PocketShip.net

Hi all. I need to fit flotation foam in the bow compartment but unfortunately it is not available anywhere in sheet form at the moment - at least, not in the small quantity that I require.

Is liquid expanding foam a viable alternative? If you have used it please let me know how it went, and what product to look for?

Stay safe and well, and thank you.

Hi,

There are several CLC PS Forum posts from former PS builders relating to the use of expandable foam flotation. See for example: viewtopic.php?f=3&t=405&p=1204&hilit=pocketship+build+space#p1204.

There may well be other posts in CLC's regular forum about using these products too. I also know several PS builders have discussed their use of expandable foam in their blogs, complete with photos of expanding foam!

I recall John Harris mentioning that the use of expandable foam can render access to the compartment interior for inspection or repair extremely difficult - although none of us want to ever have to access the bow compartment again, so one might discount this as an issue. I know a couple builders have blogged about the lengths they went to retain access through a tube to the bow section in which the bow-eye must be installed, so failure to completely isolate this area from the liquid foam products and their chemical reaction can make subsequent bow-eye installation a challenge. (That said, at least one builder installed the bow eye before putting in foam.)

I actually bought the requisite two cans of product when I was at this stage but ultimately never used them, deciding to use foam blocks as in the manual. I'd love to send these to you if you decide to go this route, so PM me if you want to.

Stay safe and wash hands.

All the best,
Mark
"Puffin" 2018

Thanks Mark. That's useful information. I will PM you if I decide to go down the expanding foam route, although I have been advised by a boatbuilder here that it is very messy and hard to control ...

Hi Steve,

From what I've read on the subject of expandable foam, it's certainly worth reading about its use and testing a small batch before going for it on your PS build. Reading builders' blogs, I see some have made it look easy with quite professional results while others have had some "clean up" to do before proceeding. Let me know if I can help and have fun building.

All the best,
Mark

I’ve been thinking about this as well. I’ve used expandable foam insulation quite a lot in certain house renovation projects and it can be hard to control.

If you’re going to use it make sure you get low-expansion type such as for windows and doors. The “big gap” stuff really expands quickly and a little becomes a lot. Surprising. It becomes a mess if it overflows and gets on anything you don’t want it to. Definitely test it before you apply to the boat.

Also, make sure you spray it in in stages and let it expand for at least 15-20 minutes or even longer. It just keeps slowly growing. So don’t try to fill any space all at once or you will have an enormous mess.

It does seem a more efficient way to fill the flotation areas of the boat, but there is something to be said about the blocks of foam as well and being able to remove them if a repair or access is required, though how you would do that without cutting through a bulkhead I don’t know.

Maybe if the foam blocks we’re cut small enough to fit through an access port?

For what it is worth, fitting the foam blocks turned out to me an exceptionally fast process and was way less fiddly and frustrating than I had feared. If I were to build another PocketShip, I would do the blocks, rather than a pour-in foam.