Want to try a boo, maple, sapele trilam.....any suggestions?

[Flntknp17]

All,

Have any of you ever used sapele as the belly wood on a trilam?  I have seen a couple bows that used it over on Facebook groups and they were really nice looking.  We are fortunate to have a super nice hardwood lumber store here that caters mostly to cabinet and furniture makers, but they have things like sapele in lumber sizes.....so I bought a straight grained 72x8x1 sapele board last week. 

I would like to start making some trilams.  I have made dozens of bamboo backed reflexed flatbows with various woods, but never ventured into trilams with a more ELB profile.  Definitely something I want to try.  I am planning to use a boo backing that is as thin as I can make it safely, then a 1/4" straight grained rock maple core, and then the sapele as a belly.  I have no clue how thick to make the salepe or how much to taper it before glue up.  I really like using some Perry reflex during glue up, but will probably only use an inch or so on a narrow bow like an ELB.....just enough so that I can hopefully end up at zero net set when its done. 

I am concerned about the sapele, it isn't quite as dense as I had imagined.  I plan on starting the bow at 70" long and my draw is 27".  Hoping for 45-50#.

Any thoughts at all are appreciated.

Matt

[Del the cat]

I think there is a lot of random hardwood about that is miss-named much of it may look pretty, but may be poor in compression. Personally I'd stick to recognised belly woods.
Nothing worse* than spending a lot of time making a fancy tri-lam only to have the belly chrysal. Save pretty wood for cores where there is less stress.
Del
* Well TBF there are plenty of worse things... but let's not dwell on the bad stuff. 

[bownarra]

Make some furniture with it Sapelle is a generic term here for anything pretending to be mahogany. Anyway all the stuff I've seen from my friend who is a cabinet maker is definitely not bow wood (I've seen a lot!). I wouldn't even use it as a core wood to be honest.
The maple will make a better belly but leave it flat. Boo is really too stiff for a maple belly though....
Your best bet if wanting to make tri-lam or more lam elb's is to get some quality ipe for the belly.
A boo backed ipe with maple core is a great combo.
Taper rate for an elb is around 0.009" per running inch. However you can't get them perfect off the form with grinding compound taper lams...
I would recommend a taper of 0.006" on the core if doing a tri-lam. Taper your boo so that it hand tillers to an elliptical tiller preglue-up. No need to go super thin with it.
If you used ipe for the belly then 1 inch wide over the center 12 inches, taper to 3/4" 8 from the tips then into 3/8th at the nocks. Thickness of 7/8ths at the handle. Somewhere just over 3/8ths at the tips. Straight line taper is ok for rough out.
Elliptical tiller. Make sure the handle only bends a fraction at full draw, you should hardly be able to feel it.

[Hamish]

Sapele is a lovely cabinet wood, but I definitely wouldn't use it for a belly wood. It should be fine as a contrasting core wood though.
If you can't get a proven belly wood, I would go for maple on the belly. Even then I would still go for a flatish wider design, than an elb.

[Flntknp17]

I’m beginning to wonder if the other folks I’ve talked to who successfully used sapele as a belly wood were misinformed and they actually had something else?  I guess I’ll just have to find out....nothing ventured, nothing gained.  I made a perfectly good bow of mahogany about 25 years ago so it appears to be possible. 

Matt

[Flntknp17]

I can see how my previous post could seem snarky or disagreeable if read with certain inflection......I didn't mean it that way at all.  I just meant that I have plenty of bamboo and 1/4 maple and sapele so I spent a couple hours tonight with the bandsaw and the sander and its all glued up now so we'll give it a shot and see what happens. 

Thanks!

Matt

[bownarra]

Just so you know I'm coming up on my 400'th elb, with many happy customers   I've tried just about every conceivable combo of woods in them. Sure experiment BUT a whole lot of woods will not work on an elb belly. It is a funny design made for yew. Yew has a strange set of properties that most woods can't come near to.

[Flntknp17]

Just so you know I'm coming up on my 400'th elb, with many happy customers   I've tried just about every conceivable combo of woods in them. Sure experiment BUT a whole lot of woods will not work on an elb belly. It is a funny design made for yew. Yew has a strange set of properties that most woods can't come near to.

I wasn't ever questioning your credentials in any way.  A lot of us have built a lot of bows, and experimenting is the most fun part.  I haven't ever sold one so I'm not a pro.  I plan to leave the belly flattened and not a full crown.  I do plan to cook my crow when I have to eat it and will report back.

Matt

[bownarra]

No worries I know you weren't Have fun and I hope it works out for you.