Here is the link to EverShield Tech Data Sheet : http://www.nationalsealants.com/Evershield%20TDS.pdf#search='evershield'
I just spent a few minutes with the Deft industrial division this morning - they specialize in military aircraft coatings. They recomended stripping first - the service manual from Airstream secretariat (approx $75.00) can tell you how; it is worth the bucks - a fund of info. - then appling AlumaPrep 33 and Alodine 1200** but without knowing the kind of aluminum on the trailer they would not recomend the finish product. AlumaPrep is a cleaner and brightner restorer of oxidized surfaces. I seem to remember that Alodine coatings while providing corrosion protection will create a blotchie surface. Once I find out the type of aluminum used on my 86 Limited, I'll talk to Deft again and the update this site. Alodine 1001 is a clear finish while 1200 is golden.
A few months ago I spoke to Airstream's corp sales manager and he indicated that they had solved the peeling problem by having Alcoa apply the new coating with a UV protectant componet in the Alcoa factory and then assemble the coated skin at AS.
** there is no such thing as a "clear alodine 1200" coating. Alodine 1200, 1200s and 600 are all MC (multicolor coatings) chemfilms. If you request 1200, you will get a colored coating. If you requested clear however, you will get an alodine 1500
or an alodine 1000 (these are CC, or colorless coatings). Alodine 1200 is very toxic. And,
Alodine 1200 is a Chromate Conversion Coating, which contains hexavalent chromium. Alodine 1200 is intended to provide corrosion prevention when left unpainted as well to improve adhesion of paint finish systems on aluminum and aluminum alloys. Alodine 1200 is also intended for use as a corrosion preventive film for electrical and electronic applications where lower resistant contacts, relative to Class 1A and anodic coatings, are required. Above information is taken from MIL-C-5541E – Class descriptions.
Alodine 5200 is chromate free and is much less toxic than Chromate Conversion Coating. Alodine 5200 is considered environmentally friendly. The Department of Defense approves Alodine 5200 for use for use as a coating substrate only to improve adhesion of paint. It does not provide the corrosion resistance that Alodine 1200 does and should not be used for that purpose. Alodine 5200 is a clear coating only. To our knowledge, at the time of writing this Information Sheet there are no US Military Specifications pertaining directly to Alodine 5200 or non-chrome conversion coatings.
Hope this gives some info you can use. Ernie