keel voids

[bill@ariel231]

I'm doing this from memory, someone with a tapemeasure and a boat nearby needs to double check the dimensions...

the void aft of the ballast is roughly 40" long, 8" athwartships and approx 24" from the bottom of the keel to the bilge.

in cubic feet... 3.25x0.75x2.0 = 4.875cu

at 7.481 gal/cu that's 36.47 gallons ...or... approx 290lbs of water.

when I opened the keel during the original demolition, the foam was 100% saturated. With the bottom of the keel cut away, it took a full year to dry out.

In the succeeding years, I've occasionally drilled the cavity with a 1/4 inch bit to check that it is still dry.

[ebb]

bill,
Here's one place photos would help.
In 338 the ballast keel extends from the main cabin bulkhead to the sump under the companionway. (Ebbs gallery page 12, 167 and 170) The whole bottom of the 'water tank' in 338 is the top of the ballast. With the original 'encapsulating' matt over the lead.

With the cabin sole in place (also page 12) there is a long wedge shaped volume (it's a 32 gallon tank as made). Is this where your foam is?
On 338 the whole bottom interior of the hull was left empty. From the companionway bulkhead aft there is space that narrows considerably toward the rudder. All of this is directly under the cockpit. Don't believe there should be any ballast or weight carried here. There might be foam put here to fill in the narrow crevice.

The problem with urethane foam is that it is not really closed cell and water will get in eventually. Might have a drain hole into the bottom of the foam aft of the sump so that it will remain drier at the bottom.

We have had discussion here of foam added to this space under the cockpit.
In fact Everett admitted to this dastardly deed. But this is not the water in the encapsulated ballast keel problem where the lead is.

[mbd]

Just as I was resizing a couple of my survey pics, Ebb piped in. This is what I've been calling a "keel void".

[mbd]

...and the bilge/sump. Please correct me if I'm wrong.

[Bill]

Looks like the correct nomenclature for the photos . . . although voids in the keel are also found elsewhere. A few hours searching the subject should turn up all the locations discovered by various owners.

[ebb]

Somebody else should pipe in here.
I would call that the sump,
but on 338 'they' sloped that skinny area there, in the photo, up some so that water would stay more or less right at the end of the lead ballast. So that 338's sump. It's narrow but has a bottom - how far down to the actual bottom of the keel I don't know, but it's close. It's probably a good idea to have access to the bilge pump just behind the c'way ladder.

Pg 12 (Ebb's Gal.) #169, the right hand photo shows the under cockpit view of this sump area.
The small bulkhead is built against the end of the lead ballast.
The cockpit drains and thruhulls have been removed, so you can't reference with them.

[bill@ariel231]

Interesting. The bilge on 414 appears to be deeper aft than a231 by about a foot aft. The low point in A231's bilge is directly under the companionway steps.

ebb, I see the 32 gallon water tank you are talking about (nice job there by the way). The foam filled void on mine is the region beneath the aft portion of your water tank.

Judging from the photos in 414. It would be interesting to drill a hole at the bottom of the chalked circle and see how much water runs out. The foam filled keel void i'm talking about is a trapazoidal volume shown in yellow below:

ps. For A-231, I'm in the process of adding an inspection port below the engine that will allow me to check the false keel volume annually without drilling a hole in the keel.

From what I've seen in other threads, there appears to be a lot of variability in the construction of this area from boat to boat.

[mbd]

Neat and useful picture Bill. I was thinking that's what you were talking about with the "keel void".

Judging from the photos in 414. It would be interesting to drill a hole at the bottom of the chalked circle and see how much water runs out.

I'll try and remember to measure and post when I get around to doing it.

Another good point about having the bilge pump more accessible. It's a real pian now. I have to dangle upside down through the cockpit hatch and yank it up by the hose now.

[ebb]

That must be Everette's Folly, or a DFO's.
Thanks for the great graffics!

The sump in 338 is right at the end of the ballast in your pic. Untill I walled it off you could see and touch the lead. Golly!
So that's pretty low down.
So it gets kind of narrow. (The sump hole has also been epoxy reinforced which decreases volume a bit.) You could fit in the bottom a small electric pump with no room for a float switch. So 338's electric pump cannot be a submersible.

Filling in with foam under the cockpit, as you show, would leave very little room for real bilge water.

But it looks like you could fairly easily excavate a suitable cavity in the foam and line it for an automatic bilge pump.

[eric (deceased)]

how do you know the area being injected was dry? what I used was seagoing epoxy-I filled calking gun tubes--dont recall how much was used....but water kept coming out to no end----I have found that on all full keel fiberglass boats---the area just fore of the rudder shoe----no matter what type of boat---always had crazing----with water seeping out for weeks---- jus'go to any long term haul out yard---this particular area is subjected to all the turning forces---its bound to be a vulneral place on any size boat.thats why I replaced the wrist pins with bronze bolts---not only on the shoe but on the goudgeouns and pintles.one good way to be sure the area is dry is to leave the boat in the desert for a few weeks or months.I remember the mojave desert to be very arid in deed---and the heat----

[ebb]

You can't know can you?
And if anybody can think of a way to dry in there wihout mortifying the boat I'd like to know too.
338's hull had every opportunity to dry out -and then I drilled the drains - and it sat around some more. You try to imagine what floor sweepings and pieces of balsa Pearson put down there when they placed the lead and after four decades of soaking in weird bilge cocktails what kind of pudding it all became.

The reasoning was to replace the void with something and lock the ballast up. Shouldn't really have a loose long ton of lead in the bottom of yer boat. I have a feeling that most laminating epoxies are not unhappy with damp. It should flow fairly well into all empty space and setup as well. But using epoxy in there increases the chance that it is really encapsulated and maybe that helps keep water out of the laminate.

And I feel better knowing (assuming) the boat in the yard is sitting on something hard.

Probably could force hot air thru the void/ballast with extra holes in the hull drilled in the 'corners' of the ballast cavity. Maybe a commercial dehumidifier could be used. You then may get a better afinity to the surfaces and junk on the inside of the hull if it was drier - but I don't think anything is going to actually bond together really.

[eric (deceased)]

or any other desert will dry it out but good.another possible way would be to chase the water out with acetone