Starting as early as 1958, Airstream dealers offered a clear lacquer coating on some trailers. The coating–officially called "plasticoat," and sometimes mistakenly called clearcoat–was added because the bare aluminum skins were oxidizing so quickly that customers were complaining. In 1961 it became an official option you could have applied to your trailer for an extra charge. In 1964 it became standard on all trailers.
The formula has changed several times over the years, some versions lasting longer than others. But if your trailer was built anytime from the 1960s to today, plasticoat is something you need to understand. If not cared for, it will fail and start to flake off as the aluminum expands and contracts with the heat of the day, and the UV rays dry out the coating, making it brittle. Usually the failure starts on top, like a sunburn. It takes many many years for the sides to peel. With many trailers 1960s trailers (and a few 1970s trailers), the coating has been intentionally removed so the trailer can be polished.
If you still have your plasticoat and want to preserve it as long as possible, you have to take care of it. Airstream recommends regular cleaning and the application of Walbernize twice a year.
DO I HAVE A PLASTICOAT? If you have an older trailer and aren’t sure whether your trailer has a plasticoat, there are several ways to find out. First, take a look at your trailer from a distance. Does it look like it has a sunburn up top? Are there distinct splotches of darker oxidized aluminum and then the rest of the trailer is looking fairly good? If so, you have a plasticoat and the top has failed. This is natural since the top of the trailer gets a lot more UV and heat than the rest of the shell.
If you don't see obvious signs of failure, you could have a plasticoat that is still largely in tact...OR you could have a plasticoat that has been removed. A good way to check conclusively to see which areas have a plasticoat and which do not is to get a clean white cotton cloth and a tube of white (not gel) toothpaste. Pick a few inconspicuous areas of the trailer to polish with the toothpaste, the rag and your finger. Do just a small one inch patch Are you getting black aluminum oxide on the rag? Or is it just dirt? If you have plasticoat in that area, you won’t get any oxide because the plasticoat is protecting the aluminum from your polishing efforts.
