Wet foam in 1996 ski nautique, best way to get it out?

[ScottStewart]

So I posted a while back concerned that my wake wasn't great on my 96 ski nautique, and it always felt like the boat was low in the bow. To satisfy my suspicion I took the boat to a weigh scale and it came in 500lbs overweight.....I calculated gas, oil, stereo etc. In any case decided to take the plunge and drill a few holes. First up in the bow.....soaked foam, next rear port....dry, next starboard.....wet foam. The floor is fibreglass and my question is has anyone encountered this in a 96 or above with all fibreglass stringers/floor. I would like some help on the best way to remove the floor and if I need to replace the foam once I remove it. I believe I have to along side the engine as its used as support for the floor, but up in the bow nobody will be putting any weight on it so wanted to just leave it out. Can I do this? It would be great knowing the stringer layout under the floor so I knew where to start cutting. I suppose there is one more question.... how the heck did water get into the closed bow???? I have read possibly through the battery box but mine looks solid (no cracks). Any help/tips would be greatly appreciated as I nervously start this crappy job.

[DanielC]

One possibility is the screw holes for the fins. Remove the screws, see if water runs out.

[Mamigacz]

Have you ever left the plug out, or allowed the bilge to fill up to excessive levels? Sometimes large amounts of rain can pool in areas where the floor joins the sides of the boat. In perfect world, with a perfectly sealed floor, this should never happen. However, when water is pooled by a crack or an unsealed seam it will find its way in to the cavities where the foam is. My best guess is the bilge had a lot of water in it, when you slowed down the water rushed to the front of the boat and spilled over the stringer (through a crack or seam) and into cavity in question.

As far as replacing the foam with new, there is one big risk. If your boat capsizes or fills up with water, it will most likely go down. The foam is supposed to keep it swamped and floating. When the foam gets wet, it becomes useless. There are a lot of people that don't agree with this, but when I did a floor replacement on my previous boat, I did not replace the foam. I understand that the boat will be at the bottom of the lake if it fills up with water, but water always finds its way into the foam cavities eventually. You don't have to worry about this with a fiberglass floor, but with a wood floor and wood stringers, the wet foam accelerates floor and stringer rot.

I have never done a fiberglass floor removal. Hopefully someone else will help out with floor replacement tips.

[DanielC]

Correct Craft used to make a short video on how the boats were built. If I remember, the bare hull had fiberglass stringers that were also foam filled, laid into the boat, and then fiberglassed in. After that, the remaining cavities were filled with foam, the top was cut off, and sanded level, and the floor fiberglass floor was put on top of the foam. Then carpet, engine frame, and the boat was finished.

The foam does add structural strength. I would not omit it

[TRBenj]

There are many stringer rebuild threads on Correctcraftfan.com that you can gain knowledge from. Only minimally invasive floor repair has been documented on a glass stringered boat, but I dont think the composite structure changes the equation too much. Many people (myself included) have rebuilt older Correct Crafts and decided to forego the under floor foam. DanielC is correct in that the hull-foam-floor sandwich does add a lot of strength to the structure, but that strength can be replaced by other means.

This sounds like a very interesting project- please pop your head in over there and start documenting your plans. And take lots of pictures!

[mnwakerider]

I just did a battery box enlargement on my 03 SAN and the further down to the hull I went the wetter the foam was on my boat. I wrote it off as a lost cause.

My dad and I removed the foam in an old dingey/catamaran boat that we bought when I was in grade school. That was one of the worst projects I ever remember; we cut port holes to fit one arm in and scrapped and scratched that crap out. It took days and days and the boat was only some 8 feet, with two fiberglass pontoons that were filled. That would be an intense project to remove it all in your boat.

[Marko1956]

I looked into this last year with a 92 American Skier. The proper way to do it is to remove the seats, engine and all of the flooring. You then install new flooring, cut 3" holes in it and pour in expandable foam. You cut off the excess, re-fiberglass the access holes and then re-install everything. Not a job for the causal observer, but not difficult if you have the time and space. Re-aligning the engine and shaft requires special tools. The price I got was about $2500, not including engine re-alignment and new carpeting. Well worth it if the boat is in good condition.

[ScottStewart]

Thank you Daniel! The front tracking fin was replaced before my ownership and I had my suspicions if it was sealed correctly.......I pulled the first screw out and water is pouring out of the hole. AAAARRRRGGGG!!!!

[ScottStewart]

foam replacement

What else can I use besides foam for structural help?

[Mamigacz]

I'm sure there are better idea's, but I glassed in 2x8's (wrapped in fiberglass) along the sides of the boat. I did end up using multiple pieces to get close to the contour of the boat sides. This gave compressive support by the stringer and the newly added 2x8's. The 2x8's had to be ripped with a table saw to get the correct floor height. It was very solid, even though the center had nothing supporting it.

[TRBenj]

I would not use wood in a composite boat!

Again, I highly recommend heading over to CCFan to start a discussion on a reasonable path forward. You will get MUCH better information over there.

[ScottStewart]

Thanks for everyone's help, and TRBenj, I will fire off a post on CCFan as well. Thanks again, I have pulled all the foam out of the bow and am moving backwards.