Does spray expanding foam absorb odors?

May 27, 2025
5
Hunter 356 Monterey
Hello Everyone

New owner of a 2002 Hunter 356.

A previous owner sprayed expanding foam into the space between the hull and the shower pan in the wet bathroom. When I purchased the boat the head was leaking and a mix of urine and water was draining into the shower drain. It turns out the head wasn't sealed to the pan and so that liquid was also leaking into the bilge via the lag screw holes holding down the head. The urine odor in the head is remarkably overpowering. Looking online I get mixed information about whether or not that foam is absorbent. Might anyone here on the forum have experience or views about this? Removing the foam would require cutting a large hole in the shower pan and so I don't want to tackle it if it's not necessary.

Thanks,
Jim
 

PaulK

.
Dec 1, 2009
1,375
Sabre 402 Southport, CT
Some expanding foams may be closed cell. Some are not. We had expanding foam in the bilge of our center console skiff, for flotation. It was not closed cell, so it absorbed any water that got in there. The boat ended up floating six inches below its waterline because of the extra weight. We ended up cutting out the entire deck and removed the foam by digging it out with a garden spade, one dripping ten pound shovelful at a time. It sounds like you need a tool to cut open the pan, a carbon filter mask, goggles, heavy duty gloves and some knives for cutting out foam.

P.S.: if you can cut the pan out in one piece you may be able to 'glass it back in when you're done. It would be much quicker than having to rebuild the pan from scratch.