Stringer Repair ?

[joepcdr]

Some of you been following and reading my post on the 74 Mercury 650 I'm working on. The boat that came off of is a 73 Glassmaster TriHull. Anyway I've been reading through various forums and post. I'm finding some old info and new info on the topic of stringer replacement. What I'm dealing with was/is a false sense of hope that there wasn't nothing wrong with the stringers do to the fact that the fiberglass encasing them is strong enough to hold my weight without collapsing. I got to doing some poking around what I'm finding is the wood is rotted where they screwed the deck to the stringers. But beyond that the wood seems fine.

My research is telling me I've got my choice of:
using seacast
using some sort of epoxy resin to reharden the wood
or I could rip the stringers totally out and redo them and the fiberglass holding them in from ground up.

None of this I have a whole lot of experience in. Now I did have a nice conversation with the gal that owns the seacast company. She's recommending that if I use seacast I'd have to use it as a total replacement product for the stringers and the deck and not to introduce wood at all. Problem I got is after crunching some numbers its going to be a hell of an expense job to do and apply to a boat that's 40 years old.

I don't know enough about the epoxy option to actually consider that as an option.

Ripping out the stringers totally and replacing them is an option. However, I would have to take some extra steps to prep my shop for that task.

So I know this is a topic that's been beaten around the bush many times. But I thought I'd throw it out there to see what other people have experienced, tried and used that I may not be considering.

 

[ezmobee]

One of the issues you're up against is being a '70's tri-hull, even in MINT condition you've got a boat worth $1995 at best. Yes Sea Cast would have to totally replace the wood and that would be some serious expense. Grinding everything out and fiberglassing it back in is a TON of work but the materials to properly do that size shouldn't be too terrible. I'd either go that route or find a different boat. Finding an aluminum hull to hand your Merc on is an option as well.

 

[jbcurt00]

And there is no majic epoxy product that will do what you asked. No matter what anyone tells you, esp not those that sell a rot getter product. Its merely an expensive bandaid that gives you false confidence that its 'fixed' when it really isnt.

 

[joepcdr]

And there is no majic epoxy product that will do what you asked. No matter what anyone tells you, esp not those that sell a rot getter product. Its merely an expensive bandaid that gives you false confidence that its 'fixed' when it really isnt.

That's kind of what my feelings where on the idea and concept. I kept asking myself, ok you have wood that has rotted to a powder or become strands. Then all your doing it essentially filling it in essentially with a glue. So I'm thinking how can that be even stable.

 

[joepcdr]

One of the issues you're up against is being a '70's tri-hull, even in MINT condition you've got a boat worth $1995 at best. Yes Sea Cast would have to totally replace the wood and that would be some serious expense. Grinding everything out and fiberglassing it back in is a TON of work but the materials to properly do that size shouldn't be too terrible. I'd either go that route or find a different boat. Finding an aluminum hull to hand your Merc on is an option as well.

Let me ask you this and I sort of thought the guy was nuts but the more I think about it it might work. I was reading this forum post to where a guy cut the fiberglass cap off the stringers and dug out all the wood. He cut new stringers and laid them back down, right where the old one was only having to reresin up the fiberglass and put a new cap on. I would assume for this to work there would have to be some way to roughen up the inside of the old fiberglass husk for the new resin to stick to.

 

[ezmobee]

There's a reason why that isn't good but I don't remember what it was. I'm a tin boat guy. I do know it's been suggested numerous times on here and is always shot down.

 

[joepcdr]

There's a reason why that isn't good but I don't remember what it was. I'm a tin boat guy. I do know it's been suggested numerous times on here and is always shot down.

I've got a 56 Lonestar Skipper as well that I tool around on the lake with. The hull plate tops her out at a 50HP motor. If it wasn't for that I thought about putting the mercury engine on her.

 

[Woodonglass]

Trying to put new stingers in the old channels is an exercise in futility. The Stringers ARE the backbone of your boat. The MUST be firmly attached to the hull and there's no way to get a good attachment into the old channels. Unless the walls of the stringer channels are 1/4" thick or more then you'll need to cut em down and start from a bare flat hull. If they are 1/4 inch thick then you can do what you're suggesting. The actual load is carried by the glass and NOT the wood IF the Glass is thick enuf. If not then it's a combination of the wood and the glass.

 

[joepcdr]

Trying to put new stingers in the old channels is an exercise in futility. The Stringers ARE the backbone of your boat. The MUST be firmly attached to the hull and there's no way to get a good attachment into the old channels. Unless the walls of the stringer channels are 1/4" thick or more then you'll need to cut em down and start from a bare flat hull. If they are 1/4 inch thick then you can do what you're suggesting. The actual load is carried by the glass and NOT the wood IF the Glass is thick enuf. If not then it's a combination of the wood and the glass.

