Pouring my first bilge...advice? steps again?

[Helmar]

You might have a few little voids right next to the stringers but with the amount of flotation you will gain, its not much of a loss.

We like to put a couple of ABS 1/2 pipes up through the cabin bulkhead and run then to the rear bilge as so if any water gets in the cabin, it can run back to the bilge and get pumped out.

If you decide to do it like the pictures above, save the hole plugs you cut out, tap down the foam as so you can put them back in, glass them in, then the sweet part is to glass mat the whole floor right up to the hull sides as well as the cabin bulkhead back to the bilge area.
Any rain water that gets in the boat will be forced back to the bilge.
Even if the cabin windows get left open and rain gets in, that would also go to the rear bilge.

Joes 2 cents

[Scott McDade]

Okay, sounds like I'm going to get a little foaming practice. Any advice on which brand to buy, and where to get it?

[Marty Loken (Norseboater)]

Foaming

Scott -

The main reason to lay the floor first and get nearly-full chambers of foam is simple: Structural rigidity. The foam may be easy to shave with a rasp but it's incredibly dense and hard to compress across a broad surface...so you absolutely want foam pressing up against the underside of your floor. The holes, of course, allow expanding foam to overflow harmlessly during its rapid-expansion process, so don't do anything to block the expansion. (The only times I've gotten in trouble--with sections of lifting floor as a result--were when I blocked the pouring hole in an attempt for force the expanding foam deeper into underfloor recesses. The result, instead, was that the foam laughed and said, in effect--You Can't Stop Me, Norwegian!...and the whole floor started to rise.)

You'll want to start with conservative amounts of the mixture, and work your way up to larger batches, learning along the way how much volume results from each mix. I never mix more than 20 ounces at a time--10 ounces of Parts A and B--because you can't thoroughly stir together much more than that before the stuff starts to "go off."

Anyhow, back to structural rigidity. With a floor cavity that is filled solid, you'll be amazed at how much quieter your hull is when running at speed, and the wall-to-wall, bottom-to-floor foam will provide amazing strength to the bottom of your boat. If you only poured loose puddles of foam, that only touched the underside of the floor here and there, you'd end up with far less hull rigidity and maybe even particular spots in the floor that 'bounced' with hull compression. Fill 'er up and you'll be a lot happier in the end...but use the PVC drain-tube feature that Joe mentioned. We do that in all of them, so that any water that might be trapped in the forward cabin area can drain harmlessly through the foam and back to the stern bilge pump. (Of course, you'll need to box in a non-foamed sump area at the transom, maybe about 12" x 12," where the PVC pipes emerge and you plant the bilge pump.)

Give me a buzz if you have any questions...

- Marty