Transom Rotted

dolfan1710

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Jun 27, 2018
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I dropped my boat off at my mechanic for a starting issue and have been informed my boat is taking on water because the transom is rotted. It’s an arm and a leg to fix so I’m pretty much out of the game. The boat is an 1988 stingray SVB 176 how common is this? It was garaged winters the majority of its days all but the last 3 or 4 years. I see older ones on the water all the time, just curious.
 

HT32BSX115

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Dec 8, 2005
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I dropped my boat off at my mechanic for a starting issue and have been informed my boat is taking on water because the transom is rotted. It’s an arm and a leg to fix so I’m pretty much out of the game. The boat is an 1988 stingray SVB 176 how common is this? It was garaged winters the majority of its days all but the last 3 or 4 years. I see older ones on the water all the time, just curious.

Howdy,

It's fairly common in older boats. It doesn't take much water intrusion into the transom via either the transom mount or via other holes in the transom that leaked. A very common point of entry is the transom (bilge) drain itself. Water gets into the wood under the fiberglass and the rot starts.

The only reliable fix is to remove the fiber glass on the inside surface of the transom and remove all the old wood. Then replace and glass-in the new transom.

In many cases you have to remove the deck and floor area around the "engine-room" to get to all the rotton wood and have a large enough area for the new structure to tie to

For a 1988 boat, it's usually never worth it unless you want do other fiberglass work like replace the floor and stringers etc.

You have to enjoy working with fiberglass too.

If you have to pay someone to do it, you're better off parting the boat out and finding another one.

Sorry about that.

Regards,

Rick
 

dolfan1710

Seaman
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Jun 27, 2018
Messages
73
Thanks! What’s a fair price for a parts boat like this? Everything works but it eventually needs its second cam seals job. Last season I found All the antifreeze leaked out from the weep hole. I refilled it and ran it all season and this past winter not one drop leaked out. Still think it is probably coming though.
 

HT32BSX115

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Your best bet might be to find a nice boat that has a cracked block (from a previous poor job of winterization) if you want to swap all your engine/drive etc over.

Otherwise, part out your boat, sell engine drive and other "stuff" including the trailer and find yourself a nice (newer) similarly sized & powered boat.
 

tpenfield

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Yes, a 35 year old boat is bound to have structural issues, even if kept inside.

You could fix it yourself, but expect to find more issues than just the transom. I don't think selling it as a parts boat will get you much. But maybe sell the parts of the boat would be more.

You could also restore the boat yourself. Lots of folks have been down the road you are on and fixed their boat to get many more years of use out of them.
 

tank1949

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Apr 4, 2013
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Thanks! What’s a fair price for a parts boat like this? Everything works but it eventually needs its second cam seals job. Last season I found All the antifreeze leaked out from the weep hole. I refilled it and ran it all season and this past winter not one drop leaked out. Still think it is probably coming though.

It is a "job" to replace and I/O transom. I just completed 6 months of removing and re-glassing (but I am old and can't work all day in the heat). U'd better have air tools, place to store motor, etc., and patience. An incompetent marine surveyor missed identifying my rotten transom. A local glass shop provided a 3,400$ estimate. But mine has twin I/Os. That estimate DIDN'T include metal removal.
 

Scott Danforth

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Keep in mind, your boat had a 15 year design life and its 32 years old

Most fiberglass boats from the 80s and 90s suffer rot, many didnt make it past 15 years. You managed to make it 32 years

If you love the boat, you can rebuild it. It will take about $2000-3000 worth of materials to restore the hull (stringers, bulkheads, transom and floor) if you do the job yourself. It will take about 400 hours of your time. We will be here when you have questions.

If you plan on parting it, you can sell it off piecemeal and make the most, however that may take years
 

Bondo

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Last season I found All the antifreeze leaked out from the weep hole. I refilled it and ran it all season and this past winter not one drop leaked out.

