Motor and Motor Bracket, Part 7, Painting Components

Pitthane two-part polyurethane paint by Pittsburgh Paints
Having fabricated the various pieces of aluminum and having constructed, epoxy-coated, and sanded the various pieces of plywood, it was now time for me to paint all of these pieces with two-part polyurethane. This two-part paint would provide a durable finish that would protect the aluminum from corrosion and protect the epoxy-coated plywood from ultraviolet degradation. How I carried out this paint job on these pieces for Oystercatcher, my Ericson 25, is the subject of this posting.
I've discussed the virtues of Pitthane in numerous postings, specifically those concerning the lazarette and the V-berth lockers. Therefore, I will not discuss this paint in any great detail here. In preparation for applying the first coat of Pitthane to the aluminum, I sprayed a scrap piece of aluminum with Zinc Chromate primer. I've also discussed this primer elsewhere. This is some seriously toxic stuff that is, I believe, banned in some states of the United States. Here in Charleston, South Carolina you can buy it off the shelf at the local hardware store. This stuff is apparently what they used to use to prime aluminum aircraft during WWII.
The Zinc Chromate worked well, as it had in the past, and the Pitthane adhered well to it. Needless to say, I wore long sleeves, gloves, and a respirator for this work.
In preparation for the priming of the aluminum pieces, I sanded them with 60 grit paper.
This put nice swirls in the surface of the aluminum which would give the Zinc Chromate some extra "tooth," as they say.
Above and below we see the aluminum backing plate for the cockpit side of the transom.
In the next two pictures we see the plate for the exterior of the transom.

Next we see the motor mount pad - a piece of epoxy-coated mahogany sandwiched between two aluminum plates.
Finally, we see the plywood backing plate for the cockpit side of the transom and the transom cutout.
Prior to spraying the aluminum I wiped the pieces down with acetone to remove sanding dust and other impurities.
Yes, the aluminum needed it.
Now it was time to shake, rattle, and roll.

Before I sprayed the motor mount pad, I applied blue masking tape to the mahogany. I also filled the large holes with wads of tape to prevent the primer (and later the paint) from affecting this space.

Below we see the motor mount pad after I have primed both sides and after I have removed the blue masking tape from the mahogany.
I primed both sides of the aluminum plate that would be on the cockpit side of the transom. I did not prime both sides of the plate that would be on the exterior of the transom. This one I would join to the exterior of the transom with adhesive. Therefore, I did not want to have paint on the side that would receive the adhesive.
With everything now primed and ready to go, I broke out the Pitthane.
On went the first coat.

The next day, after I had lightly sanded the surface of the Pitthane with 320 grit paper to remove imperfections and provide some tooth for the next coat, I broke out the Pitthane again. I did this work in the summertime, and I never left out the Pitthane overnight, especially since the hardener (in the small can) is sensitive to warm temperatures. At night, I would store the Pitthane in the air conditioned climate indoors. The next day I would set it out for an hour or two before I used it. This would allow it to come up close to the outdoor temperature, which was usually over 90 degrees Fahrenheit.
The second coat.

The next day, out came the Pitthane again.
I applied a third coat to the first side of the cockpit plate . . .
and a third coat to the exterior side of the transom plate.
I did not, however, apply a third coat to the first side of the plywood backing plate. Instead, I flipped it over and applied the first coat on the other side.
I did the same thing to the motor mount pad.
The following day the Pitthane came out again. The plywood backing plate and the motor mount pad got a second coat.
The opposite side of the cockpit plate got a first coat and then the next day a second one.
Like so many other sub-projects on this boat, this seemingly simple task was one that took a lot of time and effort. I have included all these pictures, as I do in so many other postings, to remind myself and to point out to others how tedious this all could be. Now that it is all over I can say that it was worth it, but at the time it certainly didn't seem so.

This ends this posting on my painting of these pieces for Oystercatcher, my Ericson 25.

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