How to polish/clear coat aluminum?

I have an aluminum radiator that I want to polish and clear coat. How do I do this as far as what polish to use and how to then prep it for paint. What do I do to get the paint to stick? I've never done this before.

 

O.K., I've never done a radiator, but have done many small parts and exterior trim. I use regular ol compound made for polishing paint jobs, and special aluminum polish made for wheels. After polishing with a mini air buffer, I clean the piece VERY well with grease and wax remover and use ordinary clear designed for paint systems. Make sure you clean it well. Like I said, I've never done a radiator with clear, so no promises, but I've painted many engines and parts with enamel designed for the exterior and had no problems. Good luck.

 

Clearcoat won't adhere very long, it'll peel off after a short time. Why clear it anyway? Just hit it with polish when it starts to dull. I don't know anything about polishing aluminum...

Brian

 

Well that's obvious look how dull that canoe is.

 

LOL, I've tried, but if I lean very hard into the buff, and cut the white oxidized layer off, there's this weird cloth stuff...

Brian

 

The first time I polished old oxidized aluminum wheels, I used cotton balls and Mothers on the living room floor during the Super Bowl. I really needed two more quarters to get done.

 

The problem with clearing over bare metal is that it gives it a false finish. Kinda milky or cloudy with a uneven finish.

If I were to do it, I would use a clear lacquere, it is hard and does not flake easly and is easy to remove with lacquere thinner.

 

Must be that new light weight aluminum.

 

...or someone swindled them Injun canoe builders out of their alloy... Probably traded 'em some colored beads and white sailcloth...

 

I use fine steel wool.

Before I bought my compressor, I filed the paint off of this bike:



Went over it with normal steel wool and then with fine. The end result:







It took hours. But, I was curious to see how it would turn out. Now, I just use the sand blaster. Before, I couldn't get into the corners

 

If it is bare aluminum,I'd wet sand it with 8oo grit,then 1000 grit,then 1500 grit followed by 2000 grit. Follow with OOOO steelwool saturated with Mother's aluminum polish. Buff with a soft cotton cloth then apply Semi-chrome polish with a soft cloth and buff with a soft cloth. It will look like chrome.Follow with automotive wax and it will keep pretty good.

Occasional polishing with the OOOO steel wool and Mothers polish will keep it looking fine. Wouldn't use clear coat at all cause it will discolor over time and you will have to strip it to renew the finish.

 

I polished my radiator tanks out with Mother's wheel polish. I wont coat them, as a radiator gets too hot, and I think a coating will either turn color, or come off. Every few months I take a few minutes to hit it if it needs anything.

 

I cleared the aluminum shroud in my '36 with urethane clear after I engine turned it.

I use a product called Bulldog Adhesion Promoter over any bare metal I need to paint, even chrome that I don't want to scuff up. It will make the clear stick and doesn't seem to effect the polish look any.

 

Por15 has a two part clear product designed especially for this and it sticks!

1. Polish the part, no need to get super crazy because the clear will offer some optical hiding.

2. Then clean very well with surface prep, then soap and water. You have to wash it until the water no longer beeds up at all and pay special attention to corners and edges.

3. Mix and spray Por15 clear according to their directions and use common spaying techniques, first a dust or tack coat, let it flash, then hang a wet coat.

Let it harden over night and you're done and will have a tough super clossy part that wont tarnish and will have a hard chip resistant finish that looks great and can take the heat.

 

I'll have to try the POR 15 product... Thanks.

 

It's called "Glisten PC" I'm not a great painter but this stuff levels nicely and makes me look good. It's a bit pricy but worth every penny and a little goes along way.

 

I think "Eastwood " has a clear for polished parts.
I never tried it so I don't know if it works or not ?

 

clear 'lack-a' will yellow quickly as it warms up.

 

Clear-coating that machine finish is great, but the machine swirls give a great "tooth" for the paint to adhere to. The OP wants to clear polished aluminum, which is whole 'nuther thing.

Brian

 

Glisten PC is the best on the market for clear coating polished metal. Many of the OEMs use it for coating those high end polished rims on the newer cars. Adhesion is great and durability is sufficient to withstand the abuse that wheels get on a day to day basis. I buy it by the gallon and get the activator in half pint cans...makes it easier to use/keep over time.

 

The shroud is the only example I had to post... I've sprayed urethane over polished aluminum and chrome using Bulldog several times....same results.

 

X2 on the Glisten pc

I've used it on polished aluminum

 

I pinstriped a Brass T for a gentleman years ago and asked him how he kept all the brass so shiney....he said they counted off for polished brass being clearcoated, so he used hairspray.....said it would wash off with soap and water if he needed to re-polish....just an idea.....I personally havent tried it.

 

I'm not familiar with Bulldog, if you've used it and it works on polished aluminum and chrome (which NOTHING sticks to), then I stand corrected. Did I say how much I like a your machine finished shroud? I really like that finish, and use it, somewhere, on all of my cars.

Brian

 

Thanks for the compliment, Brian. The engine turned stuff is fun...crudely done on my bench with 3M roloc scuff pads...I did the floor boards in my sedan and '36 that way...no clear, though. They "wear in" after a little use and look pretty neat, easy to clean up spilled coffee, too!

The Bulldog Adhesion Promotor is an excellant product. comes in rattle cans or larger quantities.
I thought the same as you till I bought a can about 10 years ago. I sprayed a set of chrome wheels back then and the paint still looked great about 5 years later when I sold the car. It's inexpensive, requires very little material to do the job and lasts a long time...I finally bought my second rattle can last summer.
I use it on a lot of stuff...bare steel brackets that I want painted with minimal film thickness, etc.

It's not a substitute for properly prepared substrates, but for things like polished aluminum, chrome, glass, bare steel, or anything that cannot, for some reason, be prepped any other way, it works well.

 

cool info kids. Thanx! ~sololobo~

 

Go to Lowe's and get some Diamond Brite polish truck tool box polish. I have an old Airstream and have tried em all and it is the best I have found so far. I wouldn't clearcoat it, it will really dull the shine, and could go yellow with the heat off the rad. The initial polishing will take some time, but to maintain it periodically, won't be much effort at all.