Best Method for expanding foam installation

[brianmax]

I have seen two methods used here and on youtube to get the expanding foam under the deck..when replacing a deck.

One is to pour the foam into the wells between the stringers and ribs and cut down to make it flat with the stringer height.

The other is to install the deck, drill holes in it, and pour the foam through the holes.


What is the best method?

I am restoring the stringers and deck in a 1989 Ski Centurian. Thanks

 

[83mulligan]

Re: Best Method for expanding foam installation

I don't know if one is "best" or not. I think its to each his own.....However, I think the foam installation in Bob's "timid but determined glasstream resoration" thread is a great method. It's what i plan on doing if i ever get to that point.

 

[Jacket4life]

Re: Best Method for expanding foam installation

Second mulligan. If you cut it, you have to seal it. Seems more logical not to have to deal with that step, to me.

 

[jonesg]

Re: Best Method for expanding foam installation

I'd pour the stuff overboard.

 

[Bondo]

Re: Best Method for expanding foam installation

I'd pour the stuff overboard.

Ayuh,.... Agreed,.... Not using it at All is the Best way....

Whatever you do,...
Plan for,+ allow Drainage to work for you...
Otherwise, you'll be doin' the Whole job again in a couple years...

 

[Bob_VT]

Re: Best Method for expanding foam installation

We have a "how to" and other foam subjects covered here http://forums.iboats.com/showthread.php?t=288451

I agree with "most" remarks above and I will add in this....... do it in small increments or you will have one huge mess!

 

[mogfisher]

Re: Best Method for expanding foam installation

I vote for the pour in place through holes method. Simply because the stuff isn't cheap and any foam you cut out is waste.

 

[brianmax]

Re: Best Method for expanding foam installation

Very good point! I believe I will follow the cut-hole method. What is the best practice there?
What size hole is best?
What is the best method for cutting out the hole so it can be replaced easily/effectively?
What is the best method for plugging the hole?

 

[Allbutwet]

Re: Best Method for expanding foam installation

I used 1 1/2 inch hole saw. Then as the foam expanded put the plug back in the hole. And held in place until the foam stopped expanding.

 

[109jb]

Re: Best Method for expanding foam installation

I used a 4" hole saw. I figured the bigger thee better for not pouring it all over the deck. I spaced them about 3 feet apart from front to back. I raised the bow up in the air and poured the foam in filling from the back to the front. I only mixed about 1/2 gallon at a time (1 qt each part), let it expand and begine to cure. Did next batch. And on and on. As the cavity filled the foam would get to the holes starting with the rear ones. When it got to a hole, I put the plug in with a board on top to hold it flush. The board on top was screwed to the deck and to the plug. Kept going this way until all the cavity was filled. The last set of holes I just let the foamm expand through and cut it off flush after cure. These were in a spot that was not going o be walked on. I did all of this before I glassed the top surface of the deck, but it was already tabbed to the hull. The last holes that the foam was cut off flush I glassed with 2 layers of 1708. I had absolutely no problems with the expanding foam pushing the hull out or deck up.