Lemme pass this on about Halekai's information posted above. I printed it out a few days ago because I had to get going quick on a 30 footer with no shine. I got the Dewalt polisher because there wasn't a Makita available locally. I'm real happy with the Dewalt.
I followed his advice for wetsanding, rubbing compound, etc. I haven't exceeded 1000 rpm with the dewalt. I wet sanded with 600, 1000, and 1500. Actually, the boat was already shiny after just the wet sanding. Final results are stunning.
I've prepped old hulls for painting and have done
awlgrip before with good results, but never before have I been able to put a killer shine on dull glass. Not even close. It ain't quick, and there's plenty of elbow grease involved, but it's straight-forward and methodical. By hand sanding and keeping the rpm low with the Dewalt, I did NO damage to the hull and removed only a minute amount of gelcoat. The hull stayed fair as can be...and I don't think I even came close to a burn with the rubbing compound.
Another reason to consider following Halekai's program is that when you're done, you've developed a really solid skill. If you want your boat to be shiny from now on...these are the skills to have.
I'm telling ya, Halekai knows what he's talking about! And by the way, THANKS Halekai!!!