Sanding the Topsides Primer & Spot-Fairing

November 11, 2019

Arriving back in town in the afternoon, I was able to get onto the boat by 2:30.  My focus was to get the first two coats of Alexseal Finish Primer sanded, so that I could spot fill the many small voids that suddenly were [more] visible due to the paint application.  

I started at the port side bow, using 9" X 12" sheets of 100-grit sandpaper cut, quartered into more manageable sizes.  

I "cut-in" along the tape line (aka waterline), and then worked my way up to the sheer line.

The primer is extremely durable, which is good for the durability aspect of the topsides paint, but tough slogging for the hand-sanding human!

At the conclusion of the sanding, I brought out my small pancake air compressor, and then blew out off the sanding dust.  I made sure that I covered the surface with the compressed air so that the small voids would also be revealed.  

I then wiped down the surface with a solvent to remove any remaining sanding dust, and there was enough to certainly warrant this task.

Retreating to the shop, I mixed a smallish amount of the TotalBoat TotalFair epoxy fairing compound.  The two-part system contains a soft yellow paste and a blue, mixed together thoroughly catalyzes the epoxy, known when the yellow and blue turn to green, and remains soft (in Florida) for a period of ~15 minutes. 

I slowly worked my way around the boat searching for and filling the pinhole voids.  I did this by hand, simply pushing the fairing compound into the voids and ensuring that there was enough standing proud of the surrounding surface to then sand back fair.

I finished at the aft port quarter.  It is amazing how many of these small voids were revealed with the grey primer paint applied.  The topsides were far from uniform in color palette after sanding, and the made identifying the voids nearly impossible.  The first two coats of primer served as a great base, but also served as a way to see these voids.

I finished the evening by fairing out the recently fiberglass reinforced Torqeedo motor mount.  I had recently completed the angle of attack for the motor installation, that is setting the mounting pad so that the propeller pushed water at a slight downward angle.  As part of that adjustment, I wrapped the exposed portion of the base in 1708 biaxial and 10oz fiberglass cloth.  Once I had sanded the surplus cured fiberglass from the motor mount, I then needed to come back and fair the weave of the cured fiberglass.  I did the fairing this evening, and purposefully over applied the West System epoxy fairing compound slightly to ensure that I could hand shape the final product and be ready for the next round of primer paint.

Total Time Today: 3 hrs