Which core wood for bamboo-???-ipe trilams?

[AndiE]

Hi

I got cheap bamboo backings and free ipe for the belly (10 pieces each and 88,5" long at the moment!)
Now I don`t know which core woods I should take!?
What are your favourite core woods? What would you guys take?

One will be a bilam bamboo-ipe and one will be a trilam bamboo-purpleheart-ipe.

Kind regards
Andi

[toomanyknots]

Score,  . I've seen people giving away raw fresh bamboo on craigslist before that they grow, real big stuff too, I've wanted to cash in on such deals but the wife is never too keen on me driving so far, gas money, our van sucks, etc. (speaking of that, anybody grow their own bamboo? Now there is a good idea!). Anyway, I like maple for cores, you can find it everywhere, for cheap too. Hard maple is probably my favorite core wood. I don't like using heavy "belly" woods for cores that much, you can get better cast with woods like maple. Yellow hearts good too. That's just my opinion though, definitely not set in stone or anything.

[AndiE]

Hi

Ok, you prefer the lighter woods.
I set those on my buying list.

Kind regards
      Andi

[Bearded bowyer]

Hi
I've used Beech, Cherry, Ash, Hickory, Black walnut, and Oak as middle lams.
I love Oak, but that may just be a British thing 
Oh and Ive use Bamboo and yew. Both very light. Makes the bow much lighter with less limb mass.
As far as I'm aware there aren't any 'rules' as to core laminations. I get all sorts of requests, mostly based on what people think looks pretty..........
Matt

[AndiE]

Hi

Beech and oak? Don`t they crack?
Which woods are absurd as core? Rattan, pine, spruce, willow...?

Kind regards
Andi

[Bearded bowyer]

Hi
Ive used Beech several times as a core lam with ash back and ash belly, never had it crack.
The oak cores Ive used have been quite thin, but really seem to make the bow straighten asap. They have been very fast shooters.
Haven't had a problem with either woods cracking........yet
Isn't rattan a type of bamboo?

[toomanyknots]

Although, I think if you use a softer wood, make sure to taper the ends. If it is not good in compression, and there is a spot that there is equal core to belly, it may take more set than usual. So I taper my cores to where there is always a majority of belly wood for the most part, at least when using a core such as hard maple, or any maple, or yellow heart, etc. I know most people believe that if it works as a belly wood, than it will work as a core, which is a rule you can go by if you want.

[AndiE]

Hi

Do you taper the backings too?
And with hardwood like laburnum or purpleheart as core there is no need for tapering?

Greets
             Andi

[toomanyknots]

Hi

Do you taper the backings too?
And with hardwood like laburnum or purpleheart as core there is no need for tapering?

Greets
             Andi

I think tapering is still a good idea, I don't know how those two woods do in compression. Hard dense woods can still be weak in compression. If you do a thinner core though you can get away without tapering if you want, a lot of times I will do that. Sometimes I taper backings just because that is what the belt sander wants to do, especially when reducing the thickness of a bamboo backing. I don't think it really matter either way though.