Isolating Engine Compartment from the Bilge

[scenarioL113]

I want to glass in the area that allows water to run from under the engine area to the bilge. Right now there are a few access holes that allow water or fluids to pass thru the stringers and beds. On my B28 there is 3 area from the keel to the outer beam on each side that can collect water that will sometimes go through the hatches. The boat is a 1971 and I dont know if the engine beds are original or not but I dont think they are. They are in decent shape and do not plan to replace them.

I have had the boat for 20 years now and repowered 10 year ago to diesel.
I know in a perfect world the diesels would never leak a drop of oil or fuel but...you know...

My intention is to glass off these holes that allow the water to drain to the bilge OR to maybe just glass in a separate rectangle of some kind of material on the hull to form a "dike" around the engine that would allow any oil that may drop from the front or rear main seal and I guess the trans as well to be kept from draining to the bilge. Like maybe 2 or 3 inches in height.

Whether this is required or not I would like to do this but I would like to hear from some of you with any suggestions you may have.

Also, I think that Capt Pat (or maybe someone else) years ago mentioned to run a PVC or some kind of tube or pipe thru the holes b4 you glass them closed that has a removeable cap that you could use to drain the area if water got trapped in there...anyway Thanks

I am not sure how to handle this so any input would be greatly appreciated.

Frank V

[Tony Meola]

I remember that post also[.

I think it would be pretty easy to do. I would put a couple of layers of glass matt over the opening, then after it set up drill a hole for the pipe. Then slide the tube in and glass it in.

As I think about it you would probably need to put an elbow on the capped end so you can pump or suck out the water. Otherwise I think the tube would be laying on the hull and you would have issues getting the cap on and off.

[Yannis]

Im seriously considering this too.

Water is coming from 5 different openings into the under cabin bilge, one at the keel level and two on each side right above each stringer. Also you have to see how not to create hard points between the main bulkhead and the hull, in a few words this is a difficult task, as there really is no space to work with glass in the space under the engines.

Ill attempt to do this in the winter when Ill probably pull the motors for some tlc after 14 years that they've been sitting in there.
In my boat all hoses pass through those openings so I will have to see how to move these hoses up and through which new holes...
This is the most annoying thing in the 28, I hope to finally be able to solve this soon. If you do this before me be sure to post pics!

[Marshall Mahoney]

I did it many years ago when I had Detroit 453's (you can hang a picture of a 453 on the wall and it will leak oil...). The obvious secret is to get the area clean -- sand paper, acetone, lots of scrubbing in tight spaces with the engine in the way. I just used 3 layers of matt (angel hair). I did not put a drain tube, but that would be a good idea. I use a 5 gal bucket shop vac to get rid of water/oil accumulation. I fiber glassed a raised lip on the deck under the engine boxes to keep rain/wash down water out. Never had an issue with an oily bilge since.

[Yannis]

Marshal,

Your metaphor with the 453’s poster had me really laughing.

I’m not sure what you mean by the glassed lip, it seems that whatever one does there will always be water in the under the deck plus engine bilge. The point is to stop that water from entering the cabin bilge.
There are 5 entry points, at least two of which require some thought as the drain hole of the stringer ( I think the top one), that crosses the bulkhead, meets with the hole on the bulkhead. I should think that while one tries to block water from aft to fwd on the bulkhead they should not block the stringer drain, as in the opposite case there would be water blocked over the upper stringer, Im thinking when you wash the cabin in the winter, any fresh water drips, shower or galley water on the port stringer etc.
The keel hole is the easiest, Cpt. Pat provides a possible solution with a round plastic hatch, I’ve done it with a drain hole, but at least in that area you have some workspace. In the other four, you either need an educated monkey or you spend some serious cash in physiotherapy. And like you said, although I don't have one drop of oil, still there will be tough corners where the glassing will not stick because of a greasy hull etc, thats why I’m saying that this job has to be done when the engines are pulled.
One reason I want to pull the engines is this one.

[Marshall Mahoney]

My goal was to prevent oil from the engine bilge from draining (thru the drain slots under the engine mount stringers) into the main bilge. I glassed closed these slots. The "lip" was added along the edge of the deck that extends under the engine hatch. This prevents water from flowing under the engine hatch and filling up the engine bilge -- which cant drain since I glassed it in.

I was not concerned with main bilge water flowing to and from the cabin -- since it is now oil free...

[JH_B28]

On my 28 I sealed the limber holes in the areas where the engine beds are and also where the stringer meets the main bulkhead. This seals off and makes a compartment below the engines in case of oil leaks of some sort. In the future I plan on putting garboard drain plugs where I sealed the limber holes so I can drain the water easier when its time to clean the engines.

Since the 28's keel is deeper at the bow, all the water always flows forward. The best you can do is seal the main bulkead (below the door) at the keel so you can have a dry interior bilge always, considering you have a sump pump for the shower & A/C condensate. Now all the water from the cockpit area will stay in the center area between the engines and be pumped out from there. For us fishing guys down here, we also seal the bulkead aft of the engines where the fuel tank is, so any saltwater from backing down stays in the aft bilge. This way you have three compartments and a "dry" engine compartment area which is very nice to have.


Regards,

[Yannis]

Jorge, hi,

There is no way the cabin bilge can stay dry by just sealing the keel opening alone.
Water finds its way over the stringers, flows forward, and finds its way lower into the cabin bilge through the stringer openings.
Also, the water that drips down from the motor hatches’ rim is mostly going forward onto the stringers, without even bothering to settle into the bilge between the engines.
Unless my boat is different from other 28’s, that is.

[JH_B28]

Jorge, hi,

There is no way the cabin bilge can stay dry by just sealing the keel opening alone.
Water finds its way over the stringers, flows forward, and finds its way lower into the cabin bilge through the stringer openings.
Also, the water that drips down from the motor hatches’ rim is mostly going forward onto the stringers, without even bothering to settle into the bilge between the engines.
Unless my boat is different from other 28’s, that is.

Hi Yannis,

You are correct. That is why I also sealed the openings you mention where the stringers meet the bulkhead so that the water cannot get into the cabin bilge. Also, I plumbed all my hatch drains to drain directly overboard using 1/2" pvc piping so technically there will be less water in the bilge overall. I can show you photos when I finish.

[Yannis]

Jorge,

I think you have a single motor hatch(?) ...however the blocking of the water above the stringers at the bulkhead level gives me a lot of hope! I have to make sure while doing this, not to block the downward water path of the stringer inside the cabin.
If I ever manage to make a dry cabin bilge, my storage real estate will skyrocket.
I’d love to see how you plan to send the drain water above the hatches overboard!