advice for water soaked foam

[Ebwalk]

I pulled the tank from my '87 Mako 23' and guess what? No appreciable crevice corrosion despite horribly soaked water-impregnated foam. (I'm still inspecting it, but nothing obvious) well I am this far into it, I am going to replace the tank anyway. Here's my question:

there are six 3" holes in the floor of the coffin, probably to push in the foam. Well, that foam is completely water soaked. I don't have it in me to pull the hull from the deck and totally strip out the bad foam. Is there an interim fix that i can use to remove most of the bad foam? Can I cut more holes in the floor of the coffin or is it structural in some way? Thanks for your thoughts.

[Triplecrownnc]

A lot of us cut out the coffin, removed the wet foam, glassed the coffin back in, foamed through those holes, glassed over the holes, put in new tank and foamed in the tank.

[Ebwalk]

Ok, sounds reasonable. Makes great sense to glass over the holes after foaming! The tank vendor doesnt want the tank foamed in I was thinking about trying to stick a small bilge pump in there to drain it. But maybe I can make a drain hole to the bilge

Is there any way see the pictures In your project? They all have some photobucket error?

Thanks again.

[Triplecrownnc]

quote:

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Originally posted by Ebwalk


Ok, sounds reasonable. Makes great sense to glass over the holes after foaming! The tank vendor doesnt want the tank foamed in I was thinking about trying to stick a small bilge pump in there to drain it. But maybe I can make a drain hole to the bilge

Is there any way see the pictures In your project? They all have some photobucket error?

Thanks again.

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Yeah, had a pretty extensive resto, all the pics are lost in the PB mess. I cut the coffin around the perimeter maybe 6 inches below the top edge. It still would not come out so I had to cut it in half.

You should call Sunshine Marine Tanks, they are our preferred tank supplier. They will coat your tank in coal tar epoxy and send it to you. There is no issue with foaming in these tanks. If you have the tank sent to a business address shipping is reasonable.

Its the classic question, do I put a drain in the coffin? Most of us have elected not to, there is just no good way to do this, remember, if there is a connection to the bilge for water to drain away from the tank, it can also back up to the tank, and it will. I had a drain that takes water off the top of the tank to the bilge, not low like you seem to be thinking.

The key is to seal it up and then maintain that seal. Silicone doesn't last forever. Essentially that is what has happened to these older boats, tank lid on at the manufacturer, sealed up and not looked at for 30 years. I pull my lid every 2-3 years, clean the top of the tank and get a fresh seal on there.

A lot of us trimmed the expanded foam around the tank flush with the top of the tank then glassed over that junction.

I have just completed this cleaning and resealing, maybe I'll post some pics of what a well maintained tank looks like after 3 years unchecked.

[Prater]

I just ordered a tank from Sunshine, they were great to work with. I pulled two tanks and replacing with one larger tank. I also used a chemical from Fiberglass Coatings that you pour into the foam and let set a few days, it does not melt the foam but it turns it mushy and causes it to lose its bond to whatever it is stuck to. I was able to pull my tanks out by hand.