How about making the internal braces with the curved sides. Then take 3mm mdf cut to size and wrap around the curved side of the braces, glue and screw down. let it dry and then add another 3mm MDF layer, screw & glue down.
laminate to appropriate thickness. would that work?
I tried this once. The problem you face is that you will run out of places to put the screws after the 2nd or 3rd layer. The other issue is that the screws apply pressure to only a small area of the work, thus your surface will not come out as smoothly curved as you want it to be.
way I'm gonna do it (if I don't go the carbon fibre route) is to use 16mm MDF and have it kerfed and then to use 3mm veneered ply and stick it over the kerfed mdf
When you bend the plywood, it cannot contract on the inside of the arc, so the only other way for it to bend is to stretch the outer layer. With your average veneer being about the thickness of 160gsm paper, this will most probably cause small splits and cracks in the veneer.
There's also a product from a company in KZN - bendable-plywood-veneer-type sheets-stuff-3mm-thick that looks very promising, but I can't find any in CT area. Dunno if it's exactly the same as normal 3-ply??? Grrrrrrr!!!
I have some of this bending ply at home. It is not very strong at all - I can tear a 5mm thick piece with my hands. Unfortunately I am not convinced this has an application in speaker building other than to make a mold from.
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Carbon fibre can work, and is not too difficult to lay up, but the problem (as has been rightfully said before) is the cost. You will need many, many, many layers before you even reach a thickness of 3mm. What many people do is to make their part out of standard fibreglass, then add a single layer of carbon fibre to the outside. This helps with the cost issue seeing as fibreglass is substantially cheaper than carbon fibre.
That being said, even if you used only fibreglass to make your enclosure, the cost will be prohibitive because of the thickness you require the sidewalls to be.
Honeycomb and the like is an option that will give you the thickness and strength you need, but that will cause the cabinet to ring like a bell because the sidewalls will simply not have enough mass to damp the vibrations. Yes, it could be filled with sand before the outer layer of composite is added on, but of course you are now playing with some very tricky, messy, and potentially unsuccessful ideas.
Stick to wood - it is the easiest , cheapest, and the fastest material you could use to make a cabinet out of.
Regards,
Ian.
