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**Jammer** · 09-12-2024, 09:36

Topsides on my boat are showing oxidation. The boat has not been polished or waxed for several years. I plan to polish the topsides myself in the spring prior to launch.

I have available, a 7" high-speed rotary polisher, and a 5" random-orbit sander. I have dabbled in polishing in the past but have never really felt that I got the hang of it.

Realizing that it is difficult to articulate the condition of existing gelcoat over the internet, I would like some general advice on what to expect in terms of time and supplies.

1) General advice has been to use a wool cutting pad with cutting compound followed by a foam pad with a polishing/waxing compound, and use a progression of 400-800-2000 grit sandpaper on the RO sander for particularly bad spots. Is this wise?

2) About how much time should I allow for a 3'x3' area? 5 minutes? 30 minutes? an hour? I have no idea.

3) How many wool pads, foam pads, and backing plates should I expect to use to polish a 38' boat? Do I just use the pads until they fail or is it worthwhile to wash or clean them?

Main focus at this point is topsides below the gunwales with deckhouse and cockpit being a project for another day.

All advice welcome.

Tortuga's Lie · 09-12-2024, 09:49

Your 7" high speed polisher/grinder needs to be variable speed, you need fewer RPM's when polishing as to much speed may burn the wax/compounding paste.
I have two wool pads that I rotate through, when is gets caked a bit, I wash it off, spin it at high speed to get the water out, then switch to the other pad while the first one dries more.

**Jammer** · 09-12-2024, 09:49

Quote:

Originally Posted by Tortuga's Lie

Your 7" high speed polisher/grinder needs to be variable speed, you need fewer RPM's when polishing as to much speed may burn the wax/compounding paste.

Thanks. It is, in fact, variable speed.

rslifkin · 09-12-2024, 09:51

If it's really oxidized you may need to wet sand, but if it's not really bad I'd just start with a wool or aggressive foam polishing pad and some moderately aggressive compound. Start on a small section to get an idea of how quickly and easily it cleans up, as time will depend on the condition of the gelcoat, the equipment you're using, and the compound chosen. If you can't get it shined up well with just compound, then you can try wet sanding, probably starting with 600 grit at the roughest, but you might not even need to start that rough. Wet sanding will remove significantly more gelcoat and is easier to screw up, so I'd avoid it unless you really need to.

Once you have it compounded, then go over it again with a finer polish on a less aggressive pad, then make sure there's no compound / polish residue on the gelcoat and it's time for wax (I typically use Collinite Fleetwax paste and a foam waxing pad on the polisher).