metal or wood stand for large tanks?

[alton]

If you are worried about water try Russian Birch. It has twice any many plies as Chinese made plywoods and it is water proof. I think it comes in 5 x 5 sheets though? My oldest stand that I have currently I made in 99 out of plywood sealed with lacquer and no problems.

[Bill S]

Oil rigs are steel. But, it's what they coat them with that counts. Copper works pretty well. Tin, even better. However, Tin is very toxic, and for instance for boat bottoms, only the US Navy and special permitted vessels can use Tin anymore.

Yes, zinc WILL corrode. Just a lot more slowly than uncoated steel. BTW, steel roofing panels are ALWAYS zinc coated before they are painted. It's the zinc that protects the steel, not the paint - the paint is strictly for looks.

Oh yeah, and on big boats, we use zinc anodes to keep other metals on our boats from corroding. They are all electronically bonded together so the zinc gets eaten up first. Water heaters also have a zinc anode in them too. Most people never replace them.

[LoneStar]

Good points Bill.

You know I haven't seen anyone use reinforced concrete for a stand yet. I figured someone in this country has a house they don't plan on moving out of. A concrete stand (done nicely) would pretty cool. You can even do that foo foo concrete stamping/staining to look it more presentable.

[erikharrison]

You can even do that foo foo concrete stamping/staining to look it more presentable.

My cousin does that for a living. Wanna talk about a dirty job...

[moneytank]

thanks for the replys, I think I will end up going with wood (not for sure yet though)
kind of in a hurry to get the tanks up and running to get them cycled. The house should be done by the end of next week. I will then need to get everything out of our old house as soon as possible since the guy who bought it is letting us rent it back from him. dont want to have to pay another months rent for the fish to live there...

[caferacermike]

I've actually seen stands made from concrete and have books explaining the process. You don't have to not have plans to move. You use sheets of plastic on the floor before you begin the process. Most use concrete supports with 8" I-Beams as runners.

Another point about oil rigs is that they do rust, constantly. They have special teams constantly replacing the bits. I can work on the rigs in my trade replacing pipes and make a good living if I so choose. The supports for the rigs are over engineered. Meaning they are sacrificial as was stated. Because of their heft, they begin to rust immediately. When enough rust is accumulated it can actually protect the remaining metals from rust producing oxygen. The difference is that we use thin walled hollow tubing to build stand with. Essentially it will never get to the point of protection without being eaten through.

A problem with stainless is that you would have to use 316L to produce a stainless that won't rust. Many 303, 304, 308 grades contain iron. When you reach 316 all of the iron has been completely removed and you finally reach "medical grade" stainless. Each grade is considerably more expensive. Not to mention the difficulty in finding a good orbital welder for this "soft" metal. Ever wonder why your "good" chef knives rust in your kithen sink? Because they must contain iron to hold an edge. They are typically 304 stainless.

Another good option, albeit quite new, are plastic plywoods. They look very much like wood and work the same way. They are stronger than wood and offer superior break down protection. Wood has been the standard and with some good protection should last a very long time. If truly in doubt, coat it in marine epoxy. You could even go as far as coating it in marine fiberglass, much in the way TexReefer built his 90g tank entirely out of plywood.