Bamboo Baffles

[jadybug]

I found some bamboo stair risers at Rona Home and Garden. They are 7 1/2" x 42" x about 5/8" thick They look like the picture at the bottom of this page
Bamboo, Cork Flooring, Strand Woven - Ontario, Canada
I have never worked with this type of wood and am wondering if regular carbide router bits with work? Most of these risers were bowed in the middle and I had to through a few to get flat ones.
Thought I'd ask before I destroyed one.
It would not be used as a stand alone baffle but would be attached to 1/2" birch ply. Any idea of bamboo's strength as a stand alone baffle in a small speaker?
Thanks

[planet10]

You will be fine, you just have to be careful with warpage.

dave

[Poindexter]

My only advice would be to try and design your box to require the least amount of milling of the material possible. That stuff is a bugger to cut and work.

Aloha,

Poinz

[jadybug]

What kind of problems have you encountered? All I can foresee is splintering against the grain making the driver cutouts?
Jadybug

[Pano]

Bamboo ply is a great material for speaker baffles and boxes. Very dense, stiff and pretty.

But as my old buddy Poinz points out, not easy to work. It can be very tough on blades and bits. But if you are doing just 2 baffles, shouldn't be too bad. Poinz probably had to do whole houses with it! =)

I've seen the bamboo done in a simple oil finish (by me) and also in super high gloss (Ascend speakers). Both are nice.

[planet10]

I don't think Chris complained about its machineability, but the bamboo ply we used does require more thot, care (and $$$) to work with.



dave

[chrisb]

Originally Posted by Poindexter

My only advice would be to try and design your box to require the least amount of milling of the material possible. That stuff is a bugger to cut and work.

Aloha,

Poinz

yup - use only sharpest tooling (freshly sharpened or new 60+ tooth carbide ATB saw blades and NEW carbide router bits)

Originally Posted by jadybug

What kind of problems have you encountered? All I can foresee is splintering against the grain making the driver cutouts?
Jadybug

There are quite a few variations on construction of laminated bamboo panels, all of which offer their own challenges in attempting perfect cutting - but as noted above, I found new sharp tooling and slow, uniform feed rates most helpful. In the case of 3/4" 3-ply used in the boxes in Dave's photos, the outer plys were approx 1/8" - by cutting the mitered edges up, I was able to avoid chipping on the cross grain.

The pictured pair originally had a different driver ( CSS FR125), which were rebated for flush mounting. Those cut-outs, the walnut insignia inlays and the walnut suprabaffles for FE127E were routed on a CNC with carbide tooling at high rotational speed and slow feed rate - they all came out fairly clean - nothing that a little Famowood natural wood filler couldn't remedy.

Originally Posted by panomaniac

Bamboo ply is a great material for speaker baffles and boxes. Very dense, stiff and pretty.

But as my old buddy Poinz points out, not easy to work. It can be very tough on blades and bits. But if you are doing just 2 baffles, shouldn't be too bad. Poinz probably had to do whole houses with it! =)

I've seen the bamboo done in a simple oil finish (by me) and also in super high gloss (Ascend speakers). Both are nice.

The boxes below were "natural" ( meaning probably bleached somewhat) finished with several coats of post catalyzed nitrocellulose lacquer. The "inlay" effect on the perimeter is simply a matter of utilizing the exposed end grain of core cross bands on rebated front baffle.

Originally Posted by planet10

I don't think Chris complained about its machineability, but the bamboo ply we used does require more thot, care (and $$$) to work with.



dave

well, there were a few curses that Dave conveniently forgets - this stuff can definitely be a challenge, not so much for it's machineability, as for other factors:

- even though bamboo is the fastest growing harvested plant, it is a very time consuming and expensive process to fabricate the laminated plywood panels, so at approx $300 a sheet at the time these were made, you want to plan your cuts carefully, particularly if grain pattern wrapping is intended

- once opened from the hermetically sealed wrapper in which they are shipped, if humidity/temperature conditions are off they can easily warp, particularly when cut and internal tensions are disturbed. ( we also find this happens a lot with "imported" plywoods of more conventional materials - a large volume commodity we use in the commercial trade is generically referred to as "meranti", but a wide range of species and glue formulations are used - some of this stuff will bow or twist over an inch in a 8ft rip once the panel is cut)

- bamboo is just hard enough that if you have adequate tooling to produce clean bevels (such as the miters on the Pawos in photo), it can hold an edge sharp enough to cause serious damage to your flesh

All things considered, the bamboo plywood is not that much more difficult to work with on "conventional" boxes or Open Baffles, but more complex designs can be incrementally challenging:



chris

[jadybug]

Thank you Chris for your detailed reply. I see the wood as being very hard as a homogeneous unit as produced and cut edges can weaken the unit. Any cut edges would need some sort of clear sealer/adhesive to maintain integral strength! Just a feeling!! I think I will go out and buy some bamboo cutting boards at Winner's and test the tools out on them first.
Jadybug

[Pano]

Originally Posted by chrisb

The "inlay" effect on the perimeter is simply a matter of utilizing the exposed end grain of core cross bands on rebated front baffle.

Yes, it's a very cool effect built right into the plywood! Pretty....