Filling/ Drying Void in Liner

[DougP]

I pulled all my ports to deal  with some leaks. A couple of them have large voids, and there was moisture in them.

I've read the threads about filling the void with epoxy. My question is this: The voids do not appear to be an issue in terms of strength or structure. Why fill them with epoxy? Seems that all I really need to do is fill the void to eliminate a water path. I also doubt I could properly clean & fill the voids (deep or on top of the hole) with epoxy, Instead of epoxy, what about some sort of injectable closed sell foam?

Also, how do  dry the liner out without drilling?

[Stu Jackson]

Doug,

Perhaps you were bouncing off this thread: http://c34.org/bbs/index.php?topic=3601.0

I suggest reviewing reply #8, with its picture.  I assume that you are referring to this condition on your boat.

As noted in the old thread, the idea is to keep the water OUT of the exterior layer and not worry about the voids.

To dry them out I would NOT drill any holes in the interior headliner, but rather use heat, like a hair dryer, to dry out in between.  Then, when you reinstall the ports, assure yourself that you have a good seal and are keeping the water from entering the boat by sealing the ports and the exterior laminate.  It's just not worth filling all the space in the voids.  You could choose to do a bit of filling for the first few inches all around, so that if your seal failed in the future the water would stay near the port and not migrate through the void(s) again.

When I re-bedded the port in that picture, I did NOT fill the void, just made sure the port was well bedded.

[DougP]

Thanks Stu. That's pretty much what I was thinking.

I am still pondering the idea of using an injectable, closed cell foam.  Inject the foam into the voids, then epoxy the exposed edges for a nice finish and good surface to apply sealant.

My thinking is that filling the voids would reduce areas for water to travel or pool. That might make it easier to deal with leaks in the future. The foam might also add some stiffness and insulation in areas around the ports, which may help maintain a seal longer.

What I can't see, is any negatives. The foam is cheap, and would only be in the voids in the head liner. I should never have to worry about cleaning it or removing it.

[Stu Jackson]

Doug, the downside I see about the foam is that it expands.  I have a can of foam on board that I was going to use for the icebox insulation, and have not used because of my concern about expansion.  Since our water temps here are 57 degrees year round, and we have a large inverter charger and now a new alternator regulator, I have put that on the back burner, knowing the house bank can keep up with the amp load of the fridge on longer excursions.

"...thinking is that filling the voids would reduce areas for water to travel or pool. That might make it easier to deal with leaks in the future. The foam might also add some stiffness and insulation in areas around the ports, which may help maintain a seal longer."

The concept is to keep the water out, and in that regard the foam will do nothing.  Stiffness and insulation is not the issue, waterproofing the port(s) is the only way to keep water out.

Your choice, but I wouldn't use those reasons to use the foam.  I would think that the only reason would be for the foam to act as a "base" to put in the epoxy.  Once the water gets in, the idea is to keep it limited to the interface of the port and the fiberglass part of the hull so it doesn't get into the voids.  Adding foam covered by epoxy or epoxy only at the opening seems the way to go.

[Ted Pounds]

Try using Gorilla Glue.  It's same as the foam (polyurethane?) but only expands a little.  It will make a water proof coating inside the void.  Just a thought...

[DougP]

For what it's worth- i just checked Beckson. They recomend filling the void with foam.

[Stu Jackson]

Doug,

I appreciate their recommendations, although I tend to disagree, because I do not know what absorption the foam has, while I am sure that the epoxy has NONE.  If the foam can absorb moisture, then it's the wrong material to have IF water ever gets in again through your new bedding sealant.  I still recommend that if you're going to use foam, unless it has the same water repellent properties as the epoxy, then either do nothing or use the epoxy with or without the foam.

[Stu Jackson]

Doug, another independent source recommends epoxy, see the May 2007 Mainsheet magazine, Tech Notes, page T9, C380 section, "Portlight -- Resealing & Reinstalling."  Recommends epoxy to fill the voids around the core.