Best grade of sandpaper

[jtrom]

I have an old fiberglass boat that is BADLY oxidized. I'm gonna do the wetsanding/buffer polishing process to make her shine again. What is the best grade of wet sandpaper to use to cut the oxidation?

 

[Chris1956]

Re: Best grade of sandpaper

You need to use the finest you can find. It wll be slower to bring out the shine, however, you do not want to sand thru the gel coat. I wouls start with liquid sanding compound, and it that doesn't make it, try 2000 grit sandpaper. Sand as little as possible. If you go to far, prep as for painting and spray or roll and tip.

 

[JB]

Re: Best grade of sandpaper

To shorten the job I usually started with light going over with 800 wet, then went to the 2000 wet.

 

[Fed up]

Re: Best grade of sandpaper

When I did mine i started with 800 grit and a cordless drill ( a head light restore kit has the nessary attachements. The went to 1000 on a sanding block, buffed with course buffing compound, then fine compound, cleaner wax, then polishing wax...

All sanding was done wet, makes a big mess but saves on paper, keep a towel handy work it a bit then dry it, after the 800 pass it will be dull, shoot some water on it and see if it looks smooth and shiny. If it does step to the 1000, work that until it likes just a bit dull after it drys, then the compounds.

It will take a while, try it on a sort of hidden area first, you will get the hang of how many passes it takes to make it come out even.

 

[hlhneast]

Re: Best grade of sandpaper

I just started working the fiberglass hull to remove the oxidation. A buddy suggested 3200 grit but I picked up some 2000. I am thinking that it would be better to start with a coarser grit as suggested above starting lightly and then working the 2000. I am actually using an almost perfectly sized grouting trowel as a sanding block. Just wrapping the paper around and taping it on the backside. This provides a nice flat surface with a rubber backing and a handle!

 

[5150abf]

Re: Best grade of sandpaper

The fewer steps the better as you take off material with every new grit, I would follows JBs advice and go with 800 then 2000, keep in mind that one you go through the gel there is no way back so go easy.

I would do a test spot toward the back bottom and see what the least amount of sanding is you can do ,definately don't do the entire boat at once, if you go too much you will screw up the entire boat instead of one small area.

When I wet a car I will sand for a bit, wipe it off to see where I am sand more ect, check and check often and there is no fast or easy way to do this so take your time and it will look really nice when you are done.