Need advise in building bulkheads and foaming correctly

[kedd]

I need to put in the blukheads and foam outboard of my stringers.

Should I have drainage in every bulkhead even though the will be foamed, so water can escape?
I want to make sure I do it right the first time!!


Your thoughts please!

Thanks in advance
Kedd

Here are are a couple of pics
That bulkhead is not glassed just an example

[gran398]

Kedd,

Your question is one that was answered by the boat-builder, got lucky, didn't have to ask....over the course of discussion/planning, he just went through the steps.

You want "weep holes" through every horizontal bulkhead installed, at the lowest point in the bilge where it rests. That is, the lowest area in that section of the bilge. Per your illustration, the weep hole would be at the base beside the outboard stringer.

And go ahead and make it big enough so the water flows without getting shut down with pine straw, leaves, bilge crap, etc...thinking a one inch hole (or a bit larger).

Seabob can give good thinking on hole size, flow, etc.

[kedd]

Gran398,

Thanks.
That makes sense, but what about the foam?
Wont the foam just block everything and fill the holes when I pour it?


Kedd

[LilRichard]

Line the holes with PVC tubes...

[Capt. Bob]

Gran398,
but what about the foam?
Wont the foam just block everything and fill the holes when I pour it?
Kedd

A logical thinker, I like that.

You need to only move water from where it can get trapped, to the stern for removal.
Logic would dictate that a compartment fully filled with high density foam cannot hold water so no need to drain. That is if you fill every nook and cranny.
If you have areas that are "upstream" of said compartment that could hold water then you need to convey it to the stern bilge. I would think that a pipe (pvc) would be your best bet. That will allow the water to pass through your foam fill compartments. Makes more sense than a weep hole filled with foam. The weep hole is now filled with a hollow conveyance device aka a pvc pipe.

Just a guess.

Edit:
Two wheel guys think alike.

[gran398]

Line the holes with PVC tubes...

Yes, if you are pouring foam, exactly. You will want longitudinal pipe, or some type of blocking method, running full length.

My guy is not pouring foam....simply laying in closed cell foam blocks for flotation. Floats above and is pinned beneath the deck in an emergency. Therefore no need for pipe.

However, under the tank, is using 2" PVC pipe, split lengthwise like bamboo to form a trough.

[kedd]

Ok, I totaly get the PVC pipe but the foam will still fill it.
This ok I guess if I'm only letting moisture escape all the way to the stern.
In theory it will just drain through the foam filled pipe instead of hitting a solid wall?

Kedd

[gran398]

There won't be any foam inside the pipe.

But taking it a step further, since you'll be pouring the foam:

Go with that same idea of the 2'' pipe split down the middle. Lay it in so that the "dome" faces to the top, as guard for the long drain. Then pour the foam on top. That way, there is NOTHING between the bottom of the bilge and the pipe.

I wish I could draw....

[kedd]

Gran398

No need to draw, thanks makes total sense.

Kedd

[gran398]

Good deal, 'cause I'm computer challenged  

Think that should work fine....keep us posted!

Thanks.

[Capt. Bob]

Split the pipe?
Must be an awful tight budget.

Why would you do that? Besides, the cut has to be perfect as well as the finish on the hull bottom to insure a good seal but then you can always "glue" it down with 5200.

Let's see:
Labor to cut the pipe, sand the hull surface and slap down glue. $$$$
Drop in a section of full pipe, add foam where you want and let the four winds blow.

Think K.I.S.S.

[gran398]

Sure you could put a piece of tube in. Then the water flow is restricted due to the circular nature of the tube. The water basically has to flow uphill into the tube. Then underneath the tube will hold water too.

You can take the two inch pipe, and rip it on a table saw with a fine blade. Takes about thirty seconds. Then you have two pieces for the price of one.

Bear in mind that this is what a boatbuilder has done for 35 years. I'm not taking credit for the idea.

And no need for glue. And no need for a tight seal. This is basically a guard to protect the channel from the foam. Just tack it down here and there initially, the poured foam in the end will hold it in place.

[wingtime]

I think the split pipe glassed to the floor would flow the best.  Great friggin idea.

[MarshMarlowe196]

You know... the split pipe bonded to the floor is really not a bad idea.  I've seen it done by other builders myself.  

As far as it being more labor intensive and costly, yes it will be, but not by much in the big picture of rebuilding a boat, and of course buying only half the length of pipe needed will offset this cost     And really, if were just talking draining bulkheads only from forward to aft, it's not much half-pipe to bond.  

With just a round pipe laying on the inboard, there will always be a marginal amount of standing water that wont make it through the pipe, simply because the inboard of the keel is forming a "V", and the pipe is well, round (like Gran stated). Whether or not this would cause a problem... it could, but... probably not. If we're talking better drainage, half-pipe wins.



 

[slvrlng]

This is what shine is doing on his Seacraft. Wow split pipe. I just need to find my pipe splitter now!
Just scroll down and you can see how he tabbed the pipe in. Will never move again!

http://forums.bateau2.com/viewtopic.php ... 7&start=40