1977 Mirrocraft V-hull repairs

[rmfish]

Hello,
I have inherited (after being passed around to other family members) my grandfather's 1977 Mirrocraft V-hull with a 1982 25-hp Evinrude tiller motor. The boat has 3 bench seats and a bow step. The original transom rotted out a few years ago and was replaced with a pressure-treated 2X. I brought the boat into my shop to get the transom replaced. The front seat has curved down in the back for a number of years. I just thought the aluminum had stretched/ bent, but after further inspection, I realized the seat has 3 wooden supports and the back one has rotted. The side panels that protect the foam have also rusted significantly.

So I have removed the transom and there is some corrosion underneath but doesn't seem too bad. And I have torn the front seat apart. The wooden supports look like basic pine boards. I am surprised they have lasted this long. There are also some cracks in the support bracket connected to the boat that will need to be welded.

I want to repair this as best and permanently as possible and was hoping to get some good advice, so here are some questions.

For the transom, I was thinking of replacing it with an aluminum one. Is Tiny Boat Nation the best source? Other suppliers?
What is the best way to clean up the corrosion? wire brush, vinegar, or other acid product (Lowe's has a Klean Strip concrete and metal prep product)?
I want to paint the aluminum, at least primer on the unexposed surfaces, and primer and pain on the exposed surfaces. What is the best paint and primer? Rustoleum has an aluminum latex primer in a can and a self-etching primer in a spray can.

For the seat, the boards are 3/4 X 2 1/4 inch. The only aluminum tubing I see that might work is 3/4 X 1 1/2 inches. Would this work or does it need to be wood? Any good suppliers for the aluminum tubing? Prices are all over the place for the long stuff.
I'm going to check with my local sheet metal fabricator to see what my options are about replacing the sides.

Thanks for your help,
Rob

 

[airshot]

I would not use a latex paint in the metal. If any of the wood will be exposed, you can't beat Mahogany in a boat !! If your going thru all the rebuild trouble, consider coating all the rivets and seams on the interior with gluvit sealer.

 

[boatyard]

I currently own two Mirrocraft boats and have had several older models as well. My current boat is a 1978 Lakefisherman, with a 1986 in the yard as a spare.
My 1974 14ft had wood seat panels, I believe they were either mahogany. Someone had replaced one with a pine plank but I replace it with a white oak plank I had on hand.

To neutralize salt use baking soda and water, then clean it with a grease remover and sand any pits to removed any 'gray' metal that's no longer sound.
Use JB Weld or similar two part filler to repair the pits, then sand and prime with a good Zinc chromate primer.

The transom wood needs to be 1 1/2" plywood. Never pressure treated wood of any type. It contains chemicals that will react with the aluminum when wet.
What I do is to epoxy two layers of high grade exterior cabinet grade 3/4" plywood together, fit it to the hull, drill all the holes large enough to allow some room to move or swell, then I soak the panel with epoxy resin and paint it to match the hull before installing it in the boat.
Keep in mind that what they came with generally lasted 30+ years so anything you do to make it better will only extend the life of the next piece of wood.

I'm a huge fan of coating all seems and rivets with gluvit inside, but you must paint over epoxy since its very poor at resisting UV rays.

I would not sand the hull, the original paint is the best primer you'll ever have, I'd feather out the chips and scratches, fill any deep gouges with JB Weld, then sand and prime the bare spots, then paint the hull with a good automotive or marine grade paint.
I would not use a latex of any sort on metal, regardless of what the can may say.

Most later Mirrocraft boats had metal clad seats made with 3/4" plywood covered in aluminum back filled with urethane foam.
The wood on the ends tends to rot and it takes gutting the seat box to rebuild it properly. On my 16ft 1978, I removed the front bench seat, cut out the foam and dug out the old wood, then cut a new 3/4" seat panel to fit the metal, (I had to weld up a crack in the seat surface and make one new seat top 'brace' or strap. I used layers of 4" thick foam board glued up to make up the lower seat box flotation. (I also doubled the center areas of the seat from below so it gave me more to attach to if I wanted to add a swivel seat or pedestal there later.

I run a 35hp Johnson on one boat and a 55hp Johnson on the other. both motors are 1978 models.

I painted my old boat before I sold it, I used Tractor Supply Majik brand paint with hardener over top of the orignal paint an about 30 primer spots. I mixed two quarts of Cat yellow with one quart of Ford red to get pretty much the original color yellow/orange it was from the factory. The inside got painted with Napa gray speckle trunk paint, it took about a quart to do what needed to be done inside, then didn't paint the aluminum seats, they weren't that bad and didn't want paint rubbing off if it faded in the sun. I coated the floor in Awlgrip industrial walkway paint which covered over the Gluvit on the rivets and seams and gave me a non slip grip surface on the bottom. I did the same to my 1978 16ft as well inside.
Another option inside that works well is truck bed liner coating, but only if you find it in a light color. Black would likely be too hot in the summer. I did my floor in medium dark gray and I coated it up to the first step in the hull on each side and all the way to the bow eye up front. Its never so much as shown a scratch in my current boat over the last 9 years of use.