The Gelcoat Finishing Process

Why I charge $125 to finish tank and tail

When special color body parts come out the mold they are "rough". They will have a pebbley surface, scratches, pits, and mold irregularities. Sometimes the gelcoat is thin and the dark matrix under it shows through. Either you or I have to make it smooth and shiny for graphics.

Here is how I do the finishing (it takes about 3 hours)

A tail with black magic marker used as a sanding guide.

I cover all the gelcoat with a fat black magic marker. That is my sanding guide. With 2000 grit I wet sand until all the marker is gone. Always, scratches and pits remain. I sand these points even more, guarding against sanding all the way through the gelcoat, but it does happen. For stubborn scratches and pits I use a Dremel tool to grind down below the problem. Then I mix up matching orange gelcoat and fill the little problems. Sometimes they are as small as a dot at the end of this sentence. After they cure 6 hours later, it's sand again until no trace is left of them.

In the case of the tank shown here, the gelcoat was thin on one side, and if you looked closely you could see the dark matrix underneath showing through oh so subtly. I had to spray the whole side with a layer of orange Preval gelcoat with a Preval sprayer. Then the sanding process starts all over again.

Often this fill/cover/sand process occurs three times. After I polish with 3M Finessett II micro polisher, flaws will appear that couldn’t be seen in the sanding stage. Then it back to fill, sand and polish again.

The whole side of this tank was thin and the dark matrix underneath was showing through in a subtle way. I had to spray a layer of orange gelcoat over the entire side and sand it smooth.

I am perfectly happy to not charge you for this process if you want to do it but I suspect you’ll want to avoid it. When it comes to filling in orange gelcoat you won’t have the material on hand. Sure, I could send a small bottle which would come a week later.

When the body parts are perfect I apply the graphics. If I screw up here I’d have to buy a replacement sticker at my expense. If you screwed up you have to buy the sticker at your expense.

When you get right down to it, I’m still cheaper than painting. I charge $125 for the color upgrade and $125 for finishing. Where are you going to get a good paint job for less than $250?

  • [Site updated August 19]