Cracked Hull

[otterby]

I bought a 20' Cobalt earlier this spring an have had the boat out many times. The boat is great except it leaks pretty good. I finally had some time to investigate. Under the outdrive on the exterior was a bunch of silicone caulk, I assumed this was the problem area so I filled the hull with a few inches of water and sure enough it started dripping around the caulk. I peeled off the caulk and found a pretty good crack that obviously goes through the fiberglass. You can see this in the attached picture. My idea was to grind the gelcoat off along the crack and fill with a marine epoxy. Is this a good idea or does someone have a better way to repair this crack. It looks pretty much impossibe to do much from the inside without removing the engine. Thanks for the help.

 

[m_87]

Re: Cracked Hull

i am not very experenced with this but i would remove the engine and take everthing out down to the hull fiberglass the inside then go to the outside sand it down really good and re fiberglass the outside too also check the rest of the boat for rotten wood if you have had water getting in allot there might be a new deck in need..

you might get away with just sanding down the outside and re fiberglassing it but make sure you prep it right.. i wouldnt epoxey it again think about this if you dont to it right its possible that if you take it out it takes on lots of water you might sink the boat..

 

[petermarcus]

Re: Cracked Hull

You might want to try to figure out what caused the crack. If your transom is rotten, then the hull flexed under acceleration (because there was no support) and made the crack. You could seal the crack, but the underlying problem is still there and eventually your transom would fall apart. If it was cracked from backing into something, again you'd have to worry about water getting into the transom and rotting it out.

You might be able to drill a couple holes into the transom from inside, next to the engine and make sure the wood is okay.

 

[otterby]

Re: Cracked Hull

I've inspected everything pretty close and can't find any other issues. I don't think anything is rotten. I would really like to do this the best way possible without removing the engine.

 

[Borchik]

Re: Cracked Hull

thats not good, thats cracked along the area where it mates at the bottom, thats due to either rotted wood or impact damage thats gotten worse, unfortunately there is not an easy fix to repair it properly.

 

[otterby]

Re: Cracked Hull

When I bought the boat it was set up for wakeboarding. It had a 12 pitch prop and 3 fat sacks. There was a lot of added weight and not near enough pitch on the prop. A 17 pitch is correct and what I have on there now. It's a 1988 Cobalt which to me isn't too old and a well built boat. Was the previous owner trying to move too much weight and putting too much power against the transom?

 

[Woodonglass]

Re: Cracked Hull

Regardless of the cause, you have a problem that has to be fixed. The Water intrusion into the transom will continue to cause damage and weakness to the transom to the point of a catostropic incident. IMHO you should not be using the boat until that problem is fixed. Especially towing.

I'm just sayin...

 

[otterby]

Re: Cracked Hull

Ok, I've decided to cut into her and fix it right. Any suggestions would be helpful. It looks like there is a few different types of fiberglass/resins. Which is the best for my application.

 

[RobbyA]

Re: Cracked Hull

Regardless of the cause, you have a problem that has to be fixed. The Water intrusion into the transom will continue to cause damage and weakness to the transom to the point of a catostropic incident. IMHO you should not be using the boat until that problem is fixed. Especially towing.

I agree....


I would also like to point out that it looks like the transom is smiling at you .

 

[Woodonglass]

Re: Cracked Hull

Your Transom is probably rotted and needs to be totally replaced. You can repair the fiberglass skin at the time you repair the inner wooden core of the transom. There is a strong likelyhood that your stringers are also toast. This means a total rebuild of the superstructure of your boat. If you want to undertake this effort then this thread...

http://forums.iboats.com/showthread.php?t=358277

would be a GREAT place for you to start to get an understanding of what is needed to get the job done. This guy did it with little or no experience and he did an excellent job. You can do it to with the help of all the guys here on the forum

Remember, with time, money and beer you can do anything.

I'm just sayin...

 

[otterby]

Re: Cracked Hull

Thanks for the help. I'm sure I'll be back looking for more real soon.

 

[grsmnky1]

Re: Cracked Hull

Otterby, I see this was a spring purchase and you haven't had the boat that long. You should do a very thourough search on transoms and restorations before you purchase any supplies. It is a lobor of love and not for the faint of heart whatever you figure it would cost triple it and the time you think it will take. However if your powerplant and controls seats etc. are good a inexpensive replacement hull is a viable option. Good luck either way
DC