Boo backed built ?'s

[JSMOFFITT03]

Well I'm I'm putting the finishing touchs on my wall art glass bow( read the bubbles thread, I'm afraid to pull it back).  Next I'm planing on a boo backed hickory/Osage lam bow.  I'll be using the travaling caul pattern but have a few  questions.

1.  Glue-  I have some smooth on left over from my last bow.  I know urac is recommended for all wood lam bows but will the smooth on work as long  as I have good clean tight  glue joints.  I know that with boo you rake the  with a saw blade for glue prep.... Same procedure with smooth on?  

2.  Stack thickness-  I'm looking to achieve approx 55# @ 28" 62" ntn. With a glass lam it seems around.385"  total thickness is close. Atleast that's what my research tells me...
  Would that be the same for boo?  

Any recomendations?

Thanks

[rbbhunt]

Go ahead and use the smooth on.  I quit using urac for all wood bows as I have the smooth on and I feel it has a longer pot life than urac.  Gives me more time to get things lined up and clamped down.  I just sand the back of the bamboo with a 36 grit belt on a belt sander.

  As you are making an all wood bow, I would start a little thicker with the hickory/osage stack-up.  It depends on your limb design.  You can always sand some wood off to bring the weight down.  It's harder to add wood!!!?!?!?

[Bowjunkie]

Smooth On will work fine. Make your gluing surfaces flat, but not smooth. Too smooth and the joint is starved of glue when pressed together. Think about the surface of a ground lam that you would buy for a glass bow. Make it similar with a toothing plane blade, bandsaw blade, corner edge of a file, coarse sandpaper, or whatever.

.385 would get you close, not counting the bamboo. It would depend of course on your profiles, widths, etc. The last tri-lam I made was boo/osage/osage.

The boo was made as thin as I could make it... approximately 1/8" at the center and 1/16" at the tips.

The center lam of osage was 3/16 parallel from dip to dip, then tapered from each of them to the tips.

The belly lam of osage was 1/4 parallel.... leaving wood for removal during tillering if necessary.

The bow is r/d in design, 58" ntn, 1 1/8" wide and ended up being 57# @ 28".

I could go out and measure the exact finished dimensions on this bow if it would help, but basically you just want to set it up so that you're not scraping/sanding into the first glue joint during tillering.

[JSMOFFITT03]

thanks guys....  exactly the kind of info i was after....

ill keep you posted..