Aluminum Plate....

[Budha]

So I've got some 1/2" 6061 T6 Aluminum plate that I'd like to polish up, once I'm done with some welding. The parts will then be used on my boat - in both fresh and salt water. 

Need some recommendations as far as procedures, products and upkeep go.

The 6" x 36" and 12" x 36" pieces will be whole, so could I use my PC for it or should I go with the wheel(s) on a drill or a combination of both? Once it's installed on the boat, it'll be harder to access it with the PC.

What products or kit should I go with? Is there any way to 'seal' or clear coat the alum after it's polished to help keep it shiny?

[Too Stroked]

Having formerly worked in a plating shop, I can safely say you're going to have some, uh, fun. You see aluminum is relatively easy to polish up, but keeping it looking that way ...

But let's start with polishing. You'll find that you can make much faster progress with a rotary. Sounds like your drill is the closest thing you've got though. Be prepared to go through lots of pads because aluminum is a real mess to polish. Any good metal polish will do though.

Why didn't I go into any depth on polishing? Because salt water will astonish you with how quickly it will oxidize a polished but otherwise unprotected aluminum surface. You can literally watch it happen.

So what would I recommend? I'd suggest a bare minumum of a clear rattle can paint job, but that won't last very long either. The best thing is powder coat (with proper pre-treatment) or anodizing - preferably hard anodizing.

[Blown F-150]

I can only recommend what I've had luck with on Aluminum. I have no experience with salt water though. I was pretty polish crazy with all my sleds and their bare aluminum tunnels needing to be polished. I used a jewelers wheel on a drill (approx 4" wheel). I found it worked a lot faster then hand and you could get it to a near mirror finish. As Tom has mentioned, a rotary would be best for that nice flat metal. I am a huge fan of the regular Mothers metal polish in the little tub. I would think that and a wool pad, you would be done in no time.

I have no idea on keeping it shiney with the salt, although I like the idea of the clear-coat.

Any ideas on aluminum wheel sealant???
 

[Budha]

I don't know if I want to go through the cost or trouble of having it anodized. Did some looking around and found some marine grade clear coats out there that I may try. I have a gravity fed sprayer I can use.

I'll look into the polishes available at the local AP stores.

[Too Stroked]

Here's a little hint if you do spray it. Get rid of any external sharp / square corners if you can. Paint naturally runs away from them leaving you with some very thin coverage.