenly bending at the high weight I want out of this bow...is now the time to put the bamboo backing on?  I mean, it feels to me like I could get this bow to full draw and full weight without any backing at all, despite grain runoffs...but common advice goes against this, right?  If I tiller it to full draw and then back it, i'll raise the weight 5 or 10 pounds, I guess, and have to touch up the tiller...

What do you say, guys, now or later?

[Ryano]

Now!!!!!!! Dont bend that thing any farther or you'll be sorry. If you glue your boo on in reflex your goin g to gain a whole lot more than 5 or ten pounds. You'll need to start the tillering process all over again. Dont rush it faster isnt better when it comes to tillering bows, just go slow and take a break and do something else for a while if you tired or sick of scraping it. Come back later with a fresh mind.

[radius]

OK!

It's cold out this morning, but I trimmed the bamboo to shape (slightly over) and sanded it down futher....here's what it looks like now...





But...because it's cold out, I didn't want to work with the epoxy...so I brought the bow to the table.  The first picture is the bow with nock to nock string, a bit loose, at 12" draw.



Now I tightened the string up a little.  It's not braced, but it is tight against the handle.  The clamp is still at 12" draw.



Keep in mind that every time I set it on the stick, i check the bend with a block, and mark the flat spots for work.  This next photo is at about 14" of draw, string tight against the handle.   It took a lot of effort to pull the string into the groove, and yet the bow shows no set at all.  The curve is symmetrical and even.  Lifting the string into place takes so much energy that the table comes up:  I have to hold it down with my feet!!!  After taking it down, I wondered how heavy this bow really was.  After all, I have no scale.  So I came inside and strung my 65# hickory bow.  After working with the osage bow, the 65 is easy to draw: no problem!  And so far I have heard nary a crack or a creak....

Here it is at 14" draw.



Next step:  low brace:  say, 3 or 4 inches or so...

Hope it doesn't break!

[Gordon]

Why are you going to brace the bow before gluing on the backing?

[radius]

sounds like you think that's a mistake!

I don't know...because I am an experimental bowyer...I'm like Tim Baker that way...no hard and fast rules other than have fun, keep trying, keep it interesting...

Everyone says it's gonna break without backing...and I like to take the advice of more experienced guys, no matter what i'm doing...but this one feels pretty strong to me, gives no sign of breaking (no eerie sounds, and no hinging).  I think that people are afraid it's going to break, but I tend to doubt what "everyone" says.  And I look at this buildalongs...don't people often make the bow and then throw a backing onto it?

If I make the bow, then add the backing without reflex...what effect will that have? 

Do you make osage board bows without backing?  Or with backing added at the end?

Maybe I'm just a dolt!

[stiknstring]

I do not think you are a dolt...heck i don't think ANY of us think that.  He was just curious about your procedure.  Typically the procedure goes something like rough out the bow...floor tiller then back before tillering the beast.  It is especially true when adding a hard backing such as bamboo or hickory. 

What I really think it boils down to with Gordon's question is asking about your thought processes so we can understand what you are doing and why....then will come suggestions......does that make sense???