1967 MirroCraft Sportsman Runabout Rebuild

[Creekerman]

Picked up a boat and trailer in early 2014 for about the price of scrap metal. The trailer was solid with nearly new tires and wheels. The boat had seen major modifications over the years. The strength of the side panels of the hull had been compromised due to removing the original bench seats. A former owner had welded various braces along the length to support the sides. The boat came with a non-functioning 10 hp Eska motor which I peddled at metal recycling business for $30.00.

Sent an e-mail to MirroCraft in Manitowoc WI to determine the year and model of the boat. With the serial number taken from the original transom capacity plate, MirroCraft determined the boat was a 1967 model. They were uncertain of the exact model, but the transom cap. (45 hp), the total cargo-persons-gear cap (960 lbs), and the 63 inch beam would suggest that the model was a Sportsman Runabout. They had sent me a pdf copy of the 1967 MirroCraft brochure (see attached pdf file).

The rebuild began about the 1st of March 2014. I decided to target the interior of the boat and planned to begin the outside during the autumn of 2014. I began the project by stripping almost everything of the existing interior out of the boat. A custom fitted live well had been installed by a previous owner in the front seat position of the boat. I kept the live well shell in place and some of the aluminum framing in the bow. Everything else, including the transom board at the stern was removed...seats, seat posts, some make-shift bracing, old battery frames and all the electrical wiring and switches.

 

[Creekerman]

Can someone coach me on how to rotate the pics to their proper position? I've tried to rotate them upright several different ways....they continue to show up sideways on the posting.

 

[Creekerman]

The first part of the interior rebuild involved filling/patching holes in the hull. for many of the small holes, I used the best-fit sized aluminum pop-rivets and coated them with 3M 5200 sealer. Some other holes were better suited for patching with JB Weld. Some of the holes required filling and patching with aluminum wire-welding which I had done at a local welding shop. When I removed the transom board, I discovered that a previous owner had already replaced it with treated wood. There was some pitting, but it was not extensive yet. Grinding, polishing, and hand-sanding effectively addressed the pitting problem.

The next phase involved preventative leak-proofing of the rivets and seams. I used a simple Chicago side grinder with a wire brush attachment to clean up the area around the rivets. I discovered that this needed a light touch as the wire brush can easily take too much surface metal away instantaneously. I also used medium sanding sponges to polish the area around the rivets/seams.

I chose to use the "Goop Coat-It" epoxy sealer product for waterproofing. I used the greater portion of one quart to completely coat all the rivets/seams. I let the sealer cure for almost 3 full days before the next phase.

To prep for the primer coat, I used medium and fine grained sanding wet sponges. Completely hand-sanded the interior surfaces that were to be painted. I then washed the interior with light solution of water and white vinegar. The information I received from many posts and some local consultation indicated that Aluminum begins to oxidize already within 10-30 minutes after sanding. After sanding and a quick light vinegar wash, I quickly rubbed down all those surfaces with acetone. I had the spray gun and all other preps for the primer coat readied and started applying the primer immediately after the acetone wash.

For the interior primer I chose to use "SEM Metalock" high build primer. Metalock is a 2-part epoxy primer. It was quite expensive, at about $140 for a quart, but one quart was more than enough to cover the interior portion of the boat. I had read several posts/sites that indicated that usually 3 steps were indicated for painting bare aluminum...etching primer, sealer, and builder coats before any cover coats. All the primer coats needed to be products that were chemically compatible with each other. The Metalock product claims to provide all three steps in a single application = primer, surface, and sealer. The Metalock directions state that a cover coat can be applied within one hour of the application of the Metalock primer without sanding between coats. That is the option I chose. I applied the first cover coat one hour after the Metalock coat was completed. I used a low-cost Kobalt gravity-feed spray gun purchased at Lowes and set at 24 psi nozzle pressure to apply both the primer and cover coats.

The cover coat I chose was Rust Oleum "Topside" semi-gloss white. I applied two coats over the Metalock. The Topside paint indicated that a 24 hour period of drying was needed between coats. I did a light-fine sanding between coats.