Stringer Foam

[flyingfrizzle]

Originally Posted by kmoose

I think a lot of project boat spent too much time in the back yard before they are sold and fill up with water. I've seen it a bunch of times and most people think nothing of it as they have no intention doing the rebuild.

I for one am not a big foam fan but I don't think all the rehab of foam done is that necessary. If the foam got wet, it can get un-wet if drain and vent holes are made and the hull is kept open and dry for sufficient time. Once it is all dry, glass the holes and move on with the build.

I agree with moose, I have done this before as well. Cut holes at the lowest point in the rear of the stringers and set the trailer high as I can get it in the front so it would drain out. A good dry summer with the boat under a shelter it will eventually come out.


I have a hull Im doing for a friend and cut the rear of the stringers off to do the transom and have been letting the box stringers drain out this way. Most of it came out but we have had such a wet winter here in NC that it still is somewhat damp at the bottom inch or two. Hope by time it gets warm enough to start glassing it will be drained out completely. If not I may dig it out from the back forward till I hit dry foam then re-pour. Don't want it to hold me up and don't want to trap water weight in the stringers either as I plan on sealing them up 100%.


I do think the newer closed cell foam is better than what was used 40-50 years ago but if not sealed up all the way water can still get around it or settle in the bottom of the stringer cavity. It may not soak it up like the old 4lb stuff from the 70's but wouldn't trust it to be perfect 50 years from now in the future either.


Nice clean new foam is good to ease of mind and great if you don't want to wait for it to drain out but not always necessary.

[ricknewman]

When I pulled my deck out last week some rain got into afew of the holes at the tops of my stringers as well..I don't think I'm going to bother with opening that can of.worms.What are your thoughts?

[rcoster38]

Originally Posted by ricknewman

When I pulled my deck out last week some rain got into afew of the holes at the tops of my stringers as well..I don't think I'm going to bother with opening that can of.worms.What are your thoughts?

Are you planning on replacing the deck? If so, now is a good opportunity to raise it a few inches. I cut the tops off my stringers, dug out all the foam. things are drying out now while i build forms around the stringers, then will overfill the stringers with new foam and glass the tops back on. took me about a day to cut the tops and get all the old foam out. not sure if my foam was especially wet but i pulled well over 200 lbs of waterlogged foam out of my 20SF

[rcoster38]

also I found that even if the foam near the holes seemed dry, the bottom half of each stringer was basically completely waterlogged

[ricknewman]

Wow, my stringers look to be in good shape but you've got me worried now. No way to tell unless I cut into them I guess. What about drilling 1" hole in the bottoms? That would be easy to close if all is ok.

[Kraken]

My stringers were dry on top. I drilled 1” holes at the lowest point and water came pooring out. I dug out all the foam and reglassed the stringers. I then drilled “weep” holes at the lowest points, just in case.

[linesider36]

I'm redecking my '79 23'cc and the stringers were full of saturated foam all the way to the bow.My stringers also had the 1" holes on top but otherwise were sealed. Could condensation account for all this moisture?