stringer help

[NeilMcg]

Considering replacing stringers on my 87 SunSport. Before diving in, however I wanted to know what wood is used. I thought stringers were solid cuts, but I've heard talk about 3/4 ply. Also, what is the engine mounted to?
Tryin to figure all this out before getting into trouble.
Thanks

[Mani]

I had mine done with 3/4 ply, but if you look at the ones that did it with high grade stuff (ie Okie Boarder), you could use douglas fir. Douglas fir is a strong wood used for structural support. One of the local shop owners I talked to told me that he owns an 86 Sunsport like mine, and when he did his he used douglas fir without knots. Problem is you're looking at $600+ for every plank of wood if you go that high grade, but the bastards will last a long time.

[Okie Boarder]

It kind of depends on what you have available in your area. If you can get good pieces of doug fir that'sa good way to go. If not, if you can get plywood, you can laminate it and work with it from there. Check to see what is in your area and see where you need to go from there.

[SUPRALUVIN]

do you have to replace...or repair? Mine were pretty bad but I injected a rot inhibeter which hardened the rotten wood right back up....I then clothed and fiberglassed....easier to save your existing stringers if they are not too far gone.

[Ironcross25]

+1 ^^ I am in the process of doing the same thing. Im lucky they wernt to bad

[NeilMcg]

Luvin,
You've thrown an interesting idea on the table. I'm not 100% sure the stringers need replaced. I have soft spots here and there and considering the age of the boat (87) I thought it would be the best thing to do. However, maybe your idea would work. I think the big thing is (and this is the novice in me) is that I thought stringers were something like 2x4's or 2x6's, not 3/4" plywood. I'm also trying to figure out what wood the engine mounts are bolted onto (I can't see an inboard engine connected to 3/4" wood.) I'm concerned about tearing up the floor and starting a project without having an understanding of the basics involved.

[Ironcross25]

Neilmcg,
I am dug into my boat now. I have ripped the floors up and cut all the tops of stringers off including motor mount area. The motor mounts are basically a bunch of plywood pieces put together. I have been drying the boat with a dehumidafier. The passenger side motor mount was shot. I pulled the wood out by hand. My plan is to continue to dry as much as possible then inject the decent wood with cpes penetrating epoxy (rot doctor) the resin fill over to seal. I then will fill all my voids with seacast ( reinforced fiberglass composite). I will post up some pics when I can. I am still in drying phase but it has dried out a ton in 2 weeks. foam is totally dry and stringers are almost. Its a narly scene when you pull the floor. I am getting a new boat in a few years and I didnt want to spend a bunch of cash redoing everything, but when Im done she will be good to go for a long time.

[wotan2525]

I hate to be the guy with the bad news but I think you guys are being pretty optimistic about a cheap/easy fix. Fix it right or do it twice. I tried the rot doctor/CPES stuff myself before I replaced the stringers. It didn't seem possible that I'd ever get it dry enough and the rot doctor himself says that stuff won't fully cure or penetrate if there is any moisture at all. Finally gave up on it and started cutting. It's a shitty/expensive job and I didn't do as thorough or complete of a tear-down job as many members on here. My feeling was if the factory setup lasted 20 years, my repairs (with a few modifications) should last close to that long.

My CPES experiment ended with the engine shifting away from the mounts, the drive shaft wearing a hole through the shaft log and a hull breach that resulted in a sunk boat. I hope you have better luck.

[Okie Boarder]

I would agree with wotan. A lot of the methods you're considering are band-aids. It also seems like it will take near as much time and expense just to buy you a year or two. In addition, there is still doubt as to whether it will hold up and you risk the same outcome wotan had.

The main stringers should be solid 2x material from the factory. The engine bolts directly to that. The build up around the engine mounts to create the doghouse cover space is a stack up of wood...could be 2x or plywood. The secondary stringers will likely be 1x or plywood and there is a combination of woods used for cross-supports.

There are several schools of thought on rebuilding. I don't think any of them are the "wrong" way to go, especially if done correctly.

[sybrmike]

I agree with all the above. Shortcuts are just that. If you're going far enough to access the stringers, then might as well do it right.

My original structure consisted of dimensional lumber for the inner stringers and cross braces with plywood outer stringers. My engine mounts WERE hollow with the mounts bolted to a single layer of plywood on the top - never seen that before, but still tight after 20 years. Never know what you'll find down there.

I went back with 3/4" exterior (not treated) plywood all around. Two layers with glass in between for the inner stringers, one layer on the outers and cross braces, and built up the mounts solid with several layers of plywood and glass. Dimensional Fir and some other woods are nice, but ply was cheap and available. I went foamless like Okie (another topic of debate), but figured correctly done with updated materials, I'm better than new.

[Salty87]

i have to agree with the 'do it right once' crowd. another issue you'll likely face is wet foam. once foam is saturated, it won't dry out.

there's no way to know without digging deeper...either open her up and hope for the best or start drilling test holes in the stringers. if you find solid wood, you can seal the hole up. if you find dark gunk instead of sawdust on the drill bit, the wood has rotted and there's little you can do. another test is to use a hole saw to open a bigger hole...under the spotter seat. cut the hole, use a section of pvc that you've made serrations on the end so it will dig foam out, inspect for moisture.

you'll face more of these dilemmas...pull the top cap? pull the engine? what type of resin/cloth/wood?

take your time and don't get overwhelmed. these boats weren't built by rocket scientists. you'll probably laugh (or cry) at some of the 'techniques' you find the factory used. i think they made alot of it up as they went.

[smoothfootn]

you'll probably laugh (or cry) at some of the 'techniques' you find the factory used. i think they made alot of it up as they went.

On that note, I'm replacing my floor and I cannot understand the logic @ the factory. Using wood in the boat is a fine idea especially when it is encased with fiberglass. BUT, the only places where the floor was rotten is where they decided to run a damn wood screw through that nicely sealed floor....Back seat is attached with 8 wood screws. Doghouse base is attached w/ 4 wood screws....Driver's seat is attached with 8 wood screws. That water collects in those areas and goes down the threads right into the wood. Don't you think they could have at least put some stinkin silicon around the screws when they put them in....
Sorry, I just needed to vent. It seems to me that alot of our labor could have been easily avoided if they would have done a few more things right!
b

[jet]

Great thoughts going around here, and I wanted to be connected to this thread. Guys Im doing a in-between resto job on mine. No cap off..but all new from passenger seat back, I pulled my floor up in the nose and it was 100% dry. The guys are right. I redid my top only 6yrs?? ago and this last year I had 1-little spot under the passenger seat that I didnt replace and It loosened up and now Im doing it again. Didnt need to but now I want to. Okie can you ad your thread link so these guys and I can go over it once again. Thanks for all of your help guys. Jet