Edwardo,
Here is some information I have collected over the years on refinishing:
Fred Jiran's method:
Sand with 80 grit to remove gel coat
Spray thick coat of epoxy primer
Materials:
Epoxy primer
International Paint YPA851
International Paint YPA853
Mix them 50:50
Spray a thick coat, then sand the ship smooth
Spray with linear polyurethane
Paint: International Paint Interspray 800 YQB000
Hardener: International Paint YQA803
Thinner: International Paint YTA900 series - use 920 if warm
My method as used on my Russia
Primer - System 3 water based epoxy - mail ordered from Washington State - good stuff, easy to use and sand, after 3 weeks it is hard as a rock, environmentally friendly, cleans up with water.
Paint - PPG Concept 800. This is a 3 part linear polyurethane that you can get at any PPG automotive paint store. They also have the 3M guide coat product, which you absolutely have to use. It makes sanding the finish smooth so easy that it is worth 10 times what they charge. The guys up in Dallas at TSA use this paint on their refinish jobs. It is very good paint and very easy to use. In 2005 it ran about $400/gal including the hardener and thinner.
Process per Fred:
Spray 1 gal per wing. Use lots of paint, as lots of it will sand back off. Apply more on the leading edge, trailing edge and wing root. Anywhere there is an edge you need a LOT of paint. It is super easy to sand through with just a few swipes of the paper.
I used a gallon for the whole Russia, but the Russia is pretty small. I did sand through in some spots, so Fred is right about using a LOT of paint.
Sand smooth using 3M Guide Coat as in indicator of when you are through the orange peel. Always use a sanding block. If the surface is undulating, make sure you have enough primer on the low spots so that when you use a long block and sand off the high spots that you can reach the low spots without sanding through the paint on the high spots. In other words, bring the low spots up at least as high as the high spots before they were painted. Use a long stiff block on the primer so that you get a smooth surface to paint on. This will make the finish coat go so much easier and get it to shine right when the sun hits the ship. I made the mistake of not doing this and had to redo some surfaces on the fuselage of the Russia to get it to look good, especially when the sun was low in the sky.
Finish: Fred's method
Wet sand -
400 grit and guide coat - remove the orange peel
600 grit and guide coat - sand at 90 degrees to the 400 grit and remove the scratches
2000 grit and guide coat - sand at 90 degrees to the 600 grit and remove the scratches
My method:
Same as above but I used more grits. I am going from memory, but I think I did 400 - 800 - 1200 - 2000. The finish sanding goes very fast and it is enjoyable to see that beautiful surface appear under your paper. The guide coat will fill in the scratches from the earlier sanding. When you sand with the finer paper, the guide coat will disappear as you sand through the scratches. I keep a water hose at hand and spray the surface to keep it wet and clean.
Set your ship out at 5:00PM on a cloudless day and if you get nice reflections, you know you did it right.
Good luck,
Brian