First boat repair on a 1962 Mirro 14 ft tri glass hull with wet foam.

Mike Caruso 6250 · Aug 13, 2017

Hi Folk's
So just retired and bought an old boat on a tilt trailer to just drive around in closed water lakes IL and WI. Well it is my new learning curve Vertical. Boat seemed heavy when removed from the trailer which I rebuilt, LED lights, Timken wheel bearings w/BB, and painted in 4 weeks.
So time to start on the hull. The first thing I found was the transom was rotten. I never saw it when buying because I was so happy to get my own boat and it was only $360.00 for boat and trailer.
It begins I have removed all the rotten wood doing the least damage to the fiberglass as I possible.
Found the hull dripping water after 4 weeks so I put it under the knife. Small hand grinder with Diamond segmented blade and shop vac pulling in the dust. So just about done with the wet foam removal, rotten wet wood floor and transom.
Question is I plan on using Marine Ply in the transom again? Plus I am adding supports from transom to the floor and both sides of the hull. Is two part foam the only thing to use or ???.
Thank you all its small but all mine !!!!! Mike

PAR · Aug 14, 2017

Welcome to the forum.

That looks like an old chopper gun build, so it's naturally heavy, plus the soaked foam. With the foam removed, you've save quite a bit. Don't over think the additional reinforcement thing. These puppies were over built to begin with and adding weight, is a performance killer in in small craft.

Before cutting out the skin on that transom, it would have been wise to leave a much larger flange around the perimeter, so you wouldn't have to "retab" the core in place. Now, you'll have to retab the inside at least with additional fabric. You don't need to replace the foam and with it being missing it won't trap moisture against the wooden structural elements, like it did last time. Pour in foam isn't as good at this as some of the sheet foam you can get at the big box store. It's costly, but easily glued into blocks that can be fitted into the compartments, assuming you want to go this route again..

Mike Caruso 6250 · Aug 14, 2017

PAR said: ↑

Welcome to the forum.

That looks like an old chopper gun build, so it's naturally heavy, plus the soaked foam. With the foam removed, you've save quite a bit. Don't over think the additional reinforcement thing. These puppies were over built to begin with and adding weight, is a performance killer in in small craft.

Before cutting out the skin on that transom, it would have been wise to leave a much larger flange around the perimeter, so you wouldn't have to "retab" the core in place. Now, you'll have to retab the inside at least with additional fabric. You don't need to replace the foam and with it being missing it won't trap moisture against the wooden structural elements, like it did last time. Pour in foam isn't as good at this as some of the sheet foam you can get at the big box store. It's costly, but easily glued into blocks that can be fitted into the compartments, assuming you want to go this route again..
Click to expand...

Thank you for your knowledge and tips. I can see now a larger flange at the transom would have been much smarter for reassembly. The boat is laid up cloth it looks like chopper gun at first but lots of hand work went into this hull back in 1962 and the only year the company tried fiberglass. I need to flip it over and show you what I want to do to the hull to get it up out of the water. I had bought a small old Mercury outboard called a KF7 Lightening 10 hp makes about 14 hp. I realize now I need more power as I am looking for around 30 mph you know just enough to make my eyes water Ha.
Mike
I have used two part foam to replace the old foam under the three seats. Very easy to use closed cells so it will not hold water or fuel. Just over fill and use a hack saw blade to cut the extra off. I was thinking of a transom support like pictured and then also connect to the floor. Adding a back splash box where the motor mounts might be a good idea. More pictures