Here is an interesting thread on aluminum boat painting from another boating forum with plenty of pictures.
http://www.riverjetmagaz...VAR_FORUMVIEWTMP=Linear
Some interesting points were made by a very experienced fellow:
1) He doesn’t like chemical strippers. He uses a stripper disk, Norton Avos, on a grinder all over the boat. He then sprays on a guide paint and DA’s the boat with 180 until all the highlighted grinder scratches are gone. Has anyone tried the grinder method on a caked up Marinette bottom? 180 grit is pretty smooth. I wonder if 120 might be better on the bottom if you are going to paint.
2) He says you have 8 hrs to get a primer on after you finish the sanding. That seems pretty long. He uses prep cleaner right up until applying vinyl wash primer. He made a cryptic comment about a sandblasted hull already being mechanically etched and to watch out for pooling which I didn’t fully understand. His theory on how an etching primer works is that is that it flows into and makes a mechanical attachment to “scratches” that the acid makes in the aluminum and then chemically bonds to the following coats. His vinyl wash required a sealer coat.
3) He argued with some other forum members about high build primers for a real smooth topcoat. He says there are some good ones and to go ahead and use them it you want an auto like finish. He also said that he was only going to buff out railings to a high polish. He did not paint the bottom half of the hull or buff it. . The 22’ boat does not stay in the water so no bottom paint.
4) He explained a little bit about paint coat cross linking. That is why with some systems you have to time the coats so carefully once you start painting. He also said you have to understand and rely on the technical specifications of the painting system you choose. Beware of word of mouth. He said he only did one half of the boat at a time to take some time pressure off.
I found it interesting. It showed how to strip a hull with a grinder.
