transom repair options

Scott Danforth

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Heavy motor hanging on rotten transom = bowed transom

Bet there are spider cracks in the gel in the splash well too
 

so

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so got to cut off the splash guard today, still not convinced the transom bow was due to rot/age, see the contour of the joint between the deck and the transom.
20230708_175751.jpg

anyhow, going to do complete replacement. One question, instead of retaining the outer skin and grind away the wood , can I completely remove the transom and retain only 4 inches along the perimeter of the outer skin, this way I only need to grind the 4 inches. I haven't seen any youtubers done it this way so wondering there is a big down side to it.

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Scott Danforth

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It's 100 times harder to repair from the outside

You also have the stringers that are shot as well.

Pull the cap and do it right
 
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so

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so most of these youtubers did it from the outside, except friscoboater, who is also a memeber in this forum, did it from the inside. But one thing they all have in common is that they keep one side of the skin entirely and go thru the dreadful process of chiping/grinding away the plywood. So my question was why not completely cut away the transom and retain only 4 inch perimeter regardless you do from inside or outside, then minimal grinding.

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Scott Danforth

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If you do it from the outside and you leave a 4" border, that is not a full transom replacement. The transom and stringers are the spine and skeleton of the boat. Not doing it correctly will lead to a catastrophic failure.

Most facetubers do things wrong
 
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mike_i

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I used to live in Lakewood and still have a house there, now live in OC. There's a good boat/fibergalss business is Santa Ana you may be able to pick their brain for ideas.

Near Lakewood, 91 fwy and 605 fwy.
 

so

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If you do it from the outside and you leave a 4" border, that is not a full transom replacement. The transom and stringers are the spine and skeleton of the boat. Not doing it correctly will lead to a catastrophic failure.

Most facetubers do things wrong

I was referring to something like this, see how they completely cut off the old transom and kept just a border on the outside and just drop in a new transom, no need to peel, chisel, grind, sand the old wood off. This way you get to practice your tabbing/fiberglassing skills without the nasty grunt work

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briangcc

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I wouldn't do it. You're cutting into the hull of the boat for what purpose? Gonna be a chore and a half getting that lined back up and gelcoat color matched. Not to mention having to wrap your outside fiberglass around the corners and keel of the boat. What exactly do you think you're saving time wise?

Leave the outside alone and replace it from the inside. That way, as you're learning about fiberglass layups, your not so perfectness will be hidden under the splashwell.
 

KJM

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Dont cut the outside FG. You will never get it back as strong as the original. All the force of an outboard will be on those new joints. Getting the wood off from the inside isn't as hard as you think. Hammer and chisel, some grinding or whatever. I would consider using cooza or some other composite instead of wood in the replacement. More expensive but will last a life time. You don't want to do this more then once. As said above, its easier to hide cosmetic mistakes inside rather then outside, and you will make them, trust me!
 

so

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got a good chunk of the old wood off.
question, to reinforce the inner corner between the new transom and the side of the hull, how should I prep the existing fiberglass of the side? just clean it with acetone?

is this the proper procedure? first layer is CSM, then several layers of 1708 with different width so that each outer layer overlaps the one underneath?

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88 Capri (2022 SOTY)

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Wherever you are going to lay new fiberglass the part of the boat not being replaced but has gelcoat on it must be ground down to good fiberglass.
Just wiping down existing gelcoat with acetone is not enough, you will know when you have the gelcoat removed because the fiberglass may have a pinkish color. Then you would wipe it down with acetone prior to using PB or laying new fiberglass.
I used 36 grit flapper wheels to remove it, proper PPE is a must!
Dust mask (at minimum) safety glasses, tyvec suites and gloves will greatly help in preventing the itchiness among other things.
 

tpenfield

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Following along. I lived in Pasadena for a few years shortly after college. I didn't do any boat work out there, but recall it sure got hot in the summer. So, working temperatures may be a consideration when you get to the glassing stage.

I've seen a few transoms done from the outside, but it is good that you are working from the inside.

It does not look like there is much of a stringer system in that boat, so you could add some bracing to the new transom.
 

Scott Danforth

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got a good chunk of the old wood off.
question, to reinforce the inner corner between the new transom and the side of the hull, how should I prep the existing fiberglass of the side? just clean it with acetone?
Many many many hours of grinding down to good glass with 24 or 36 grit. Don't forget the full face respirator, tyvek suits, gloves, etc
 

so

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finally got some spots down to the FB on the transom.
regarding the side, looks like it's just FB or is it gelcoat?(did some grinding , see yellow circle.) If it's just FB, is it okay to just clean with acetone ?

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KJM

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I think the white is still gelcoat, the dark is FG, That being said, don't grind too deep. You might not get all the gel coat, but get a little more. The new resin will probably still stick to the old exposed gelcoat just as well as the FG anyway. This is just my opinion, others who know better might disagree. Some fun, isn't it!
 

Scott Danforth

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You have to grind thru the gel to fiberglass
 

Drivewayboater2

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Scott is correct! You gotta get down through all the gel coat to get a good bond with the new stuff. It’s a long messy process but it must be done. Go at least 6 inches past where you think you’ll be laying new fiberglass. That way you’ll sure to leave yourself plenty of working area.
 

Drivewayboater2

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Is that still wood at the very bottom? ( from post 34 top pic) You may need to chisel that out in order to get a solid sheet of plywood up against the entire transom.
I used pink foam insulation to may my transom template once you get to that stage.
 

KJM

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Get yourself lots of clamps and watch lots of videos and read the stickies on the subject. There's lots of info here and on YT.
 
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