Wet Sanding Question

[David Stotz]

When wet sanding how do you know when it's time to go to a finer grit?

Thanks, Dave

[monstaaa]

guide coat

[David Stotz]

What

[VinMan]

What are you sanding , gel coat?

[David Stotz]

VinMan,
Yes gelcoat. The boat is 21 yrs. old. The deck is supposed to be light grey. Over the years it has yellowed. It was always shiney, just yellow. It would not come back with compound, so this year I decided to bite the bullet and wet sand it. I just finished the first round with 320 grit. The color is back but it's dull and scratched. I'm now going to use 600 grit. How do I know when to move on to 1000 or whatever should be next.

Thanks, Dave

[VinMan]

320 is way too rough to start with , I would have started with 600 or even something in the 800 range. Its gonna take alot to get the 320 marks out. Try hitting it with 800 to get smooth it out a bit then move up to 1200 before compounding.

[sschafee01@snet.net]

I gotta agree w/ vinman 320 is paint prep grit! better move into the finer grits 800 and up. Always start w/ finer grits and then move down in grit #s if your not getting desired results.

[David Stotz]

I started with 600 grit and it would not remove the yellow. I moved down to 320 and now the yellow is gone. Before I did the entire deck I did a small area. After wet sanding the small area with the 320 I went over it with compound and a wheel. I could almost remove the scratches with it, and it brought the shine back. Last night I went back over it with 600 and the results are good. My question was how do I know when I'm done with the 600 and it's time to move up.

Thanks, Dave

[rv]

Dave,
One trick to help know when to stop and switch to high grit paper is as follows:
1. Start with your 320 in one direction only, when you are happy that the color is how you want it stop.
2. Start sanding with 600 in a direction that is 90 degrees to the previous direction. Sand in this direction only. While sanding you will still be able to see the 320 marks at the 90deg angle. Continue to sand until you can not see any of 320 marks. You are now done with 600.
3. Start sanding with 1000 in direction 90 degrees to the previous direction. Sand in this direction only. Watch the 600 marks and sand until they are gone. You are now done with 1000.
4. Get the polisher with compound and buff out the remaining sanding scratches.

BE CAREFUL there is only so much gel to work with and with 320 it disappears quickly. Once it is gone you will think that yellowed white didn't look so bad!

Rick

[czy40p]

Any recommendations for polishing compounds??