Windshield frame repair
A little history - I bought my camper back in 1988 near San Diego. At that time, it had a very small amount of rust underneath the windshield, as is typical of baywindow busses. For the next eight years I stayed in San Diego and despite living near the ocean much of the time, the rust underneath the windshield (and minor rust in other typical places such as the battery tray and front seatbelt anchors) did not get significancly worse. Then in 1996 I moved to Dallas, Tx.. Much to my suprise, within months of moving the rust underneath the windshield began growing and spreading to the point that it required my immediate attention. I would say that within six months of moving to Dallas, my bus rusted more than it did for the entire eight years in San Diego. My theory is that high humidity is more responsible for rust than rainfall or a salty ocean breeze. I won't dispute that salted winter roads are the number one cause of rust, but I believe that humidity is the number two cause.
In any case, over the next couple of years I ended up making three serious efforts to stop the rust, each time removing the windshield, taking the sill down to bare metal, sealing, primering and repainting the surrounding area. The first two attempts came up short but I think I finally got it right the third time because there has been no reoccurance of rust for several years now. Following will be a description of the three different attempts and what I have learned from them.
No pictures for this attempt, which was made around the Spring of 1997. I removed the Windshield and stripped off the paint and rust using power sanders, grinders, and wire brushes. I applied some Duro Rust Converter similar to this linked product (the white milky stuff that turns black when it comes into contact with rust, available at Home Depot), then RustOleum primer, then white RustOleum paint. I replaced the windshield and was very happy with the results until about three weeks later when I noticed a small rust bubble had already appeared at the edge of the rubber seal. Three weeks was not as long as I'd hoped the repair would last.
The thought of taking the bus to a professional body shop and paying big bucks to have the sill cut out and replaced drove me to try the repair again in the Spring of 1998. I had heard of a product called Corroless which was similar in function to the Duro Rust Converter but it was more expensive, of thicker consistency and colored a dark red. According to the Corroless folks their product is used on drilling rigs in the ocean and if it can protect metal in that environment it can handle my window sill. Worth a try - I ordered a pint from Eastwood Restoration for about $20. Once again, I removed the Windshield and stripped the sill down to bare metal. This time I decided to remove ALL the rust despite the claims of most rust converters (including corroless) that it isn't necessary. There was heavy pitting in several places so I used a power wire brush to clean those areas up. In the most hard-to-reach places, I took out the dremel and used it's tiny wire brush. This turned out to be a bad idea. Not only did the tiny wire brush not work very well, but pieces of the wire broke off and imbedded themselves in my face. This folks is why you should always wear safety goggles - I don't want to think about what pieces of wire stuck in my eyeballs would feel like. Well, I couldn't get all of the rust out with the power wire brush so I bought a cheap sandblaster at Wal Mart and attempted to sandblast the sill. This extra-low-buck sandblaster (I think it was about $20) did not want to work and it took plenty of experimentation before I finally discovered the key - gravity-feed. I strapped a big funnel to the top of a 6ft ladder and hooked it to the sandblasting hose. Filled the funnel with sand and away I went (please stop laughing, I do not claim to be a professional body repair person nor do I ever want to be). One other thing I discovered, so-called "play sand" doesn't work very well - I bought some coarse media at the local True Value (RIP) that had very sharp edges and took paint and rust off many times faster than the play sand. After I was finished cleaning up the window sill, it looked like this:
Next I applied two or three coats of Corroless, per the instructions. I like the way this stuff goes on, more like a thick oil paint. It also dries to a much nicer surface than the Duro Rust Converter. Very smooth and hard, reminded me of manzanita bark
I then primered and painted the sill as before:
A month passed and no rust bubbles. I threw the Duro Rust Converter in the trash. Two months, still good, and I was ready to claim victory. Unfortunately, sometime around November 1998 (six months later, approximately) I again saw rust bubbles forming at the edge of the seal. Words cannot express how disheartened I was at this point. As the weather was turning cold and rainy, I decided to wait until Spring to tackle the job again. This gave me plenty of time to think, and time to think is something I desparately need in order to make good decisions. I ended up thinking about it for a whole 'nuther year in fact.
In the interim I picked up a Craftsman sandblaster. Still a pretty low-budget unit but better than the stick-in-the-sandbag one I had. Even with this unit I still had better results sitting it on top of a ladder. I was fairly certain that I had sealed the sill well on the previous attempt so I made up my mind that there had to have been some rust and/or moisture underneath that led to the reoccurance. The pitted areas in the past had been difficult to clean well. This time I decided to get the sill surgically clean before applying anything. I also learned about self-etching primer and bought a can to apply to the bare metal. In April 2000 I decided to tackle the job again. I removed the Windshield a third time.
Unfortunately the rust had had enough time to eat completely through the metal over the winter and I now had several small holes in the sill.
Back to the store for a can of Bondo (I know, many people don't like Bondo but I believe it can be made to work under the proper conditions). I removed the loose rust with a paint scraper, then used an electric grinding wheel to take off as much surface rust as I could. As before, the heavily pitted areas did not respond well to this. I started sandblasting again and noticed something new - if I stayed on the pitted areas, eventually (like over the next ten seconds) the sand would dig the rust out of the pits and if I continued to hold the nozzle in the same spot, the surface of the metal would turn grey and take on a rough consistency. I had not left the nozzle in one spot long enough for this all to happen on the previous attempt. It took quite a while but I did this over the entire surface of the sill until it was all a uniform gunmetal-grey color without a single spec of rust. At this point the metal looked like it had been dipped in acid - very confidence-inspiring.
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Next I applied a couple light coats of the etching primer ($15/can). |
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| Then a few coats of Corroless. I got the Corroless from Eastwood Restoration. They do not appear to sell Corroless anymore under that name, but their Rust Encapsulator looks suspiciously similar. |  |
Once again that nice smooth manzanita bark coating - love it. A little bondo to fill in the holes...
Followed by normal primer and paint.
Finished product. As of the time of writing (Sept 2002) I have not seen any evidence that the rust is returning.
