Wet Foam!

TRBenj wrote: It doesnt take much for water to get under the floor- a small crack or screw somewhere is enough. The good news is that there is no wood to rot (1993+). The foam is also closed cell, so it wont absorb water very easily. When I replaced my rotten stringer in my '90, the foam surrounding it was surprisingly dry. I believe my rot travelled down the stringer because the water had nowhere else to go.

351, Tim is correct that it doesn't take much for water to get in plus polyester resin absorbs water so there is no such thing as encapsulation of wood. (one of the reasons epoxy is recomended on a stringer job-no water absorbtion) Just because the fiberglass around your stringers is solid, doesn't mean the wood isn't rotted. It means that back in the 60's they layed plenty of glass around them. You will need to check some more. I may have missed it but did you check to see if the lag bolts on the mounts turn? You have had 5 people in this thread all warning you about rot. Why are you fabricating motor mounts over and above the factory? The simple lag bolts worked for 90 years! We are simply concerned.

you can plan on the foam being soaked, just because the stringers are composite doesn't mean sh*t water is still going to get to the foam, especially after sitting outside uncovered for two years.

I just bought a boat that was stored outside for 2 yrs. It is a 1994 Ski Nautique. the seller told me this year has a total fiberglass hull and stringers so there is little risk of rotting stringers. is this true. I think there may be wet foam but I am not sure. Can anyone add some advice as to what to do first to check for wet foam and if the assertion of fiberglass stringers is correct? tom 814-883-6735

Here is my current tale of foam ...

I just picked up my 66 Mustang from the repair shop where it has been for the past year waiting for a repair on the lower end after sheering off the rudder on a rock when the lake level was down 2 years ago. Never could find the rudder, but did find lot of props and and outboard lower end assembly near the rock. I was not the first! Had to replace the rudder, port, drive shaft, and strut. Believe it or not, the prop was able to be repaired and loooks new. Insurance paid for everything with no on site inspection.

However in replacing the port, which was damaged, as the rudder shaft would not come out, the area around the port had delaminated and needed to be reglassed. In doing so, it was noticed that one of the exhaust hoses had a hole in it, thus pumping CO2 and water into the boat. Also, when alligning the engine bacck to the new shaft, the shop found that the lag bolts on 1 of the motor mounts was soft and suggested that a bracket be fabricated or the engine would move out of allignment. So, it sounded like I still needed to replace the exhaust hoses and fix the motor mount before putting it back in the water.

A neighbor has a restored 65 Mustang and offered to help fabricate the motor mount brackets much as he had done to fix the same motor mount issue in his CC. Brackets are U shaped with 2 horizontal through bolts in the stringers instead of relying on the factory lag bolts that bolt through the top of the stringers. From a mechanical standpoint, it is far superior to handling the engine torque.

So, I picked up the boat and started to open the floor to attack the hoses. However when we opened the floor, we found it was solid foamed. Good news was that it was the open cell type, so it comes out with a putty knife quite easy. Bad news is that when we dug down, we started to notice water and gasoline. The gasoline came from the fact that when I bought the boat, it still had the original stell gas tank in it which had a small leak in the end seam. Did not notice it when I inspected the boat, but my wife always maintained the smell of gas/exhaust in the rear of the boat was bad. Now, I know why. So, now we have faom that is saturated with water and gasoline. No turning back now! Now the worry is if the stringers are rotted. Well, we got out the rear 2/3 of the foam and the stringers are all OK and the glass around the main stringers is still solid. The secondary stringers were also in good shape, although the glass has delaminated from parts of them. However, the cross bracing for the floor are rotten. They were never glassed and the previous owner replaced the flooring with plywood used for truck semitrailer walls (has plastic laminated to each side).

Neighbor maintains his 65 Mustang never had any foam and still doesn't and he is reccomending that I don't replace the foam, as it. He thought that the previous owner foamed the boat and used the wrong type of foam (open instead of closed cell), buit in reading through the forums last night, I belive it is factory, as I saw references to CC using open cell foam in the early 60's.

Planning to remove reaming foam in the front of boat today and start evaporating the fuel and water out of the boat.

Bottom line -
1) We are damn lucky the boat never caught on fire. The only thing that may have saved us, is the mixture of water and gasoline in the foam would not be condusive to burning.
2) If you have open celled foam, get it out out, or you are asking for added weight and potential rot. Only God knows how old the water is that was sitting in the boat.
3) Besides the foam retaining the water, the open cell foam actually made the water problem worse, as the foam blocked the ability of the water to drain from the areas outside the main stringers into the bilge area.

I have taken some pictures and will attempt to post them, as an update on how the repair on the 'hole in the water' goes.

Want to see what it looks like when you get all the foam out and repair/replace your stringers?

www.78skinautique.zoomshare.com

It's a big project, but you dont want to take your chances with the alternative. In a worst case scenario, the stringers fail to hold the motor mounts and let the motor spin freely under the dog house. The motor, now free to be pushed by the thrust of the propeller, can leave very little room for you and any passengers in the front. It would be a rare event, but I wouldnt mess with murphys law in this case. Get that foam out of the floor ASAP and find out how much damage your stringers have seen.

I would check your motor mounts and see if they spin freely.

If they do you NEED to replace the stringers before you do damage do your driveline and hull.

If they still have bite to them I would wait till winter and tear up the floor and check out the foam. Most likely even then you are going to find rotten secndary stringers.

Big Jim Slade wrote: Is it somewhat likely I could find the stringers are OK, and just the foam is done for?

Id say no. If you have some wet foam under the floor, chances are good that water has found its way into a stringer (or all of them). If you do find the stringers to be miraculously dry, then yes- you could replace just the foam.

Check the tightness of all the motor mount bolts where they attach to the stringers. If most are solid and dont spin freely, Id say youre safe to run the season as-is.

Jim, If the stringers are bad, then you run the risk of damage to the trans and drive line. Have you checked for rotted stringers?

your just going to be carring extra weight around. If you plan on redoing stringers and floor during the winter, don't see what it would hurt to wait a little while longer.