Yep, due to my cunning design, there will be no aluminium parts that can be got around. I'm going to lap-join aluminium flat bars to make a rectangular base and butt-join (with mitres) to make a top of the same dimensions - except the base will not be flat due to the short sides of the rectangle being on top of the long sides, to make a small gap. Then I'm going to join the two with four metre-long aluminium angle extrusions, thus creating a cuboid. I'll lap-join a few strips of angle across the long edges at corresponding heights on both sides for resting platforms on.
Then I'm going to bolt clear plastic sheeting onto it, with one long side mounted with hinges and a latch for access. The platforms will be wooden. The bottom will be a removable plastic tray.
Anyway, I've been experimenting with using flux coated "aluminium repair" rods to join the stuff together - takes a bit of getting used to the melting points of it and the aluminium; I have a few droppy bits of aluminium offcut and some corroded messes, followed by a few really nice shiny fillets! All this done with a GoGas butane/propane mix blowlamp and some patience. After actual engineer friends told me that joining aluminium was too hard for an amateur to master and I should just spend more on easier metals to work with. Hah.
Hmmm, brazing is fun - I've been experimenting with a Microflame torch, too, and normal silver solder and flux, on 'proper' metals. Built a little model artillery piece for my girlfriend's father who is a militaria buff, which I'm about to pickle and paint, as an exercise (so it also has some lumpy joints...).
My book (Tubal Cain's "Soldering and Brazing") heartily recommend a gas / air torch (the kind with an air pump rather than the kind that sucks air into the gas stream) because you can adjust the flame without swapping nozzles - but nobody seems to sell these things! Have they gone out of fashion? Can anyone recommend a UK supplier, either mail order or in the London region?
Ho ho! My girlfriend would kill me :-)