Ayuh,...... Sounds like it's got a 470 motor,....... Strike 2,......
 

tank1949

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I have removed or overhauled 6 transom assemblies in my life time. Most were Alphas. My last two were Bravos. Every transom seal was flattened and appeared to have lost its pressure to provide positive pressure where needed. Salt water will find any opening and eventually rot wood. The best materials to use in rebuild is total synthetic (not plywood), but it is expensive. Most transoms require at least 2 4x8 sheets at about $300 each. Marine ply is < $100 each. I used epoxy on ply and coated all wood, even the 1/2" transom stud holes. As an extra precaution, I am caulking gimbal housing to transom. It may not be a common practice and looks like crap, but provides me some degree of more sleep at night. My drain hole area is epoxy/silica mix with fg matt/cloth and covered by 1808. Saltwater will never leach into the ply (I hope) at the drain. But at 70 years of age, I suspect I will be dead before any wood rot screws up my fishing. I don't plan on selling the boat. If your motors are saltwater cooled, I doubt that you will get anything for them. I feel your pain. I have been where you are more than once. There are plenty of folks like me on this forum who can help you out. This aint rocket science! If it is hot where you live you and you will be rebuilding, invest in a large fan and awning. Air tools are great, especially an air chisel, but not necessary. You will need an engine hoist and motor stand. That is an extra expense. Good luck.
 

HT32BSX115

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The best materials to use in rebuild is total synthetic (not plywood), but it is expensive. Most transoms require at least 2 4x8 sheets at about $300 each.
What sort of stuff is that? Pre-made fiberglass matte sheets or other glass/epoxy or carbon fiber like material?
 

porscheguy

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What sort of stuff is that? Pre-made fiberglass matte sheets or other glass/epoxy or carbon fiber like material?
He’s referring to a product called Coosa or coosa board. I can’t remember if it’s plastic or pvc reinforced with fiberglass. Many new boats are built with it as it doesn’t rot.
 

Scott Danforth

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He’s referring to a product called Coosa or coosa board. I can’t remember if it’s plastic or pvc reinforced with fiberglass. Many new boats are built with it as it doesn’t rot.

actually, most high end boats avoid it and go with engineered stringer tubs and transoms (foam filled honeycomb structure)
 

dolfan1710

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Jun 27, 2018
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Thanks guys! So I picked up the boat today and found that yes the swim platform has some flex in it. I tried tightening the nuts but the bolts just spin. It seems to be mounted behind the gas tank so I can't see what's going on with the bolts unless I remove it. Is anyone familiar with how these swim platforms are mounted in 1988 Stingray's? Is the spinning bolts a tell take sign that the transom is rotted? The mechanic was much more eager to show me the swim platform than the outdrive which may have a tiny bit of flex with a high effort attempt to move it. I'm skeptical because I dropped the boat off for them to check a no start issue. I've been out twice and after running for about an hour the boat wouldn't crank, no clicking or nothing. The last time I went out (last Saturday) I ran for about an hour, removed the engine cover to play with the wires that connect to the starter and didn't notice any water building up in the engine compartment. Is this where it would build up? I even know for a fact I ran the bilge pump to see if it worked and not a single drop came out of the side of the boat. These guys are telling me 4 or 5 gallons is pouring out whenever they took it out of the water. I've been out twice for about 2 hours and never saw an unordinary amount of water. Can we take on water from the swim platform?.
 

nola mike

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Swim platform not the most common point of entry of water into the boat, though if the bolts are that loose and below the waterline it's possible, and if below the waterline and that loose you probably do have transom rot. Your platform might use through bolts or screws. Until it gets real bad around the transom plate you probably won't have a leak. Next step should be to drill some holes in your transom and take some clue samples. Head over to the restoration forum for advice on how to proceed.. there should be zero flex in the outdrive and platform
 

tpenfield

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I'd want to see the leak for myself rather than take someone else's word for it . . .
 

scoflaw

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The bolts are loose now because the wood they pass through is now mush, my guess.
 

dolfan1710

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Jun 27, 2018
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Thanks guys! I’ve decided I want to see this thing leak for myself. I’ve been out twice, for at least 2 hours, and barely any water has come out when I’ve removed the plug. Mechanic has it out twice and it emptying 4or 5 gallons. I believe the transom is starting to rot, specifically at the swim platform, but I’m skeptical that the boat is taking on water. My question is if I hit a “no crank” condition is there something I can do to safely start the boat assuming my battery and starting solenoid are good? Can I run a positive jumper from the bolt on the starter that does not have the positive battery cable and the positive battery terminal to start it? The only thing I’m afraid of is seeing that I am taking on water and not being able to start the boat.
 
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