This article is in response to a question from one of our visitors. She wrote:
I have an Airstream camper and I would like to know what is the best for cleaning and polishing exterior Aluminum.
Aluminum is great. It oxidizes which actually protects the metal beneath, unlike iron based metals which will rust all the way through until there is nothing left. I had no idea how dramatic the before and after photographs where, until I look at one website.
Here is one of the antique (1964) trailers that they restored:
There are companies that actually refinish these trailers, but I almost wanted to switch professions when I found out what they charge! It costs $100 per foot!! (Including the bumper in the measurement)
So your 25 foot trailer will cost $2500 to restore! Yikes! No wonder you asked us! You can probably do it yourself, but expect to spend the first two weeks (80 hours) of your vacation, and a couple hundred dollars in supplies to get similar results.
The first thing you need to determine, is if your trailer has a clear coating on the aluminum. This would have been applied after, as it was not included in the factory finish. The clear coating is good and bad. It is good because it protects the aluminum, to keep the “new” look for three or four years, until the clear coat itself begins to haze and dull. Then it becomes bad, because there is no way to polish the aluminum that is covered with this clear coat of paint, and there is no easy way to remove the paint, either. If you find your trailer is clear coated, you will need to source out a professional company to help you.
How do you know if it is coated? Buy a metal polish (I like Maguire’s) from your local automotive detailer. It is usually sold in small tins for refinishing aluminum wheels. Using a clean, dry rag, rub a little onto the surface of your trailer in an inconspicuous spot. Continue rubbing, and if there is no clear coat, the rag will begin to turn black. Continuing buffing with a fresh clean dry area of the cloth, this surface will polish to a brilliant shine. If it is clear coated, the clear coat may look cleaner, however the rag will not turn black.
So now you have a six inch circle polished on your trailer. Look at how big your trailer is. Do you have the gumption to attack this your self?
You can make it a bit easier on yourself, buy buying a good quality orbital auto polisher. Not one that goes in your 12 Volt automotive outlet, but a powerful 120 Volt unit. A more aggressive polishing wheel for a drill or angle grinder will speed up work, but these can also cause damage to the metal if you are not careful.
The first step is to wash the trailer thoroughly, and rinse it off very well. With the polisher you will need several different application and buffing bonnets. You can probably easily attack a 3 foot square section at a time, applying the polish with the first bonnet, and continuing to change the bonnet when they become soiled. I expect it would take at least half a dozen bonnets for each section, and likely an hour or so to complete one 3 X 3 (9 square foot) section. The bonnets can be laundered, however the heavily soiled ones may not clean very well.
Once you have polished the whole trailer, I would apply at least 2 coats of quality automotive paste wax, buffing after each coat, to minimize the damage from the elements. If your trailer is not as badly oxidized as the one in the photo, you might be able to get away with a less abrasive liquid metal polish (which is often marketed as a stainless steel polish). Check with a janitorial supplier. The liquid will be creamy or blue, and in a spray bottle (NOT an aerosol can). DO NOT use a greasy clear petroleum liquid found in aerosol spray cans (and marketed as stainless steel cleaner) it WILL NOT WORK!!!
If you do undertake this big job, I hope you will also find time to go camping this summer!