Looking for tips on wet sanding. - UPDATE

[bjanakos]

Sending out a feeler here for anyone who wet sanded an F-32 to get an idea how the gel responds to sanding.

I am re-naming and re-lettering the boat. I spend the entire day yesterday removing the old lettering and adhesive.

The letters on the bow left behind a well defined yellow stain. They seemed to fade slightly when I hit it with compound by hand, I may be able to rub these out with a rotary buffer.

The letters on the stern not only left behind a yellow stain, but are also somewhat raised. I am probably going to have to sand this one out and if not take it completely level, at least feather the letters down. If I were restoring a finish, I usually start with 1000 grit and work backwards to 800 if I need it. Then upwards again to 1200-1500.

[mikeandanne]

Why not try that acid you were talking about before to clean the gel much like bleaching...dont know if this would work but worth a try.....reason is in my opinion with these old boats you have no idea how many times they have been buffed and you end up with no thickness of gel left, the only time I would wet sand gel is if it was prep for painting.

I had much the same as what you are seeing and we just polished it a lot, put the new name on , it has evened out to the point you can only see the old in certain light....Mike

[Big D]

The raised areas from the old lettering is not easy to get rid of without affecting the lower areas of the gel there. You can try the 1000 but you have to be very careful not to cut through the lower gel areas. Rushing this will cause a worse problem than raised lettering but it canbe taken down to a point where it should barely be visible unless you were really looking for it. Then polish the whole area to even out.

[prowlersfish]

I removed the decal from the stern and used acetone to clean it up . Then I wet sanded it came out very well . On my bow the number where painted on I just wet sanded them , again it came out well .

[Barrie]

When sanding wet or dry, if you are concerned about only removing the high spots make sure to us a hard backer. I use a 1/2 thick rubber pad with the paper wrapped around it for areas that have contours and are uneven
If I want to level out and not hit the lows only the highs I use hard plastic or plexi glass.
I do this often to remove painted pin strips on cars , or the raised area left behind from peeling the vinyl off.

Of course the boat name is a lot larger of an area, same principal I guess.
If using plexi I would use 800-1000-1500 then buff. You could likely skip the 1500 and buff after 1000

[bjanakos]

Why not try that acid you were talking about before to clean the gel much like bleaching..

The acid interacts with the oxygen molecules of the oxidized gel, wax, and calcium in the hard water deposits; It will not remove gel. If left on too long at a high concentration, it will leech through the gel coat to the layers underneath, releasing heat and gasses and causing bubbling.

[bjanakos]

I removed the decal from the stern and used acetone to clean it up . Then I wet sanded it came out very well . On my bow the number where painted on I just wet sanded them , again it came out well .

Were your letters raised? I am thinking that was caused by decades of the sun beating on black decals and the added heat expanding the gel underneath it.

[Big D]

I removed the decal from the stern and used acetone to clean it up . Then I wet sanded it came out very well . On my bow the number where painted on I just wet sanded them , again it came out well .

Were your letters raised? I am thinking that was caused by decades of the sun beating on black decals and the added heat expanding the gel underneath it.

You'll get that with any colour decal even white. I think it's more likely from polishing and scrubbing. Every time you polish, you remove a little gel. The letters stay raised because you can't polish the gel under them.

[bjanakos]

I spent a day working on the hull because the lettering guy was ready to go. After removing the old letters, I prepped the surface with 600 grit wet sanding followed by 1000 grit. After several washings, I followed up with 3 passes of a heavy cut compound, then 1 pass with a medium cut. I did this on the transom and the forward areas that will receive the new lettering. I think the rest of the hull will buff out nicely with 1 pass of compounding followed by wax.

I did the lettering design myself which is adapted from some of the earlier comic book episodes. I am very pleased with the results and I think the red really POPS!



BEFORE



AFTER

[1967 seavoyager]

Don't forget the Denaming & Renaming ceremonies so Neptune doesn't get mad & drag you down to Davy Jones's Locker.

[jimbo36]

I removed the decal from the stern and used acetone to clean it up . Then I wet sanded it came out very well . On my bow the number where painted on I just wet sanded them , again it came out well .

Were your letters raised? I am thinking that was caused by decades of the sun beating on black decals and the added heat expanding the gel underneath it.

You'll get that with any colour decal even white. I think it's more likely from polishing and scrubbing. Every time you polish, you remove a little gel. The letters stay raised because you can't polish the gel under them.

The amount the gelcoat that is raised, following the removal of the letters, is an indication of how much gelcoat has been reduced over the years. This will give you an idea of what gelcoat thickness is left. Edges and corners will likely have less gel left as buffing tends to remove move gel in these areas. The yellow stain will fade when exposed to elements. Also, what is obvious on the hard is often hard to see when the boat is in the water.