Sanding gelcoat?

I just want to remove the rough edges away from a light scratch on my hull. Should it be sanded, buffed, or both? With what? Thanks.

not to hijack this thread
but in a similar vein, I got a chip in my boat–a chunk of fiberglass knocked right off of the boat. I assume I surround the area with masking tape then fill it to flush with new gel coat. But where do I go from there? Do you sand it down with the masking tape still on? What grit sand paper should I use? Any ideas on mixing pigments to match mango (where to get them, etc.)? Many thanks in advance!

More info/ Pic

– Last Updated: Jul-15-08 3:28 PM EST –

Tough to say where to start without seeing the scratch.

For legitimacy's sake, I have repaired several hundred gel scratches, chips and worse disasters for Cold Run Canoe, bell Canoe and Placid boatworks.

We usually shape w/ 120 grit dry, then switch to 320, 600, 1000, 1200, 1500 and 2000 grit, all wet. Move up a grit level when all previous scratches are removed. Then we buff 3X with a machine and buffing compound. Good as new!

Your manufacturer should be able to supply w small amount of gel; you can purchase MEKP, the catalyst. in small amounts at most hardware stores.

MiniCraft of Florida has custom mix kits if the mfg can't help.

I don’t need to fill it
It’s not that deep. I just want to smooth the rough edges.

Then start with 320 wet; stop going up the scale when you’re happy.

Passing along what I was told
I have not worked with gel coat but someone who has told me it’s similar to working with “dookie schmutz” (epoxy-wood flour mix), which I have done. You want to slightly overfill the hole so that you can sand it flush and smooth. The mixture should be thick enough to stay put when slightly overfilled.

dookie schmutz?

– Last Updated: Jul-15-08 9:42 PM EST –


Do realize
that depending on the boat and location of the scratch, the gel-coat might be less that 20 thousandths of an inch thick.

If you sand through the gel then you will have more complex repairs to do.

Here’s how to do it
Go to:

and check out my gelcoat and fiberglass repair albums.