So much sanding to get that glossy finish.

So much sanding to get that glossy finish.

May 9, 2019 0 By Michael

With the epoxy finally cured, it was time to do the finishing top coat. To prepare for this we needed to do a lot of sanding. I used Diablo sanding discs with my Dewalt orbital sander. The top coat I used is Minwax Spar Urethane. It is designed for outdoor use and it will protect the epoxy from UV rays, while providing some additional water resistance.

Teardrop after the epoxy cured.
Teardrop after the epoxy cured. It looks great from 20 feet away.

The below image shows just how many runs were in the epoxy. I’m not sure the runs could be avoided since the surface had to be vertical. This is after sanding with 80 grit sandpaper.

Runs in the epoxy showing up after the first round with the sander.
The runs in the epoxy were really visible after the first pass with the sander.

I ended up sanding the entire trailer in steps. I started off with 80 grit and progressed my way to 120 grit, then 150 grit and finally sanding with 220 grit.

The 80 grit sandpaper:
120 grit sandpaper:
150 grit sandpaper:
220 grit sandpaper:
The sander I use:

sanding progression, finer grit on left vs right.
sanding progression, finer grit on left vs right.
Complete side sanded down to 220 grit. This time consuming step will make a great finish.
Complete side sanded down to 200 grit.
So many dead sanding discs
I went through so many sanding discs.

After sanding everything down it was time for the spar urethane finish I was using for the top coat. Which is Minwax Helmsman Spar Urethane in Clear Gloss.

the sanding payed off, the spar urethane finish is bringing back the shine.
It was so nice to see the shine come back after sanding it away.
the finish is so shiny
This is the front of the trailer after the first coat.

The trailer ended up with three coats of the spar urethane finish. I think all that time consuming sanding payed off as the finish came out pretty well. I could go back and hand buff the finish farther, but I figure the trailer will be subject to all sorts of debris hitting it on the road.

side shot after the spar urethane finish went on
Loving the shine, after all that hard work. The blotchiness up front is sawdust.