Stringer Repair 1985 2001 Ski Nautique

Okay ~ Main stringer is out..... I'm concerned. As I lifted the stringer out of its track, I noticed that water was standing in the track ~ from the bow to the stern.

I think this confirms my suspicion that water was accessing the area underneath the floor from the hull.

The fiberglass in many places in the track groove looks black. What should I do?

TX Foilhead wrote: No, that's water that got in the stringer from the foam and holes drilled in it. If water was coming through the hull the bilge would always be full and the boat would have sunk by know.

TX ~ thanks for the quick response ~~~~ I suspect if I had left the boat in the water for 24 hours without a bilge pump operational, the thing just might have sunk.

For the last two seasons a lot of water was getting into the bilge.

The PO had jury rigged a trailer rail with astroturf for carpet secured by 1/2" inch screws with raised heads ~ drilled from the bottom. Shortly after I bought the boat, the screws started coming out. When you'd float the boat on the trailer, these screws would be grinding in the bottom of the hull ~~~~~ in many places the stupid screws created dings that gouged down all the way to the fiberglass mat.

A friend and I rebuilt the trailer about midway through the summer, and also did a gelcoat patch on the damaged spots we could see of the hull. I started noticing the water the next season.

When I was leveling the boat to make this repair, I noticed that at least one of the patches we did had failed, and we'd simply 'missed' another one. There are pictures of a few of these "dings" at the beginning of this thread.

When it first started holding water, I thought it was a problem with the stuffing box (as the owner's manual said that the stuffing box might need to occasionally be tightened, etc.), and never thought much of it. Then I started noticing the floor getting soft in one spot, then another, then the floor separated from the hull on the starboard side, etc.

As I type all this out, I am almost certain I have at least one leak on the bottom. Damage may have occurred topside from water coming through the top, but the bottom needs to be addressed.

I'm wondering and since it will probably come up for Jonathan:

Paul, how did you make that dip between the main and secondary, as shown in this picture of the starboard stringer below? I kept the piece of fiberglass from both sides in case I need to use them as templates, but your design looks pretty clean.

Did you use two 2x's right next to the primary?

My 1st boat (a Tom Sawyer I/O) had cracks right where the bunks were,. so I couldn't easily find them when trying to figure out why I was taking on water.

Maybe you want to float the boat (on trailer) to see if you truly have porosity.

iplan wrote: Okay ~ Main stringer is out..... I'm concerned. As I lifted the stringer out of its track, I noticed that water was standing in the track ~ from the bow to the stern. I think this confirms my suspicion that water was accessing the area underneath the floor from the hull. The fiberglass in many places in the track groove looks black. What should I do?

I don't think this is that unusual. It's pretty common to find the rot at the hull surface, with the top of the stringer ok. Mine had exposed wood at one point where it probably never was sealed. Cracks develop
on stringers, holes are drilled on stringers, water get's in. Gravity does its thing and takes it to the bottom. Poly fiberglass is porous.
if the boat sits in the water long enough, or if standing water sits inside the boat long enough, water is going to get in. On mine, holes were also drileld into the stringers for the swim platform bolts.

Obviously, I would look around for signs of cracks or holes in the hull.

But, finding none, I'd grind out the mess, and put in the new stringers with epoxy resin.

BKH

If I was a betting man I'd say the water was inside and did not come through the bottom.
In the pic below I removed the block they screw the bildge pump too. At this point in the project the boat had been out of the water and in my garage for a year and there was water under it still!!!

All flat bottom CC's that I have dissected used 2x8 primary stringers. Only the v-hulls used shorter ones.

I don't think you need #2, but it will help the glass to stay in place if you paint the stringer first and them lay the glass on the wet stuff. Give it a few minutes to sit and wet in before you add more epoxy. I saw a trick on YouTube using a plastic scraper to move excess resin around instead of a brush, works well and leaves the cloth where you put it.

Alright ~ the layup process is going pretty well. Whoever said it was like painting ~ was spot on.

This morning, I tried to do the top of one of the secondary stringer pieces, and found it impossible to get the tape to stick to the top of the stringer & sides of the stringer at the same time. I'd get the top in place and in good contact with the edge, and there'd be air bubbles on the side. Then I'd lock the sides down ~ which created air bubbles on the tops again.

I finally ended up pulling the tape off, and logging on to post this question: Is there a double secret Ninja-technique I'm missing for taping the edges?

Nevermind~~~~~~ In the time I was up here typing that message, the epoxy set up a bit better, and when I went back out, it was 'tacky enough' to just stick the tape on. I added a little bit of epoxy to the topside fo the tape to saturate it. I think I'm good.

Ive always done zero pre-laminating with wood stringers- all of the layers used to attach them to the hull usually cover them sufficiently. Maybe add one more layer over the top- but thats after theyre glassed down.

Floor panels and tall structural members like bulkheads are another story... whatever wont get a layer or 2 of glass (both sides) in being taped down should be pre-laminated.

Well, I guess I'm ahead of schedule ~~~~~ lol

The plan is to glue them together before placing them in right?

By all means, grind out any porosity or weak substrate from the factory. It doesn't work to put resin on top of already cured mat. It just sits there, have tried it.

Grind the lip away, you should do that anyway before you put the new ones in.

I would, you're going to build a new one with the the new stringer. It sounds like you're adding a bit of work to the process. Get the stringer cut and figure out where you want it, bed it in some epoxy and faire out the transitions to the hull then cover it in fiberglass. No need wrap it first or do anything other than some CPES before it goes into the boat.