Time to prepare the spar for the 4 plys of UNI… the outer sheer web.

Usually you just add a thin coat of micro and then the first layer of cloth and off we go. There is also a technique called hardshelling that I use sometimes. In this case the foam has a few small dings and where some epoxy got under the masking tape and after all the sanding some foam areas need more than just a wipe in preparation. You can see this in the first pic.

Pic 2 has me doing a standard micro fill on one side. I let this cure and then did many hours of careful sanding. Next step was to ensure no shiny areas in the low spots and then another fill with very thick micro. After that cured I did another sand. Then another light fill in a couple of areas. Then another sand.

Then turn it over and do the other side

This took a few days and you can see in pic three after a fill and before another sand. The spar is now in pretty good condition and had a nice dull surface, pretty smooth ready for the UNI sheer web layup.

Spar foam needs a fill

Micro fill

More filling