Using Ipe....The Good, The Bad, and The Ugly!

[canopyboy]

I did work the mid limbs a bit more.  Put it on the short string and bam! Already slightly under.  Well, the form/caul was really too long for the draw length I was aiming for, so I shortened it up.  Bow seems better now, although we're getting to where there is more deflex than reflex.  Lower limb still too stiff, but has what I think is a perfect tiller.  Upper limb looks ugly, but is already too weak.  Well, not that bad I guess.  I'll play with it a bit more.  I only have about an inch or so of draw length left to play with.  It might be a little under weight.  I think I want to do a straight glueup next time!

[SEMO_HUNTER]

That's exactly what can happen with this design, the mid limb won't bend and won't bend, then just goes all at once. It's very touchy about that.
If your bottom limb is the stiff one you can pike it a bit by nipping an inch off the top, if you have that much to play with?

You will lose about half of the reflex when it's tillered. The trick that I've found to combat this (in my limited experience) is to leave the tips a bit stiff.

[StoneAK]

On the caul design I usually leave the tips a little stiff for that same reason Semo.

[canopyboy]

Yep, caul design had stiff tips, but when I screwed this one up, I had to shorten her up to the point where I lost most of that benefit.  Oh well, she shoots fast.  And smooth too.  Time to get some finish on and move to the next bow.

[SEMO_HUNTER]

Until I can get some more experience tillering the R/D design that the caul puts into the bow, I'm doing my next glue up exactly like I did my trade bow. Straight profile with the tips raised 3 1/2" with blocks under the tips. It tillered just like a regular longbow and I used the gizmo the whole way.
The BBO I just made is a screamer and accurate too, so I can only imagine what it would be like with Ipe on the belly. That's gonna be my next project along with practicing on some Hackberry out of my caul.

I got 1 last piece of boo left and I'm not taking any chances with it cause I need a back up bow for fall and if it turns out the way I hope it will then it may be my first choice?

[StoneAK]

Chris,
     I use a planer and cut down the ipe a little then it bends nicely on the caul. It is a very fast bow off of that design.

[canopyboy]

Thought I was a couple more coats away from being ready to ship:

   
   

*^$%!&^     :mad:    :mad:    :mad:   &^%@$%#IPE!!!!  

   

I put it up to check weight one more time before inscribing.  And there it was.  The bow had more than 50 arrows through it already, but seemed destined to fail before long.

   

       

Today I'm going to salvage the bamboo off the first one since it was too thick anyhow.  I'll grind this one down a bit and put a boo belly on it too -- I don't trust that plug all by itself.  Besides, the bow was a couple pounds light and I keep thinking a boo-ipe-boo was going to be my next bow anyhow.

I'm a little nervous, as I think I need to have the tiller pretty close before the lamination.  I don't know that I want to scrape the boo belly too much to get it right.  Might be caliper time.  Not to mention the deadline is breathing down my neck now.

I'm also going to check the ipe board I have.  This chrysal was pretty much exactly where the other one was.  Could be I'm screwing up the same way, but it also looks like there is something funny with the grain there.  I want to see if I can find it in the board.

[StoneAK]

How wide is your limb? and how thick was the Ipe?

[canopyboy]

I will be measuring, and can post the dimensions at the location of failure.   But this bow was about 1-1/8 at the fades, 7/16 at the tips, and the ipe was about 3/8 at the chrysal although it tapered pretty evenly.  The first bow had the same problem, same place, but was 1-3/8 and the ipe was a lot thinner (and boo thicker).

Oh well....

[canopyboy]

VINDICATION!!!          

This is the off the same board.  I didn't see it at first, but I laid the ipe blank up next to the bow and .... nothing.  Swapped it end for end, and BOOM -- there it was.  Lined right up.  Filed and scraped it a bit to make sure it was really there.

   

So the whole board has it, all the way through the thickness.  It's not a knot of any kind.  It's almost like it had a fret from when the tree was felled, or at least before it was milled (why else would it go all the way through the thickness?)

I can't believe it.  Just my luck.  I was so careful the second time too.  Oh well, I think my boo belly idea will still work nicely.

[fujimo]

man i am so sorry for you chap!!
but nice neat save- and should work out just pretty.
when you are dealing with this many crazy problems- people will sure be understanding- dont give up!!
well done

[SEMO_HUNTER]

As I was reading down through the posts before I saw the pic of your board I was going to suggest that maybe you got a bad batch of Ipe, but you already figured that one out on your own.

Man, that's pretty crappy and I hate it for ya. You work your tail off to do everything right and the fault is all on the wood and not the bowyer........that really sucks!

I hope you can save it.

[4est trekker]

Canopy: you don't want to sand the boo to drop the weight or adjust the tiller. On boo bellied bows, you use a combination of removing side material, trapping, and knee tillering (which is a scary technique of gently, but purposely inducing set in localized areas of the limb in order to achieve even tiller).  I came across this technique while doing some work for James Parker of Huntworthy Productions.  James makes some of the best boo and composite bows I've ever seen.

And yes, you certainly want to pretiller all lams, particularly the boo, in order to get in the ballpark right off the bat.  Hope this helps.

[vanillabear?]

[canopyboy]

4est-
Did my best to pretiller.  We'll see how it works (everything is another experiment with me) in a couple more hours when she comes out of the oven and cools off.

vanilla-
The reason I noticed was that after flexing the bow with the first few coats of finish on, you could see the cracked finish.  Flex it a little more and you could watch the movement at the crack.  In hindsight, since I was going to grind it down and add a belly lam anyway I probably would have been fine to leave it.

[KellyG]

well now what to do with that board. And I am just brain storming on this. If it is not long enough to just cut that end off; you could make billets, or heck even cut it down and use it like horn. Say make you a hackberry, hickory or other bow and put the Ipe on the belly. I have a hickory I am going to try that with Osage on back and belly. It was my first try at a bow and did not end well. But the back split off so I think Osage belly and back might save that one. Who knows just brainstorming.

[canopyboy]

I figured it would get used billet style.  Actually, the board is long enough that I could get the defect under the handle and it would be fine.  I'll figure it out when my wife lets me start another bow...          

Well, the bow is cured, cooled, and I took it off the form just now and cleaned it up a little.  The boo-ipe-boo looks good, although the glue lines as I tried to get it to bend up the fades were less than great.  But I think is good enough for far enough to get the job done, and the rest can be rasped off.  I tried pre-bending the boo with dry heat which seemed to work.  But I guess my clamps in that area just weren't good enough.  I guess that's why the glass guys like air hoses.

I couldn't resist putting it up on the board and pulling on it at least a little.  Braced tiller looks good, I pulled it to twenty inches and 47#.  Lower limb needs bend a little more mid limb, but not too much.  And I'll need to drop some weight.  Although not too much really, actually it might be only a about 5-8lbs over at final draw and weight as it currently sits.  Just enough to do what I need to do and get it sanded smooth.  

I don't know how much time I'll have tomorrow on it, but I have all day Friday and Monday.

[StoneAK]

Sounds like you got a good fix going on there can't wait to see it

[fujimo]

awesome save!!!

[canopyboy]

Thanks, I'll consider it saved when it's all finished and in a shipping tube.

I'll try and post some pictures tomorrow.

-Dave