Wet sanding, what am I doing wrong?
 

I have two different boats that I have brought the gel-coat back from the dead but I am not happy about the small sanding swirls that I left behind.

My problem is that after wet sanding the boat using three different grits I still have sanding swirls that I can’t get out.
I started with 600 then 1000 and now 1500 but I still don’t get the results that I am looking for. What am I doing wrong?

What is the correct way to sand a boat without damaging the gel-coat, leaving swirls and or wasting time and energy?

Make sure you completely remove the previous sanding marks from the gelcoat before moving to the next highest abrasive. You may need intermediate papers such as 800 and 1200 when moving in between grits as 600 to 1000 will take quite a bit of work removing the sanding marks. Also make sure you are using quality paper because if a piece of abrasive breaks free and stacks upon another you will get pigtails on the gel. Lots of lubricant will also help clear built up gel youve removed

An interface pad(small cushion) will also help making sure the pressure is even across the pad face as well. It goes between the paper and the machine.

Opps double post.

Do I use plain water or is there something else I need to do? How wet does the area need to be when I am sanding?

One good squirt of soap and rest water. Let the paper soak in warm water for 20 mins or so before use as well. The area should be as wet as possible while still providing cut if that makes any sense. What type of sander are you using?

I always use soap with the water. I think dish soap (dawn) is the best. Never to much water if the paper dries its swirl time. But what I do that you haven't mentioned is I finish with a buffing compound on a polisher. Many different brands out there. I read on a post from glassdave that he uses fountain of youth. It will be what i use at the end of the season I used to use 3M.

I am sanding either by hand and or using a 3M hand sander the type where you wrap the paper around the half moon shaped block and put the ends of the paper in the slots with the spikes to hold it in place.

The first boat I did was a real faded red or pink in that case but I had used 3M extra cut as the compound with good results and then the second one was teal and black but I had used the Fountain of youth with nearly identical results as far as the shine.

You can see some of what I did with the green boat. I have no problem with the shine just the scratches larger than the polish will handle.

http://www.offshoreonly.com/forums/r...r-project.html

If you get a good polish but still swirls I'd say either use a more aggressive compound first then a finish compound or hit it with 2000 before the polish.

Too much gap between grits. You should go up in 200 grit intervals. You are seeing the deep scratches left by 600 grit....

If it were me I would never have started with 600..... Probably start at 800, then go up in 200 grit intervals until you get to 1200., then go up to 1500, then 2000.