1974 Crestliner Tri Hull

[kman106]

New to the forum. Hi everyone.

So I bought a 74 Crestliner in "decent" shape this past summer. It floated. Motor ran well. Transom appears to be in decent shape. I really like this boat.

Here's the ordeal. I started noticing some soft spots in the floor. Pulled up carpet and cut some small holes and yes, it's all rotting and waterlogged under there (much worse at the back end of the boat).

I found that there is a plywood floor under the carpet. There are stringers running the length of the boat. These stringers appear to have fiberglass "casings" between them that hold foam.

I am quite handy with building things (I'm a machinist). I'm just trying to figure out what the exact "name" for this floor configuration is, and a step by step guide on how to rebuild. I've read guides and I think I get the basic idea. BUT the fiberglass casings are throwing me for a loop. The wooden stringers are def. rotted, but will I have to cut this fiberglass out to replace them?

Thanks for any help.

 

[jc55]

Re: 1974 Crestliner Tri Hull

Welcome to iboats fellow tri hull'r. There will be lots of good advice coming down the pike for sure. Everything you need will be right here. Woodonglass has a great tutorial.

 

[fishmonster13]

Re: 1974 Crestliner Tri Hull

there are some good tutorials on the forum here, you will need to find out what is in the stringers if its wood , then they will likely need replaced and while you have it apart check your transom, drill some holes in it and see what the shavings look like

 

[kman106]

Re: 1974 Crestliner Tri Hull

there are some good tutorials on the forum here, you will need to find out what is in the stringers if its wood , then they will likely need replaced and while you have it apart check your transom, drill some holes in it and see what the shavings look like

The transom doesn't seem to show signs of flexing. I've read much about transom issues and I've concluded that I'll probably just install aluminum or (if I can scavenge enough) stainless brackets to reenforce the transom. I could drill in and see, but it is what it is, and doesn't seem too bad. Brackets should give me some piece of mind at least...

As for the stringers, I realized that they're wood and have been fiberglassed in. I'm gonna cut the fiberglass out at the base to remove the stringers and install all new wood and re fiberglass it. The wood and foam in this boat is like a wet sponge I cant believe how much extra weight this likely added.

 

[kman106]

Re: 1974 Crestliner Tri Hull

Welcome to iboats fellow tri hull'r. There will be lots of good advice coming down the pike for sure. Everything you need will be right here. Woodonglass has a great tutorial.

Yes people like the Tri hulls. I don't see too many at the lake, but a lot of people look at my boat and compliment it's Trihulledness. It's my first boat so for $1000 for something that gets on the water I wasn't too picky.

 

[jbcurt00]

Re: 1974 Crestliner Tri Hull

The transom doesn't seem to show signs of flexing. I've read much about transom issues and I've concluded that I'll probably just install aluminum or (if I can scavenge enough) stainless brackets to reenforce the transom. I could drill in and see, but it is what it is, and doesn't seem too bad. Brackets should give me some piece of mind at least....

False confidence, IMHO. Your tearing into it to do stringers & deck, why replace the ribs & chest plate if you aren't going to replace the backbone that carries the single most dangerous, heavy & expensive piece of your boat: the outboard? Or at least confirm it's nearly as solid as you think it is.

As for the stringers, I realized that they're wood and have been fiberglassed in. I'm gonna cut the fiberglass out at the base to remove the stringers and install all new wood and re fiberglass it. The wood and foam in this boat is like a wet sponge I cant believe how much extra weight this likely added.

It is more often then not a system wide problem of the wood & foam below decks being waterlogged. The transom included.

You've read thru some threads according to the 1st part of your post I qouted. How many of them are good to go transoms if the stringers & deck are shot? A very, very small percentage. Perhaps you got lucky, but given it's a 40yr old boat, that has some structural wood that needs to be replaced, I wouldn't bet my rebuild, my friends or my family's weekend of fun (or worse) on it..........

 

[kman106]

Re: 1974 Crestliner Tri Hull

Yes you are correct. I have read that in many cases, some rot on the floors etc are a good indicator that there could be some transom rot going on. I do want to do this as well as possible. Like I said, I can lean right down on the motor and I see no movement in the transom. Here are some pictures so maybe you can give me your opinion on how "relatively rotten to other cases of rot" things actually are. The first image is with some of the floor cut out right where the bilge plug is at the back. The second image shows the rear drivers side corner where the rot was the absolute worst after I cut it out (VRO tank was leaking so the oil seemed to have accelerated the rot).

