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Re: Venting A Sealed Compartment - MY SOLUTION
By:Scotty
Date: 9/16/1998, 11:28 am
In Response To: Re: Venting A Sealed Compartment - MY SOLUTION (Nolan Penney)

> Why are you so resistive to a hatch on the bulkhead? You can buy them
> cheaply, or make them even cheaper. I made mine.

> Remember, the water is not going to be under much pressure trying to get
> into the compartment. Even if you torpedo the boat under a wave, it will
> not stay down long, and does not go down far. Water intrusion from
> pressure is minimal therefore.

> Foam is neat stuff, but does have its drawbacks. Namely its failure to
> actually completely fill a void, and its superb water holding abilities.
> I've opened up far to many boats to find water in a water tight void.
> That's bad enough, but with foam there holding the water against a single
> location, it sets rot off nicely. Which is also why I do not like
> inaccessable water tight compartments. Bad news, imo.

> Foam still does not address the pressure change problems that take place
> with temperature. It does a bit in that it insulates, and a bit more
> because it takes up space. But put a sealed compartment out in the sun and
> it will pressurize. Same with cold. The foam helps, but doesn't change
> physics. You will still have structural problems as a result, they'll just
> take longer to happen, and reverse.

> Be aware to that some of the foams re-cure as the temperature goes up. So
> if you build the boat on a cool day, deck it and take it out into the sun
> to bake, the foam may kick off and start expanding and recuring,
> potentially blowing your deck off. I've seen it happen before.

> A bulkead hatch is therefore good news imo. You can inspect the
> compartment, drain water, dry it out, and even store things. Personally, I
> prefer bulkhead hatches to deck hatches because of waves, but that's my
> own preference.

Advice: Penney wise, Ward foolish. Jim; Combine two technologies, the bladder in well water pressure tanks, and the self-inflating camping mattress. Install a bladder containing enough soft foam to partially expand it. Mount this via tube to hatch to allow for pressure equalization. The water that may also enter will be in a controlled space, not available to screw up the wood in your forward compartment. It can be drained by standing boat bow-up on a warm day. It can be maintained seasonally by removing the hatch. The hatch can be held by corrosion resistant fasteners which can be gripped with a six foot long sticky wrench. The mounting holes can be chamferred for easier insertion. The hatch can be gripped by a gasket with a slightly undersized I.D. to hold it in place while you fasten it with six foot sticky wrench. The hatch can be located by a tapered pin in an extra hole, outside the sealing diameter. If the length of the wrench is just right, your head will be in a position to muffle your comments while doing this seasonal task. Having solved your problem, I'm going to refill my paper tray and wait for P.J. to check in. He may still be typing, but his answer is going to be worthwhile considering. I discovered the "Guestbook, threaded" form, which prints out the whole thread, (suitable for framing) TNX, Scotty

Simple Solution: Stuff soccer ball bladder in hole. If it rolls into cockpit, it was hot. If it dissapears, it was cold. Put in another. Yearly, remove collected bladders with gaff hook.

Messages In This Thread

Venting A Sealed Compartment
Jim Ward -- 9/15/1998, 4:16 pm
Everyone wants to vent
Paul Jacobson -- 9/18/1998, 4:19 am
Re: Everyone wants to vent
Rick VanBuren -- 9/18/1998, 4:38 pm
vent and w(h)ine
Paul Jacobson -- 9/19/1998, 9:26 pm
Re: Everyone wants to vent
Mike Spence -- 9/18/1998, 3:14 pm
Re: Venting - it's not a problem
Jay Babina -- 9/17/1998, 10:06 am
Re: Venting A Sealed Compartment
Pat Pavlik -- 9/16/1998, 10:56 pm
Re: Venting A Sealed Compartment
Mark Kanzler -- 9/16/1998, 4:02 pm
Re: Venting A Sealed Compartment
Jon K. -- 9/15/1998, 7:40 pm
Re: Venting A Sealed Compartment - MY SOLUTION
Jim Ward -- 9/15/1998, 8:59 pm
Re: Venting A Sealed Compartment - MY SOLUTION
Mark Kanzler -- 9/16/1998, 11:35 am
Re: Venting A Sealed Compartment - MY SOLUTION
Nolan Penney -- 9/16/1998, 8:45 am
Re: Venting A Sealed Compartment - MY SOLUTION
Scotty -- 9/16/1998, 11:28 am
Comments on Your Solution
Jon K. -- 9/15/1998, 10:49 pm
Re: No Foam. Inspection Port In Bulkhead
Jim Ward -- 9/16/1998, 10:28 pm
Re: No Foam. Inspection Port In Bulkhead
Mark Kanzler -- 9/18/1998, 5:35 pm
Re: No Foam. Inspection Port In Bulkhead
Mark Kanzler -- 9/18/1998, 5:55 pm
Re: No Foam. Inspection Port In Bulkhead
Nick Schade -- 9/17/1998, 5:01 pm
Re: PVC pipe fittings
Nolan Penney -- 9/17/1998, 8:01 am
Re: No Foam. Inspection Port In Bulkhead
Mike Spence -- 9/17/1998, 12:50 pm
Re: No Foam. Inspection Port In Bulkhead
Rick VanBuren -- 9/17/1998, 4:17 pm
Re: No Foam. Inspection Port In Bulkhead
Pat Pavlik -- 9/16/1998, 11:56 pm
Flexible inspection plate
Mike Spence -- 9/17/1998, 12:17 pm
Re: Venting A Sealed Compartment
L.C. -- 9/15/1998, 7:26 pm
Re: Venting A Sealed Compartment
Mark Kanzler -- 9/15/1998, 5:46 pm
Re: Venting A Sealed Compartment
Mark Carroll -- 9/15/1998, 4:46 pm
Re: Venting A Sealed Compartment
Jim Ward -- 9/15/1998, 5:23 pm
Re: Venting A Sealed Compartment
Ross Leidy -- 9/15/1998, 4:34 pm
Re: Venting A Sealed Compartment
Martin Foil -- 9/16/1998, 3:10 pm
run a vent tube
Brian C. -- 9/15/1998, 5:30 pm
Re: run a vent tube
Jim Ward -- 9/15/1998, 6:19 pm
Re: run a vent tube
Rick C. -- 9/17/1998, 10:15 pm
Re: run a vent tube
Mark Kanzler -- 9/18/1998, 6:42 pm
Re: Gas mask valve
Mike Spence -- 9/18/1998, 3:01 am
Re: Gas mask valve
Mark Kanzler -- 9/18/1998, 6:55 pm
Re: Gas mask valve
Nolan Penney -- 9/18/1998, 7:01 am
Re: Gas mask valve
Mark Kanzler -- 9/18/1998, 7:03 pm
Re: Tandem valve....
Tor-Henrik Furmyr -- 9/19/1998, 6:42 pm
Re: Tandem valve....
Mark Kanzler -- 9/20/1998, 1:06 am
valveless `valve'
Paul Jacobson -- 9/19/1998, 8:44 pm
Re: Gas mask valve
Rick C. -- 9/18/1998, 2:28 pm
Re: Venting A Sealed Compartment
Jim Ward -- 9/15/1998, 5:28 pm
Re: Idea #2
Nick Schade -- 9/16/1998, 5:57 pm
Re: Venting A Sealed Compartment
Nick Schade -- 9/16/1998, 5:44 pm
Re: Venting A Sealed Compartment
Ross Leidy -- 9/15/1998, 5:52 pm