Need Advice on Transom Repair on 29' boat

rybad

Petty Officer 1st Class
Joined
May 20, 2004
Messages
215
I have an '89 Four Winns 285 Vista, twin 5.7 Cobras. Last season, I noticed some dirty water marks in he bildge near the outside port stringer (causing streaking under the engine).. I just starting working on her this Spring, and I crawled in to check things out.

I noticed some "spidering" on the transom (inside). I peeled away the loose pieces and reveiled the dark, soft wood core.

I tapped around, and it "seems" to be rotting from around the drive mount. I suspect the transom seal is shot, and leaking water in and rotting the transom core.

I know I need to gut this out and repair it. However, what is the easist, best way to do this. I have read about the Seacast product, and a lot of info on repairing transoms, but most of it revolves around smaller boats with outboard engines (like the Seacast site).. I cannot get to my transom like those smaller boats. I have good size integrated swim platform, and there is no way to get to the "top" of the transom to gut and fill it in.

I was thinking of probing around, and drilling some small holes to find where the rot stops, then cut out the rotted area to about 2-3 inches into the good core, and replacing it with treated wood and epoxy. I dont know if there are any whitepapers that detail step by step or anything..

So, I need some advice on how best to do this, as I suspect I will have to remove the engine, outdrive, stearing linkage etc... just to get to the rotted area, so I want to make sure I do it so I dont have another problem 5 years from now.

Also, the back outside of the transom seems really solid, so I'm also wondering if it would be OK to use my boat this summer, and do this repair in the fall (October.. In Michigan).

Thanks for any advice.
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: Need Advice on Transom Repair on 29' boat

However you do it all the bad wood needs to come out. Rot is a fungus and will continue to spread until killed or removed. Do a search on ani freeze. Yes anti freeze! It kills fungus.
 

WizeOne

Commander
Joined
Mar 23, 2008
Messages
2,097
Re: Need Advice on Transom Repair on 29' boat

The signs are definitely ominous. Your boat falls into the 'Big Boat' catagory which in my estimation removes it from the typical DYI catagory. One would need more space and more equipment to remove motors etc, but it really is only a matter of scale. The principles remain the same.

My only fear, for trying to run it for the coming season, would be the potential for alignment problems and coupler/ujoint problems. I think, at the least, if you pulled the drives and checked the alignment that that might give you a firm direction to your dilemma.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: Need Advice on Transom Repair on 29' boat

i think we need pics....but.....

a transom is a transom is a transom.....(except curved ones) :eek:

how much clearance is there between the top cap and the top of the transom.......i agree....a 28 foot would be too much trouble to pull the cap....

uasually on i/o's there is a few inches between the cap and the top of the transom.....this will give you room to work....but ittl be a pita.

as for using the craft this year....i would take several core samples to determine the extent of the rot......also bear in mind...the transom is attached to the stringers......

re-doing the transom on a 28 is one thing......refitting the vessel with stringers and a transom is a whole different ballgame.
 

seven up

Petty Officer 1st Class
Joined
Jun 4, 2006
Messages
275
Re: Need Advice on Transom Repair on 29' boat

Well rybad after rereading your post I am thinking not this year. Not yet anyway. Save the money for commissioning, fees, fuel and put it towards removing the motors, drives and everything else in the way.

Tell us more. Is the boat at your place ? On a Trailer ?

If your at a marina it is sometimes difficult to bring in outside people so you should find that out ahead of time.

Your plan sounds good except I wouldn't run her as is. That big transom reminds me of a giant gasket(rotting) between twin 5.7's and a whole lot of money and water.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Need Advice on Transom Repair on 29' boat

i have replaced many transoms, in my life, but when i found my 23' Chris Craft I/O Deckboat had a problem. i let the pros do it.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: Need Advice on Transom Repair on 29' boat

i have replaced many transoms, in my life, but when i found my 23' Chris Craft I/O Deckboat had a problem. i let the pros do it.


WHAT...?????? you...?????

i gotta get glasses.....i thought you said you let the pros do it....:eek:

is it really that tough?...or didnt you want to climb in there and be a contorsionist?
 

rybad

Petty Officer 1st Class
Joined
May 20, 2004
Messages
215
Re: Need Advice on Transom Repair on 29' boat

As far as my situation.. I am lucky enough to be able to do this work myself. My family owns a Railroad Construction company, and we have a large motor garage, all the tools, lifts, cranes, hoists, compressors etc... Pulling the engines and outdrives is about a 5 hour job for me.

The boat is on a trailer, and I can pull in right into the garage.

My only dilema is that this type of think is a bit out of my league. Dont get me wrong, I've done minor glass work before and that type of thing. And, Im not afraid of trying something new (I actaully enjoy DIY projects). But, I just want to make sure I do it correctly.

As far as my transom, its an 89 Four Winns Vista, if you look at the tansom from the side profile, it would look like the shape of a "4", with the swip platform inegrated into the top cap. There is no way to really seperate the two that can tell. Howver, there is some room at the top that I can reach in the bildge if I was goingto try the "fill" method. If the experts think that my plan of cutting a piece to match the removed rot from the inside transom would work, I think I can do that fairly easily. My next question would be.. What type of materials do I use? What kind of wood? what kind of epoxy, and fiberglass etc..


As far as using this season, I do pull the OD every year to grease Ujoints and gimbal, and I have an alignment tool that I used to check the alignment. The alignment is good.
 

seven up

Petty Officer 1st Class
Joined
Jun 4, 2006
Messages
275
Re: Need Advice on Transom Repair on 29' boat

With that kind of workspace and equipment you have the option of removing and re-fitting the machinery yourself and having the wood done by an interested woodworker or fabrication shop.

My personal choice for structural plywood in a boat is Lloyds Approved Shelmarine BS 1088. I know other options are out there that are "good enough" but that's not my thing when it comes to structural components.

Your epoxy requires that it has the ability to wet out the fiberglass cloth that is being used such as 14oz. S-glass for example.

The only thing though is the rotted pieces that you want to replace and not the whole transom core. The joints come to mind so I would want clearance from mechanical components to be able to cap these joints with additional structural plywood the same thickness as the transom core. The dimesions of the cap would be dictated by the expanse of the joint.

Maybe the marina should do it.
 

Bondo

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Apr 17, 2002
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71,087
Re: Need Advice on Transom Repair on 29' boat

If the experts think that my plan of cutting a piece to match the removed rot from the inside transom would work, I think I can do that fairly easily. My next question would be.. What type of materials do I use? What kind of wood? what kind of epoxy, and fiberglass etc..

Ayuh,......

That's what I would Do......

P/T Plywood,+ Lot's of Epoxy,+ Glass........

Epoxy is very forgiving,+ Super Strong.....I wouldn't worry about Joint Strenght....
Just make sure you end up with the Required 2" of Thickness......
 
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