I know the glass must be pretty think. Because in areas where I know its rotted for sure and have been able to verify. The glass has been able to support my weight without collapsing. Keep in mind I didn't know the stringers where shot until I got to poking around.

 

[lckstckn2smknbrls]

You mention using Sea cast for the deck too. You can use the sea cast for the stringers only and make the deck from exterior grade plywood. That will save a lot of money.

 

[Woodonglass]

I know the glass must be pretty think. Because in areas where I know its rotted for sure and have been able to verify. The glass has been able to support my weight without collapsing. Keep in mind I didn't know the stringers where shot until I got to poking around.

This is not the point. Supporting your weight is insignificant. The constant pounding on the hull by waves and wakes puts a tremendous amount of stress on the hull Without securely attached wood stringers or thick fiberglass stringers it will not withstand this stress. If the MFG use wood cores it was because they DID NOT want to invest the time and money to make the stringer channels thick enuf to carry the load. You need to either replace the wood stringers or go to the extra expense and labor to build self sustaining THICK walled all glass stringers. I'd recommend the wood ones.

 

[joepcdr]

You mention using Sea cast for the deck too. You can use the sea cast for the stringers only and make the deck from exterior grade plywood. That will save a lot of money.

I spoke with the gal from Seacast again. Because they was telling me it would have to be all seacast solutions. Basically no wood at all. I pointed out to her the other day that it was going to be quite costly if I went that route. Just to do the stringers they quoted me about $475 just for the seacast materials. That's not including the fiberglass I would need to recap each stringer. I emailed again inquiring if I could just do seacast stringers and put a wooden deck on top of that because of the cost of the total project exceeding that of what the boat is worth. She she said it can be done, But if I ever had to redo the wood deck again I'd have to repour the seacast stringers. I guess once you tap it with screws it can't be done again from the sounds of things.

 

[Woodonglass]

That seems a bit high to me. How many stringers do you have? what are their dimensions?

 

[ondarvr]

Either she doesn't know what she's talking about, or there's a misunderstanding about your plan.

 

[joepcdr]

This is not the point. Supporting your weight is insignificant. The constant pounding on the hull by waves and wakes puts a tremendous amount of stress on the hull Without securely attached wood stringers or thick fiberglass stringers it will not withstand this stress. If the MFG use wood cores it was because they DID NOT want to invest the time and money to make the stringer channels thick enuf to carry the load. You need to either replace the wood stringers or go to the extra expense and labor to build self sustaining THICK walled all glass stringers. I'd recommend the wood ones.

I understand what your saying. I realize that if I was to use the existing channels and say I dropped in wood stringers. I'd have to affix them to the hull of the boat in some fashion. Which I basically understand it was originally done with the fiberglass roving and matt. There are no screws or magic glues involved. So I was thinking that if the fiberglass channels that would be left after cutting away the cap to the fiberglass holding the stingers in place, then digging out the wood. Why couldn't a person wrap there new stringer in fiberglass matt. Get everything all resined up all nice and gooey and slide the new stringer in place and recap. To me that would to aid in strengthening things up a bit or am I looking at this all wrong.In my opinion I think it would help to make sure that the new stringer was standing upright like it should be instead of trying to slide all over the place.

 

[joepcdr]

That seems a bit high to me. How many stringers do you have? what are their dimensions?

The boat has a total of 5 stringers. The largest one is basically a 1x6 running down the middle with two outer ones on both sides with smaller heights. I'll have to get the measurements again. They was telling me I would need 11 gallons total. Which in all honesty I thought was a bit much myself.

 

[ondarvr]

The method can work, but frequently the glass work was originally done so poorly that it needs replacing anyhow.

 

[ondarvr]

The boat has a total of 5 stringers. The largest one is basically a 1x6 running down the middle with two outer ones on both sides with smaller heights. I'll have to get the measurements again. They was telling me I would need 6 gallons total. Which in all honesty I thought was a bit much myself.

​Not about the amount, but about doing a Sea Cast deck, and about having to re-do the stringers if a wood deck failed.

 

[Woodonglass]

As I stated, it's not the best plan due getting the new wood to adhere well to the old channels. IMHO it's best to start from scratch. If you want to give it a go...By all means do so.

 

[joepcdr]

I'm just kind of weighing my options for now. I got to get the motor running first or it isn't going to be worth me pursuing. I just got the trigger rewired this evening and opening all sealed back up with epoxy to make it water tight again. Hopefully after all that work it does what it's supposed to. This week I got to create a new wiring harness as the one on the motor is shot!