Floation, foam, or,

We are making frames for the boat!

Will start on the building gig next week!

There will be three compartments that have no access.

They are sealed by bulkheads!

Do they need to be vented? I would hate to
bust something from heat expansion?

The front two feet and the sides of the cockpit.

They are 40"X10"x24" and (2) 16"X12"x120".

Can I just fill them with lose foam blocks, scrap
as in, old computer packing and such? Peanuts?
Or does it need to be secured? In trash bags?

If I can use the blocks, they need to be put in before
the deck beams and battens are in place!

The boat is 16'X6'X16" and should weigh between 3 and 4
hundred pounds!

We decided on a 16' scow with a 5/8s sloop rig and a
ballasted dagger board! No provision for motor, oarlocks!
Everyone involved is happy with this one!

 

Unless you enjoy rot, mold, mildew, etc. then place some vents in those confined spaces. If they're serving as floatation chambers, then use some 6" or 8" deck plates. They make several types: smooth face/screw on, textured face/screw on and of course the pry-out models (which I hate). They're available in metal if you want bulletproof too.

Open them up each (and every) time you store the boat, so the compartments can get fresh air. The deck plates will also permit them to be used for light storage too.

 

Thank you for your rely.

The front compartment is unreachable once the boat is
decked. The plates would need to be in the fore deck and
I don't like that idea. I think a length of dryer vent hose
will solve the problem. It is above the water line. The sides
will be full of foam so they can be vented all the time.

Is it ok to just throw the foam pieces in? We may throw
a few 2 liter bottles in as well! They are cheap!

 

If this is a wooden boat (any construction method) then you better vent all the spaces or you'll regret it in time.

Deck plates are water tight when closed.

 

PAR's advice is good. Actually you can use anything for flotation that will accomplish the job, plastic bottles, ping pong balls, foam. However if you are going to use air chambers, then the chambers should be sealed. What I did on my boat was go to the local Home Depot, and I bought two boards of polystyrene insulation. 2" by 2' by 8'. That's about 2 2/3 cubic feet which will support about 160 lb. The stuff is cheap. BUT, if it's going to be exposed to gasoline or other solvents it's no good. They will dissolve styrene. You can get polyurethane foam in sheets from building supply companies. It doesn't dissolve but is more expensive.