Pursuit transom rebuild for Bracket

Hello to all. I am currently working on a project that I think I need some guidance with. I will post as many pictures as I can.

I bought this little boat thinking I would put a motor on it and go fishing lol. Paid very little for the boat so I found a 2005 Honda 225hp 4 stroke to put on it, as it was rated for a 235hp.
But as I was rigging the motor, bolting it to the transom I noticed the bolts started sinking into the fiberglass skin, actually pulling the transom savers into the fiberglass, but not tightening down. The guy I bought it from bought it for the trailer to put under his 19' Robalo CC. He took the boat to the lake to change trailers and never took the plug out . That was about a year before I took possession. Rain water filled the bilge and was just a few inches below the inspection covers in the deck. I know that that isnt what caused the transom to rot, but, it did let water get into the stringers. They arent rotted but very wet.
The stringers are 2 sided boxes that are made from 1/2" ply and glassed to the hull to form a triangular shape. They aren't coated and don't have glass on the underside. There was 1_2 inches of water inside these boxes when I cut into them. I removed about 12 inches of them when I tore out the transom. They have been draining and I think they are going to dry out fine.

I want to glass up the transom to full height and add a bracket for the outboard.....
I want to make sure that it will all stay together and not drop the 600 pound outboard into the pond!
I will post pictures to show where I currently am at in the project.
I am wanting to redo the configuration at the stern as far as battery boxes and the dropped floor.

 

I am not an expert fiberglass repair guy but I am not intimidated by this project, I believe with some guidance I can handle the job. I have been reading and sifting through the thousands of posts on this forum and others , basically doing my homework before I came to just ask a ton of easy questions.
I plan on using US epoxy 635 thin epoxy with their 3:1 medium hardner.
I purchased locally some 1808 (0,90) fiberglass cloth.
My major questions are about the core plywood and the fact that the original core was 3 pieces across the back of the transom, each one was wrapped in cloth and separately bonded to the outer skin. The transom has a straight center and both sides angle to the corners.
I have already cut my plywood the same and have it dry fitted. I plan on integrating the sides for the battery boxes into the knee braces to help support the bracket. The battery boxes intersect the transom at the point where the angles change. (I assume this was to add the needed support for the transom to add strength.) Also adding 2 additional braces that would be more like traditional stringers, probably along the side of the box style stringers that are currently in place. They would be taller than the box stringers and be integrated seating or storage areas as they would be tall and come above the floor.

 

Is it crazy to have the transom pieced as opposed to layering thinner plywood to try to make the turns? Do the boxes add enough bracing and strength? I plan to put the battery boxes online with the breaks of the plywood and then add the second brace (outside of the storage box) about 12-14 inches more towards the center of the boat on both sides. So the overall box would be about 2'x2' with a divider in the middle and battery on one side.

 

Welcome to the forum.

You're off to a much much better start than most.

Every thing is cleaned up well.

The split up transom plywood was never an issue. Rebuild as was or spend hundreds of hours worping in a single piece. Your call.

Your plan of attack is spot on.

Keep up the great craftsmanship and all will be well.

 

As to the glass and resin choice.

You don’t want to use 1808 with epoxy, it will suck up a great deal more epoxy, creating significantly more cost and weight with very little added strength. 1800 or 1700 is what you should use.

On to the resin, you don’t need epoxy for this repair, in the end the results will about the same either way, both polyester and epoxy will hold up for decades of abuse.

The choice is up to you on resin, there is no right or wrong answer.

 

Ondarvr, thanks for the heads up. I was originally going to use Vinylester resin. I have about 30 yds of 1808 now because I was going to ATTEMPT to build a full flotation bracket, but then came across a suitable aluminum single bracket on EBay for 300$.
Would it be feasable to tear the CSM off the back of the 1808? Just thinking that it would suck to waste 200$ of cloth. I also already have about 5.5 gallons of epoxy, 4 gallons of caboodle, milled fibers and some fairing compound mixture.

 

Thank you for responding, I thought I had a good plan but just started second guessing myself and wanted to put this out there for public scrutiny to see if someone found any fatal flaws before I started going back together.

 

Progress has been slow but, finally getting more time to do some work.