When I ripped the foam in the very center of the boat out, it was actually dry.

Maybe I'm making too much of this, but I feel much more comfortable, skill wise, adding some sort of tabs or brackets to the transom to reinforce it (fiberglass, aluminum, SS?) than actually tearing it out and replacing.

 

[jc55]

Re: 1974 Crestliner Tri Hull

Same situation here. I started building stringers and had a "solid" but wet transom. After a week of setting up heaters to dry out the transom, I faced my fears... It took an hour and a half to remove the transom with the cap out of the way. Then it took about an hour to build the transom(2 layers of 3/4" marine plywood. It took about an hour to pre drill and glass the two pieces together. It took about 2 gallons of resin and 30 minutes to install it. Add another hour or two for potty breaks and such Now I have COMPLETE piece of mind that my boat is about as brand new as it can be with no corners cut.

I had speedo and cable holes, Old Johnson outboard holes, a splash pan drain hole, bilge drain hole, trim and snap holes, tow hook holes, all saturation points. Now I have no holes, dry wood, and can start fresh. You won't regret it.

 

[kman106]

Re: 1974 Crestliner Tri Hull

Same situation here. I started building stringers and had a "solid" but wet transom. After a week of setting up heaters to dry out the transom, I faced my fears... It took an hour and a half to remove the transom with the cap out of the way. Then it took about an hour to build the transom(2 layers of 3/4" marine plywood. It took about an hour to pre drill and glass the two pieces together. It took about 2 gallons of resin and 30 minutes to install it. Add another hour or two for potty breaks and such Now I have COMPLETE piece of mind that my boat is about as brand new as it can be with no corners cut.

I had speedo and cable holes, Old Johnson outboard holes, a splash pan drain hole, bilge drain hole, trim and snap holes, tow hook holes, all saturation points. Now I have no holes, dry wood, and can start fresh. You won't regret it.

So then from my understanding, you essentially cut/pull the transom out from above, by removing the motor and that metal strip/cap right on the top. Then fab a new piece to fit in the "cavity" from above, and seal this in with resin? Do I understand this correctly? There seems to be an infinite number of ways out there to fix a transom...

I poked around the two drain holes for the splashwell and there's definitely bad wood in there.

 

[jc55]

Re: 1974 Crestliner Tri Hull

Yes, but by "cap" I mean, the whole top half of the boat. You can set a circular saw's depth to cut through transom layer #1 (on inside of boat) and pry this layer out. Then you have one layer of plywood left to contend with. Much easier this way.

 

[jbcurt00]

Re: 1974 Crestliner Tri Hull

Not unless you plan on using SeaCast.

It's much more involved then that. The existing wood is glued/laminated onto both fiberglass skins of the transom.

 

[jc55]

Re: 1974 Crestliner Tri Hull

JB, I think he misunderstood "cap" to mean the aluminum trim piece that covers the transom top at the splash well.

 

[jbcurt00]

Re: 1974 Crestliner Tri Hull

I'm sure that's what happened, it's just a big step to have probed & found proof of how bad the transom really might be. So, for now, moving in the right direction is sufficient. The actual what & how's of replacing the transom weren't a priority to explain.

 

[kman106]

Re: 1974 Crestliner Tri Hull

Yes, but by "cap" I mean, the whole top half of the boat. You can set a circular saw's depth to cut through transom layer #1 (on inside of boat) and pry this layer out. Then you have one layer of plywood left to contend with. Much easier this way.

Damn. I had a feeling you meant that! (Entire top of the boat). I've considered removing the motor and cutting that fiberglass layer out from the inside of the boat. So then I'd remove the (probably pretty rotten) transom, fab a new one, glue and fiberglass it in against the outer hulls fiberglass, fiberglass a new layer on top of the inside, and tab the stringers to that new transom using fiberglass? If this can work without pulling the entire top of the boat off, I'd rather stick to this method.

 

[jbcurt00]

Re: 1974 Crestliner Tri Hull

You can just trim the splashwell off, but you need to remove at least that portion of the cap:

This diagram may help you break the cap free from the transom: