Restoring gelcoat damage from sanding

[dimnddavid]

My boat had at least 15 layers of paint on it when I bought it, so I thought it was time to strip it all off and start fresh. I'm doing the final sanding before priming with 80 grit on an orbital sander. The problem is that I accidentally hit a few places with the sander near and above the waterline where there isnt going to be any paint. Needless to say, the resulting gelcoat is rough in texture with no gloss. My question is twofold:

1. Is this gelcoat now more susceptible to water intrusion since I can only assume that removing the gloss makes it more porus?
2. How can I restore these sections of gelcoat? Wet sanding? Some kind of sealer? I know it is beyond just a polish and a wax.

I have a third semi-related gelcoat question:
3. I got some light brown burn marks in the gelcoat from removing the old name on the stern using the 3m wheel. What (if anything) can be done to remove those light burns? I've tried polishing compound, rubbing compound, and some other hull cleaner that smelled like acid and nothing has worked so far...

Thanks in advance for any advice!

 

[390x]

1. You should still be fine
2. Wet sand with 220, 400, 600, 800. buff with Presta SuperCut to original shine.....if there's enough gel left.
3. Unless the burns go really deep, you should be able to wet sand and minimize the burn effect. This is why I don't like the eraser wheels.

 

[dimnddavid]

Thanks for the advice 390! I haven't seen anything by Presta locally in stores, so I guess itll be an online purchase. Does $29.99 for a 32oz bottle of this stuff sound reasonable to you?

 

[390x]

Thanks for the advice 390! I haven't seen anything by Presta locally in stores, so I guess itll be an online purchase. Does $29.99 for a 32oz bottle of this stuff sound reasonable to you?

I like this price better. :grin:


http://www.foxruntools.com/search.aspx?find=presta+super+cut

 

[HUMPH]

Thanks for the link! Never use 80 grit sandpaper on gelcoat! You could have used a chemical stripper for removing paint that someone used on fiberglass for some reason. I agree to use less aggressive sandpaper but start with 600 grit and finish with 1500 or even 2000 grit. Be careful since the gelcoat isn't very thick. After sanding I agree completely in the Presta product. Use the instructional videos on their website and do a small area at a time. When finished use their pro polish to seal and you are good to go unless you like to add a wax on top. Presta will tell you which pads to use for each product as well.

My boat was pretty oxidized when I bought her and tried several products before using Presta and now she finally shines like I want as you can see in my signature picture. Good Luck and take your time!

 

[dimnddavid]

390X- Fantastic price, I'm glad I asked!!

HUMPH- I actually did use chemical stripper to remove most of the paint, but the primer stayed on in most spots, AND it turns out the gloss was never taken off of the original gelcoat. I'm putting the interprotect barrier on and I thought it said to remove the gloss with 80 grit. I'm being careful and doing well everywhere, except in those small spots where (and now I'll come clean) my friend hit above the water line. He was giving me a hand for free so I don't complain about a few mistakes here and there! :smt001 I'm looking forward to trying out Presta; your boat does look exceptionaly shiny in that picture!! Thanks again.