Any Transom experts here. I have a Transom Rebuilding Question.

[1985 Century Mustang]

I'm almost done pulling out all the hardware I'm redoing the transom. Question concerning the transom itself. It looks like there's a sub transom where the transom plate goes. Are there two separate transoms. It seems like where the transom mount goes it bumps out. Shown in the photo below.

 

[1985 Century Mustang]

It looks like there can be two transoms, or an extra bumped out transom where the actual transom mount attaches, if that makes sense. I'm a rookie at this. I'm just wondering how it's designed.

 

[tpenfield]

What's it look like from the outside?

Either the transom is notched, or the area around the outdrive's transom assembly is thicker than the rest of the transom.

It is a bit hard to tell from the picture . . .

 

[1985 Century Mustang]

What's it look like from the outside?

Either the transom is notched, or the area around the outdrive's transom assembly is thicker than the rest of the transom.

It is a bit hard to tell from the picture . . .

The outside transom area is indented inwards in the center, I'll take a picture tomorrow.

 

[1985 Century Mustang]

What's it look like from the outside?

Either the transom is notched, or the area around the outdrive's transom assembly is thicker than the rest of the transom.

It is a bit hard to tell from the picture . . .

 

[Chris51280]

it looks like somebody else worked on this before. boat is 40 years old and probably had work done before. I assume you are not the first owner. The white outer skin seems to be the original and the dark wood was a patch job. Hard to tell from the front view. You can clearly see the silicone patch on the outside. you can look in my build on a century boat that has a similar transom design

 

[1985 Century Mustang]

it looks like somebody else worked on this before. boat is 40 years old and probably had work done before. I assume you are not the first owner. The white outer skin seems to be the original and the dark wood was a patch job. Hard to tell from the front view. You can clearly see the silicone patch on the outside. you can look in my build on a century boat that has a similar transom design

No, I had cut out that part to assess where the water was coming in. That dark wood was there already when I removed all the rotted wood. I was just looking to do a patch job myself but realized I need to do it right the first time. That's why I'm confused that it may have two transoms.

 

[1985 Century Mustang]

And I'm wondering if I can just rebuild that center part of the transom where it's decayed. So far It seems the wood to the left and right are ok. I'll know when I open it up more.

 

[Chris51280]

 

[Chris51280]

I don't think you have two. You can just fix the center piece but the decay is also in the stringers. Most notably was the bulkhead between the motor bilge and the tank compartment.

 

[1985 Century Mustang]

View attachment 396903View attachment 396904

Thanks so much, I'll assess everything you have mentioned. I really appreciate the quick response.

 

[Scott06]

Thanks so much, I'll assess everything you have mentioned. I really appreciate the quick response.

drill holes in stringers as well. Usually if the transom is gone so are the stringers. May only be the back part near the transom may be all of them. Would also look at the motor mount stringer and in ski locker if there is one.

 

[1985 Century Mustang]

drill holes in stringers as well. Usually if the transom is gone so are the stringers. May only be the back part near the transom may be all of them. Would also look at the motor mount stringer and in ski locker if there is one.

Thanks, I'll check. FWIW The front motor mount stringer seems to be pretty solid.

 

[Scott06]

Thanks, I'll check. FWIW The front motor mount stringer seems to be pretty solid.

if the lag screws didnt jank out when you pulled the motor that is a good sign

 

[1985 Century Mustang]

if the lag screws didnt jank out when you pulled the motor that is a good sign

Are the lag screws the front lag screws or the rear ones? I don't understand what you meant by lag screws. Did you mean the motor mount bolts?

 

[1985 Century Mustang]

I removed the gimbal housing today. I noticed there seems to be a thin layer of fiberglass on the inside of the transom right after the gelcoat. Does this have to be removed also along with the rotted transom wood. If so would they sell this if it's an actual piece of fiberglass gasket type thing.

 

[1985 Century Mustang]

Bumping this. Please read, need an answer.
https://forums.iboats.com/threads/a...ansom-rebuilding-question.772267/post-5918537

 

[JASinIL2006]

Looks like the fiberglass hull (outermost layer, 1/4”-3/8” thick) has delaminated from the plywood transom core. Is not the inner layer fiberglassed plywood?

 

[1985 Century Mustang]

Looks like the fiberglass hull (outermost layer, 1/4”-3/8” thick) has delaminated from the plywood transom core. Is not the inner layer fiberglassed plywood?

No it's definitely a fiberglass gasket of some type.

 

[todhunter]

Never heard of a fiberglass gasket. It's probably just the inner fiberglass skin, or what's left of it. You're either going to have to remove the inner skin or the outer skin to get all the rotten wood out. I can almost guarantee you aren't going to be able to find a pre-fabricated fiberglass skin, and if you did, I wouldn't use it, as it would be incredibly difficult to get it to have as good a bond as you laying your own glass.

Lag bolts look like big wood screws with a bolt head, and are what hold the metal motor mounts to the boat hull. Usually they go into raw wood and are not sealed, so it's a potential entry point for water to start rotting the wooden mount pads, which if connected to the stringer/bulkhead network and the transom, can cause those to rot too.

You said the motor mount stringer "seemed pretty solid". How did you check? If you didn't drill a hole and look at the wood shavings, you're not really checking.