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Originally Posted by Waxing_Gibbous
. Also I just can't shake the feeling that wood might de-laminate or get eaten by termites, but clearly other people have no such issues.
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I have never ever heard of termites eating a telescope - you should be using and shifting it about too much for them to find it, anyway! And the glue in the laminates would put them off, I would think. I know someone who wasn't serious about their astronomy left a basic 6" dob on the veranda and bees set up a hive in it, but that's probably the worst, and only happened because he had basically abandoned it. Also the bigger scopes tend to get made with marine ply, which is better quality than the thinner cheaper ply at the local hardware (as you probably know, having a marine background). Good scope maintenance means drying the dew off after an observing session so there is no reason why moisture intrusion leading to delamination should be a problem. The biggest problem I see is just nicks and dents in the finish, cosmetic problems, not structural.
You tend to see so much wood used in big scopes as the north Americans have a love affair with and disdain metal in telescope contruction, and they are the most active telescope makers in the english-speaking world (Europe does have some active atm-ers and big dob beauties, but the language barrier means they don't often come to our english-speaking attention). There is a couple of reasons for this. One is they are lucky enough to have a large range of different woods on hand at cheap prices. Another is they do it just because they can. But more importantly there are some that believe the expansion/contraction properties (I've forgotten the correct term, forgive me) of metal are too large to make a useful scope. And when you have a huge diurnal temperature range, like up in Canada, they might have a point. Here in Australia the diurnal ranges aren't so large, so using metal isn't such a problem.
If you want to make an all metal telescope, go for it. Plenty of people here in Australia have and the scopes work just fine. There is no reason why you have to copy-cat anyone, anyway. If you know the principles of a telescope build there are many ways to solve the problems - or as the common saying goes, "There is more than one way to skin a cat."