1992 Sport Floor Replacement

Unfortunately, it's that time. I bought this boat last spring and got to use it this past summer, but I quickly realized the small spot that felt somewhat spongy, was really a large area that was in need of replacement. Time to replace those stringers. I have done some reading on here and with the size of the job, I originally contacted some local fiberglass shops to do the job. I couldn't find anyone who would contact me back after an initial conversation and none of them wanted to do it to the standards that I wanted it done. All wanted to use polyester resin and plywood. After reading others threads, I think I can get this done myself, the only question is how long it will take and how much help I am going to need from you good folks. I haven't found a thread specifically on replacing a Sport Nautique's stringers, so I figured I would start one. I started a few weeks ago pulling out the interior. The rear seat came out easier than I dreamed it would. Gravity and that one clip is all that was holding it in, just like I had read somewhere on here.

When I removed the passenger seat, where the spongy feeling started, I noticed that the carpet had been cut and when I pulled it back I saw some poorly laid fiberglass. Looks like someone was trying to strengthen the floor at best and possibly hide something.

This past week I did some more work on it and got the motor out.

Then I started cutting the floor up and digging out foam. I am all for the sawzall for this job. We tried one little section with an angle grinder and metal cutting disc. The dust was unbearable. With the sawzall though, no issues. I first cut out the section under the passenger seat and found bits of black stuff that I am sure at one time resembled plywood.

Brent,
You mentioned polyester resin. I suggest going epoxy after the CPES. Yes, as Chris mentioned, you can mix your own by thinning with a solvent.

I looked for Okie Boarders thread. I looked for all the threads started by Okie Boarders in the Boat Maintenance and General Discussion forums. All I found was a thread someone else started with some pictures of the cap being removed. I was not picturing going to those lengths when I started. Can anyone point me to his thread?

More links for reference later:
BuffaloBFN thread
Another BFN Rebuild
1985 2001 Ski Nautique rebuild
'87 Ski Nautique Floor/Stringer Replacement
'83 2001 Ski Nautique
Custom 1965 Mustang

Looks like you can pull it off (not removing cap).   I would dig out foam under the good wood ledge that you are trying to tie into. Somehow clamp a slat of plywood under the lip, glue with epoxy. Then your new wood has some good surface area for bonding.

Some guys use PVC pipe for vent ways. Maybe just leave the old hose in the foam & make a new path.

This is what I did on the Mustang. 3" thin wall pvc for airways and 1 1/2 for wireway and for control cables. Looking forward.

Brent, this is how I did mine.

I was originally planning on running new pipe through the floor similar to what you have done, but because of how close the pipe is to the inside wall of the storage area I am not sure I can cut them out. I am thinking about just cutting the hose where I can get the foam out of the way of the stringer, then putting the pvc pipe inside the hose that is still encased in foam.

Duane,
Thanks for getting back. Just so everyone knows, the common scd. 40 PVC pipe used for plumbing drain waste and venting uses different fittings than the very thin walled underground drainage PVC pipe. Tell me how I know! I got stung years ago piping a gravity return line off a roof cooling tower. Unlike sch. 40 and sch. 80 having common OD's, the underground drainage PVC has a different OD.

Brent,
If you have better than a year, the Doug can be air dried. Ask the mill if they have anyone who kiln dries for them. 8% I consider to be max. Get a moisture meter. They aren't expensive. Don't forget that LVL is an alternate material for stringers. There's a complete thread on it. I believe there's a link in the FAQ thread. I currently have 500 board feet of Red Pine stickered out in the wood shed. It was cut and sawn about 19 months ago. It's now down to around 5% and ready for my project.

Thanks for the link. The composite is tempting, I have a supplier of Coosa board near me, but the time and expense are too much for me. Based on everything you all have posted, it should last longer than the 23 years it lasted this time if I do it right. I already have the CPES, and am planning on using epoxy, so it should.

I found a moisture meter on Amazon with +/-1% accuracy for $24. I didn't realize they were that cheap. I have a few other things I could use that for, so I bought one.

The mill has a kiln, but they didn't offer to dry it. I think I'll call them back on Monday and see if they can't include the four boards they were sourcing for me with some of the heart pine they typically sell.

I searched some more and found a place to supply it. They were a wholesaler so I am going to have to buy it through a local hardware store, but I should be able to pick it up Monday. For anyone in North Alabama, Gobble Fite in Decatur can get Douglas fir from Russell Lumber. It is kiln dried. I am planning to get a couple of 1x6x12s & 2x8x14s. Prices quoted were 27.56 for 1x6 & 87.50 for 2x8.

I am looking at my layup schedule to make my first fiberglass purchase. Here is what I am thinking:

Primary stringers: 2" 8.7oz E cloth, 4" 8.7oz E cloth, with each of these running the length with half on the hull and half on the stringer then 8" 8.7 oz E cloth overlapping 1" on the hull and up the stringer ~5". Over this lay 12" wide 1708 tape that starts at the top of the stringer and runs down onto the hull. That should make it overlap 1" past the 8" cloth. Same on both sides.
Secondary stringers: same application of 2", 4", and 8" cloth and 12" biaxial.
Then drape 7.5oz cloth over the top of the stringers to give them some protection.
For the bulkhead behind the ski locker I plant to use plywood and use the 2", 4", and 8" on the seams to the stringers and hull then drape it in the 7.5oz cloth also.
I am using plywood for the floor and plan to wrap it in 1.5oz mat.

Thoughts? Am I missing something?

Thanks for laying it out on your plans. I was considering paying someone to replace all the wood. After seeing threads on how it should be, I know the price I was qouted would not be to the standards shown on this web site. This weekend, I am plan on getting the floor pulled out on my 1980 sn. Please keep up the post.

MechGat, your last post was April 9th. I'm just curious how it all came out. I just picked up a 92 sport nautique a couple months ago. The floor seems very solid except for right in front of the engine. I hope this is just a floor problem and not a stringer problem. It's not bad but I do want to address it this coming winter and I'm curious what all I'm getting into. I'm pretty handy mechanically and I'm not scared to jump in and rebuild something but I don't like surprises. So, I guess my question is, what would you have done differently, and what did you do that would be good advise for someone with the same boat?

I am working this week on this project. So far I have the secondary stringer shaped and ready for CPES. I also shaped a bulkhead and a piece I needed to replace in front of the ski locker.

Question for plywood floor: is it better to leave the primary stringers full depth and scab a piece on the inside to support the plywood or once I wrap glass over will it become a strong system that losing that top 1/2" won't matter at all. When I think more about it being 1/2" I think that tells me it probably won't matter.