Completely clueless

So since I cut out the exterior I need to cut some of the bottom of hull? I'm trying to understand but I still dont know a lot of boating lingo

 

What these gentlemen are saying, is you should have left 2-3 inches of the transom glass adjacent to the bottom, intact. But all is not lost, you will have to connect the new transom glass to the bottom of the boat on the inside, rather than the outside of the transom, as you should have done. But that will take a little ingenuity, not too much, really.

 

But the glass was broken at the corner of the transom and hull. What problems will I create if I just remake the exterior corner

 

I hear what you are saying, the difficulty here is being unable to assess the situation accurately, without seeing it. Was the glass broken, or just gel coat ? The problems with glassing round the corner on to the bottom, are not insurmountable, but it would have been preferable not to do that. But no matter, you can do that, and add some extra insurance by extra glass on the inside of the boat, onto the transom ply, and on to the bottom. All is not lost, the situation is not yet "hopeless but not serious".

 

The glass was broken. Was about quarter inch thick. And as I've never glassed I'm not sure the amount of layers to put there or the thickness each layer adds. I'm very analytical

 

As I say, it is difficult to assess without being there in Montana. I believe the smallest population state in the USA ?
As has been mentioned, you have to feather any joins with glass, and transition gradually from one part to another. The worst possible thing would be an attempt to "butt join". But it isn't much use feathering glass that is already half-busted, you need to start with something sound to attach to. Can you turn this boat over, at some stages it will be much easier to work on, if you can.

 

It would be possible to flip over but that's a ton of rivits I would need to drill out to remove the cap. Not really something I planned on delving into. Maybe after I'm done repairing the floating issue and pay off the credit cards from this project I can work on making it look prettier.

 

All is not lost nor hopeless. Even th external crack would have been easier to repair from the inside. Qbones 99.999% of fiber glass repairs are easier from the inside. The exception being when the interior furnishings are obnoxious to gain access. Since you have already removed interior, try to think how to work from inside.

New term "scarf joint" the materials are joined with an angled cut. Vs "butt joint" joined at nearly 90° angle

Plywood is usually 8-1. Fiberglass 12-1. So a 1 inch thick plywood would have an 8 inch wide joint. 1/2 inch thick fiberglass a 6 inch wide overlap.

This ensures that the materials will flex without breaking a the joint.

I have a new device and have not learned its drawing program. So here is a photo of how your transom cross section should look. Good luck

 

It will be hard work, working overhead, on the bottom/transom repair. Not a job to relish. Are you going to keep that old ply in the transom ? If you remove the aluminium strips on the transom, you might be able to slot in a new one.

 

That is a pretty good picture from blueknarr, one wonders whether this thing is salvageable, it the glass under the boat is busted, near the transom, it does not look too bad in the pics posted by the OP, but things always look better in pictures !

 

I believe I would have to cut the entire back of boat off. As stated before the exterior fiberglass seems to be attached to transom wood. And to remove the cap is lots of work and rivets.

 

It would look worse but after I cut the back off I smoothed all the sharp points from the broken fiberglass.

 

Easy to drill out the rivets, and pop the transom cap off.

 

Popping the cap off is extra work that I'm not comfortable with trying to repair. Again not trying to make more work until I've fixed what absolutely needs to be done.

 

I could not countenance leaving an old piece of ply in there, it must be in a distressed state. The transom is pretty well the main game, that needs attending to.