Water logged foam.

[Old Ironmaker]

This morning we started to pull the floor from a pals new to him 86' StarCraft. It is bad, you can actually pull chunks out by hand and some plywood from a previous butchered patch job actually came up with the carpet. Here is the kicker all. The factory foam between the rotted stringers is as dry as a bone, no moisture, nothing. The boat was in the water no earlier than early September. Most of the wood is still wet to the touch. The foam is bone dry. I said that. I have read here on several threads that closed cell insulation can not take on water, others say yes it can. I was in the Sunroom business and our wall panels were closed cell, I know my foam, this is closed cell. The foam under the gunnels are open cell, similar to a coffee cup. The floor foam has a sheen to the outside and is very dense. I drove a 3/4" wood drill bit into a piece and it is dry. Like I said I have read threads here discussing whether closed cell expandable foam can become water logged some say yes, some say never.

Just an observation I wanted to pass on. I will try and get pictures from my phone to this PC. I have some problems doing that from my not so smart foam and camera, I'll try with the laptop itself perhaps.

Johnny D

 

[Scott Danforth]

closed cell foam breaks down with constant contact with water. the freezing, thawing cycles break down the cell walls.

rip it all out, start over. go boating.

 

[Old Ironmaker]

This foam is tight Scott. No cracks or signs that it has been infiltrated with water. That includes where the foam touches the bottom of the hull. Other than the outer skin that has formed which is a bit darker the inside of the blobs of foam is the same colour throughout.

 

[rallyart]

Wet stringers and good foam would likely be from bilge water entering cracks or bad seams at the side of the bilge or from low engine mount holes not sealed well. Great if you can still use the good foam but see if you can find and remove any joints that were issues before you glass in new stringers. Good Luck. It's nice for your friend to have someone willing to help with a yucky job.

 

[Scott Danforth]

foam is cheap, trying to work around it to save it is a fools folley

trying to save $30-50 worth of foam on a $1500+ project (not to mention the hours of time wasted to work around it) doesnt make sense

if the stringers are bad, tear everything out, start over, go boating.

 

[Old Ironmaker]

Wet stringers and good foam would likely be from bilge water entering cracks or bad seams at the side of the bilge or from low engine mount holes not sealed well. Great if you can still use the good foam but see if you can find and remove any joints that were issues before you glass in new stringers. Good Luck. It's nice for your friend to have someone willing to help with a yucky job.

Thanks for the reply. All the old foam is coming out. It would be impossible to replace the stringers without digging it all out. The foam was injected at the factory after the floor was installed. Yea this job has sure turned out to be bigger than thought. Pulling a mushy floor out of a boat is like opening the can of worms, a big can. The new floor will outlast his lifetime and mine if done right. Once all the crap is cleaned out hopefully we will discover how the water got in there in the first place. It is a fibreglass StarCraft. The boat looks mint other than it is rotten to the core where one can't see.