Determination of foam type?

[Boomyal]

If you stick a prybar into old foam and it fizzes and oozes water like a watermelon, would you say it is closed cell or open cell. What year do you think that closed cell foam came into common usage? <br /><br />I just hacked and pried all of the foam out of my gas tank well and I was about take it in and run it through the juicer. It had different levels of moisture in different places but it was definitely wet. The foam is 1975 variety.<br /><br />Those ping pong balls are lookin better and better.

 

[JasonJ]

Re: Determination of foam type?

It may have been either kind. I know over time even the most water resistant foam can eventually absorb water. I don't think a true waterproof foam exists. All we can do is make sure to minimize the conditions that allow for water to stay present in the bilge.

 

[Boomyal]

Re: Determination of foam type?

JJ,you mean like keep your boat out of the water?

 

[12Footer]

Re: Determination of foam type?

LOL. I hear ya! My project boat was more of a waterlogged 1800lb surfboard than a vessel. I don't know how to tell the difference, except that "closed"cell forms a skin after it kicks. but cut that skin, and it's just am atter of time before the closed bubbles drink it up.<br />I'm seriously considering leaving all floatation out of her.

 

[Winger Ed.]

Re: Determination of foam type?

Originally posted by Boomyal:<br />oozes water like a watermelon, would you say it is closed cell or open cell. <br />Those ping pong balls are lookin better and better.

That sounds like open cell, but the 2 part closed cell can absorb water like that much faster than it should if it isn't mixed properly.<br /><br />Back in the 90's I rebuilt a 1968 21' Alum. hull that had been full of rainwater for at least 2 years. The 2 part in it the factory poured in the bow area was still fine. The white slabs of styro. under the floor felt like you were picking up blocks of wood.<br /><br />Something most folks don't do when foaming is leave a place where water can drain out or a means for a little air circulation. That's why all these floors and stryo. rot & waterlog in the first place.<br /><br />If you pour the area around the tank again, it'd probably do better if you left a hollow place under the tank along the keel so bilge water could get out and a little air could circulate. <br /><br />Ed.

 

[Boomyal]

Re: Determination of foam type?

If you pour the area around the tank again, it'd probably do better if you left a hollow place under the tank along the keel so bilge water could get out and a little air could circulate

Definitely Winger Ed, I haven't figured out how to accomplish that yet but that is a must do. I'm also going to put a drain hole (w/ removeable plug) in the forward bilge/rear tankwell bulkhead.<br /><br />I only had a small amount of foam under the tank, maybe two inches. I filled up about 3/5ths of a trash can with it and it is quite heavy.<br /><br />12footer, I wouldn't leave the foam out. I'd try to accomplish what W.E. recommended. The foam adds safety, strength and sound absorbsion. I think it would be pretty drummy without it.

 

[Bondo]

Re: Determination of foam type?

Soda Pop Bottles................. <br /><br />Plenty of Drainage..........<br />Plenty of Ventalation.........

 

[oddjob]

Re: Determination of foam type?

 

[JasonJ]

Re: Determination of foam type?

Yup, never use the boat, put it in a garage, and it will never get saturated again. All it takes is a cover. So many people skip that little process and wonder why the boat is rotted. Water once in awhile isn't a big deal, being left in the rain and snow every day is a big deal.<br /><br />Hey Bondo, I have a bunch of 2.5 gallon plastic jugs in my basement. Yeah, they are industrial herbicide jugs, but they have been triple rinsed and are clean. While I am a big fan of foam, I may come across a project that is perfect for these jugs.

 

[Bondo]

Re: Determination of foam type?

Hi Jason,<br />2.5Gal is Pretty Big, for Stuffing into the Bilge..........<br />Even in my 25'er.......<br /><br />Find some Fishing Nets,+ Build Yourself an Island......... <br /><br />12oz. Soda Bottles though........<br />They'll Squeeze into the Smallest Places............

 

[Winger Ed.]

Re: Determination of foam type?

I haven't figured out how to accomplish that yet but that is a must do. [/QB]

Something I've done over the years is make fibergalss cardboard for lack of a better term.<br /><br />Put a piece of soaked down fiberglass cloth or thin mat down on a piece of wax paper layed on a flat surface. Or, you can make a tunnel by laying the stuff over a wax paper covered board. It turns loose after its set. For complicated things, make a mold from cardboard, tape wax paper over it, and go from there.<br /><br />When it hardens, you've got a thin material you can cut with big scissors. Shape/Cut it to make a roof for your ventilation space. Glue it down with resin, pour your foam, and set the tank.<br /><br />I've used the heck out of that technique, and its always worked real well. <br /><br />Ed.