Here are some of my results:
This is the wash board I started with, the
varnish was damaged from the rain and moisture and it was getting to the wood in some places.
With 120 grit I sanded it down entirely until I got to the wood. My boards are solid wood so I was not concerned about burning through a laminate.
Next, I pooled quite a bit of the clear
gelcoat over it with a brush and let it cure. Pictured here is a particularly bad area where the surface drued before fully curing.
After this, I started the progressive
sanding. 120 and 180 on the random orbital followed by wet
sanding 220, 500, 800, 1200. Below picture was right after 500 grit I believe. Very dull but making sure that it is consistent.
Next step is the rubbing compound. This takes very little effort and you get a nice deep sheen only after a minute or so.
If the longevity of the clear gelcoat is anything similar to the gelcoat we have on
fiberglass boats, I am pretty excited about not having to do this again for a long time and touching it up with a little bit of compound and wax every once in a while.