June 2, 2019
With some errands to run in the afternoon, I took an earlier start to the boat than I would have on a Sunday. I started with water-washing several areas that I had worked with epoxy in the previous session and previous week: the exterior hull surface below the waterline (applied a sealer coat of epoxy resin to the through-hull patches), the cabin overhead and aft bulkheads, the port forward shroud chain plate knee, and the chain locker tabbing. Today I would sand those areas in preparation for paint or additional epoxy fairing work. First, however, I needed to remove the amine blush from the surface prior to sanding.
With water and a 3M Scotch Brite pad, I scoured the surfaces of the areas described above, and then dried them off with a towel. For all of the areas I worked today - with the exception of tight areas in which I used the 1" belt sander and 150-grit paper - I used the smaller 5" random orbital sander and 40-grit discs. This small sander even with the 40-grit pads doesn't have a beast mode, it is fairly modest in its material removal.
I began the sanding by first tackling the through-hull patches on the exterior hull. I painted each of this faired repair areas with a coat of neat epoxy resin - that is, I applied epoxy resin without any thickening agents. This is an advised practice for below the water line work in order to seal up then epoxy-based fairing compound used (the darker red / brown coloration). In the photo below, the chalky area has been sanded, with just a bit more to go below that area.
I finished the sanding of the four patched and sealed areas, and then directly moved up into the boat to sand the balance of the locations requiring sanding work. I would later, after the sanding was completed for the day, come back and paint out the through-hull patches with a epoxy-based barrier paint.
I moved from starboard aft, up to the bow to tackle the starboard and port sides.
The product used was from TotalBoat called TotalProtect. Similar to Interlux 2000E, the barrier coat is meant to keep water from leeching into the hull laminate and creating "blisters", or pockets in the laminate. The blisters are an acidic liquid formed when water comes into contact with solubles within the fiberglass laminate, further dissolving the material within the laminate and growing in size under pressure.
I could find no evidence of blisters on the hull of this Allied 24, which is likely the result of attentive labor laying up the fiberglass laminate schedule on this boat - one of the first 10 ever built by the Allied Boat Company. The popular notion is that these earlier fiberglass boats were built with the scantlings of wooden boats, and thus overbuilt.
The majority of my time spent today was in a contorted position, moving about the cabin and sanding the overhead in the cabin, the cabin's aft bulkheads, the port forward shroud chain plate knee, and the tabbing for the recently installed chain locker - forward and aft tabbing.
As can be seen in these pictures, I did come back and apply additional fairing compound to low spots and other voids within the laminate. The picture clearly shows the chalky appearance of the sanded surfaces, as well as the newly applied fairing compound. I also repainted the inside of the chain locker where I had sanded the tabbing (forward side of the chain locker).
Total Time Today: 5.25 hrs
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