aluminum vs. steel for stand

[rxinc]

Has anyone actually used aluminum for their stand??

I talked to a fabricator today who is going to run the numbers, but he thought that there would be

- more cost for the material ( alum. = ?, steel = 300.00)

- same price for labor ( about 400.00)

- but then no powder coating ( save 200.00)

and obviously lighter weight,
and ability to drill into it affix the wood skins w/o ever having rust.

Any reason beside poss. cost NOT to use aluminum. Thanks - Fred

 

[jtemple42000]

aluminum + salt = not good

You will have to be sure you keep salt off of this aluminum stand. It will oxidize like crazy if you do not. How big of a tank is this for?

 

[rxinc]

How big of a tank is this for?

How big of a tank is this for?

215gal. 3/4 in. glass, being made by Oceanic 72x24x29H

 

[jtemple42000]

I have no experience with this type of setup, however I'm not sure that aluminum would be the best choice. Simply because of the reaction you get from aluminum when it comes into contact with salt. I think that you would be ok short term, but I'm not sure how it will hold up down the road.

 

[AD91158]

Actually aluminum is better because it will not corrode as easily as steel will. Aluminum does oxidize (corrode) however it does so at a MUCH slower rate than steel. Also aluminum would not have to be painted to provent corrosion unlike steel. Aluminum is a very difficult metal to weld, requiring a hot fast weld. Most professionals have 6 or 7 years of training to be profecient at welding aluminum. Aluminum is used in the boating industry alot, so i see no problem with using it to build your stand.

 

[jtemple42000]

It may be used in the boating industry, but it is coated to prevent corrosion. Paint, primer or something. Airplanes are constructed of aluminum. Airports do not use salt as a deicer because of its corrosive effects on aluminum. In guess what I'm tring to say here is that if the aluminum stand is used it needs to be protected.

 

[Fiziksgeek]

They tried making car bodies from aluminum back in the day. It was a horrible failure, especially up here in the Northeast where they were exposed to salt during the winters.

If left uncoated, steel will rust of course and the aluminum will corrode. You could always try titanium, thought that expensive. What about stainless?? Of course, when you weld stainless its not really stainless anymore, so you will get corrosion at the welds...I would suggest powder coated steel.

 

[AD91158]

jtemple, your right it is coated, well actually plated with chrome. However this is only for aesthetic purposes. When steel begins to rust the elemental iron in the steel Fe reacts with oxygen in the air to form Fe203 aka rust. When aluminum corrodes it reacts with oxygen to form aluminum oxide, a very hard compound. Aluminum oxide is so hard it is used on grinder discs to grind other metals like steel. Not only that, but aluminum oxide adheres very strongly to aluminum unlike rust which evcentually falls off of steel. Salt water only accelerates the corrosion processes by making oxidation occur faster. I believe your safer using aluminum than steel. Trust me they cast boat outdrives out of aluminum for a reason, steel submerged in saltwater would not last as long as aluminum, even if it were coated.

 

[Aquaduck]

Have the aluminum anodized if you really want to protect it. This will cost you though. The whole stand would need to be submerged in an anodizing tank to do it.

For what it's worth get it made out of steel and powder coat it, much cheaper. Unless you're constantly sloshing saltwater on it the stand will never rust.

 

[flahunt]

You can get the aluminum powdercoated as well. Most of the aluminum railings are powdercoated these days. The aluminum should be a little bit lighter as well. Both aluminum and steel should be coated to protect the invenstment. You can also get a zinc coating to go underneath of the powdercoat for even more salt protection.

 

[mbunaman]

When I used to weld in my classes they stated Steel is the strongest. That is why aluminum is not welded in aircrafts it is not strong enought. If you looking for a coating that will never corrode use Por- 15 paint process. Powder coating is not ideal the reason is if it scratches there is no real way of repairing the scratch. Por-15 takes abuse and is hard to chip. The process starts out with a degreasing, alodine process, primer, and final coat. Also someone stated they had there stand anodized. Anodize is a controlled oxidation to the metal and this solution is tinted to accept the color. That does not offer any great corrosion resistant coating.