Light bar in what sense? A single bar to hold all your reflectors? A light bar that is bent to hold up a pendant? I have many solutions but I don't know your problem :lol:
I've built a few things out of 8020. I've been really tempted to make a stand out of the stuff.
As for lights, I was looking to do a hood on a counter balanced rail so that the big heavy hood could be completely lifted above the tank by a couple feet with little effort.
Probably 2 sets of bar to suspend a giesemann 230+ pendant that's 24" long (shows up as being 30 lbs. fixture). Why 2 instead of 1? It's because there's no center backing on the stand.
so you're looking for 2 "L" shapes poles? The stuff Tony posted is about as cool and tech as you can get Other then that you could get some stock and have someone weld you a nice one and have it powder coated.
Another option is ZeroEdge Aquariums makes a L bracket for mounting lights above their tanks. I bet they'd sell you a few.
You could use aluminum, HD sells square tubing, c-channel, angles, I made my whole light bar out of it, and rivotted together. Had to imagine what you're looking for though.
well the aluminum rack I made above my tank hasn't shown any sign of corrosion, and yes salt water does spray on it (at least my reflectors which I'd gather also on the frame).
Aluminum AFAIK does not rust... the problem comes when you introduce dissimilar metals, i.e. using stainless steel screws and rivets, you basically can make a battery where you have current flowing... then you get corrosion of materials that are "rust proof".
Also, aluminum doesn't last long (seconds/minutes) exposed to air. It very rapidly forms an Aluminum oxide layer. This thin layer is EXTREMELY tough and chemically resistant (sapphire, the gem, is aluminum oxide with a small impurity for color).
The "miro" type reflectors... think they are coated polished aluminum. Coated with some verythin layer of sealant or such. I can take aluminum in the machine shop and polish it super smooth and it ends up looking the typical grey (oxide coating). I speculate that this is why our reflectors actually "pit"