Making our 1966 Avion shine (but not shiny)

Background 

When we got our 1966 H-24 it had lots of "character". A previous owner tried to polish it and it seems he tried several things. There were polish marks on the top, some of the front and back corner panels had damaged anodizing and he even tried sandpaper on one panel. Further it had an attack of artillery fungus and brown freckles all over and the typical uneven anodizing with runs under the window. I like this patina and the original look and would never paint it but wanted to make it look more even and brighter. Before starting I removed the artillery fungus dimples with plastic razor blades and sealed all the seams with Vulkem 116 and TremPro 635.

The corner panel anodizing is very damaged

Brightening it up 

The 1963 and later Avion models are anodized and can not be polished to a shiny finish like an Airstream (at least not without a huge effort -see link below). Nevertheless the anodized aluminum gets oxidized and dirty over the years and becomes gray and dark. I did some searching how to clean this, for polished aluminum oxidation can be removed with an acid wash. There is conflicting info in the forums if acid should be used on anodized finish, there were some long-time owners claiming they do this once a year while other posts sounded like it would eat the anodizing away in no time. While there were many opinions only few people actually tried it. Since my anodizing was already in bad shape I decided to give it a go. I used Star Brite Ultimate Aluminum Cleaner & Restorer to wash the trailer from bottom to top, I did 2 treatment for about 3 minutes each and about half a panel at a time before rinsing it off. 

The result looked a lot like the picture on the package, the aluminum got a lot brighter. It made the aluminum the was not anodized more dull.  I do not think it damaged the intact anodizing further and I think it can be done every few years to restore the original shine. IT DID NOT, however, restore any of the texture of the aluminum, remove any of the chalkiness and rain stripes.

Left is after Star Brite, trailer is still wet

Front after Star Brite, the tape was for caulking

Sealing it up

After applying Star Brite I sealed all the seams. At this point it was very clean and I waned to wait till the acid treatment was over. Since there were a few steps I write another post for this. 

Making it shine

To even out the surface texture I remembered a trick I learned when I owned a fiberglass Scamp. Instead of the long and painful polishing each year one could just apply a layer of high gloss water based polyurethane. There were 2 products, the inexpensive ZEP Wet Look Floor Finish (yes, this is floor coating) or the more expensive PoliGlow (https://poliglow.com/, also available from amazon). Both are very similar, ZEP might be a bit thinner and is slightly easier to apply while PoliGlow claims to be very UV resistant. I figured that the anodizing or treated aluminum has a similar texture to old fiberglass and this should stick well. I still had the ZEP and started with this but later added 2 more layers of PoliGlow. 

The application is very easy, it is best applied with a microfiber towel, but this should be machine washed 2X to remove all the loose fibers. It just wipes on in a thin layer, basically just wetting the surface. It took me about 30 minutes to go over the trailer, I waited 15 minutes and started again. After 3 layers it really started to look good. This made the surface texture very even the chalky lines did not go away completely but from a distance it looks really good. 

One year later

There are a few myth about Polyurethane coating (see below) but I think it is a really good solution. The trailer has been out in the sun now for over a year and it still looks close to a year ago. The PoliGlow/ ZEP did not yellow at all. It did not come off in any way. We covered the trailer during the winter month and the cover caused some slight scratches but another coating will take these away. I also think that the aluminum is a bit less bright than a year ago but likely much brighter that it would be without coating. 

Debunking some myth about PoliGlow/ ZEP

Strangely the ZEP/PoliGlow method has gotten a bad reputation for fiberglass trailers, as often on the forums this is based on single posts rather on real experience of the people talking. 

- "ZEP will yellow in no time, crack and become unsightly." > I had ZEP on my Scamp for more than 5 years and applied a new layer every fall. During this time it did not become significantly yellow there was maybe a very slight tinge. It still looked very good and did not crack but it was a bit thick after that time and I would have removed and re-applied it in the next years, but I sold the trailer. 

- "ZEP is nearly impossible to remove" > The opposite is true, ZEP Urethane is very easy to remove with a water based stripper offered by ZEP. It basically washes off. This is one of the reasons I like ZEP. People who re-do floor coatings know this. The same stripper exists for PoliGlow. The new owner of my scamp removed it with the ZEP stripper and it came off very well. I accidentally got some paint stripper on the Urethane when painting the inside and it came off within seconds. I believe this myth is based on a single post were someone applied several layers of car wax over the ZEP which then blocked the ZEP stripper.

My Samp before selling 

Other methods to make it shine 

WD40: This will even out the texture and looks similar to the trailer when wet. I am not a fan, it only lasts for a couple of month, rain and sun will remove the WD40 and it will end up in the ground water. I do not like the smell of WD40, and I think it can creep into cracks might smell for a long time, it might also make it difficult for sealant to stick to the seams. 

Owatrol Oil: Similar to WD40 is a penetrating oil and rust inhibitor. It might stick a bit longer and dry a bit better but has the same disadvantages. 

Everbrite and other aluminum coatings (Toon-Brite, KBS Diamond Finish): Everbrite apparently was a dealer option to protect Avions. I think the effect should be similar to water based Urethane, they might lasts longer but these are solvent based and not as easy to apply and remove. They can be expensive.