In search of the driest bilge possible

Ralph Johnstone · Mar 3, 2023

Timm R Oday25 said:
It irrtitates me to no end to see even the smallest amount amount of water in our bilge .

What are the sources of water to your bilge ?

I feel the same way about water in the bilge and early in the game decided to put an end to any source of water to the bilge. The boat was new and #1 off the list was the shower in the head. Use the shower off the stern or go without. Secondly was the prop shaft gland. No leakage allowed. The surface of the shaft is like a mirror and by using teflon impregnated flax, leakage is eliminated. The only time the bilge sees water is when I get around to testing the bilge pump by rubber corking the two the limber holes leading to the bilge and filling the bilge with water.

I just can't see why owners of beautifully maintained or beautifully restored boats allow any amount of water in the bilge. Lift the bilge cover boards and you've got a smell. The only thing in our bilge is dust.

Rjm st.petersburg · Mar 3, 2023

My source of moisture in the bilge is air conditioning condensate. The 8k AC in the aft cabin does not cycle enough sea water to accommodate a venturi. The venturi's I have seen and heard sound like someone sucking on a straw. At least the water is quiet until the bilge pump kicks on.

Davidasailor26 · Mar 4, 2023

Rjm st.petersburg said:
My source of moisture in the bilge is air conditioning condensate. The 8k AC in the aft cabin does not cycle enough sea water to accommodate a venturi. The venturi's I have seen and heard sound like someone sucking on a straw. At least the water is quiet until the bilge pump kicks on.

You can get a separate condensate pump. Those cycle on periodically when a solid state water sensor activates in the drain line. A little noise but less than a bilge pump.

Davidasailor26 · Mar 4, 2023

Timm R Oday25 said:
I use quite a few condensate pumps at work . They are taller than the floorboards will allow .They also need a much wider area and leave at least a half inch of water on the floor

The one we have looks like this.

It’s maybe 6”x 2” x 1”. The condensate pan under the AC drains to a hose that goes to the input of the pump. That hose has an in-line water sensor to activate the pump.

dmax · Mar 4, 2023

Check out this DIY system, he's worked out some of the details, it's on my project list: Build Your Own DIY Arid Bilge or Dry Bilge System

Hello Below · Mar 4, 2023

Ralph Johnstone said:
The only thing in our bilge is dust.

Tally Ho · Mar 4, 2023

I still get some water in my bilge when it rains…haven’t found the source yet (thankfully not as rainy here as the PNW

).

I installed a Volvo shaft seal to replace my old stuffing box, and that helped a lot.

Greg

Ralph Johnstone · Mar 4, 2023

Rjm st.petersburg said:
My source of moisture in the bilge is air conditioning condensate.

Never had or seen an AC unit on a boat but I always hear the same problem that the condensate discharge goes to the bilge. I'm assuming a gravity feed from the condensate sump of the unit to the bilge

If the AC unit were high enough, is it possible to install a small 3/8" thru hull below the floor boards under the AC and allow the water to gravity drain out the thru hull ? Who knows, if you're of a religious inclination, the through hull could be above the water line for ease of installation.

Tubing could be as small as 3/8"going down the wall. Lot's of time at the drawing board to work this out but who knows, it might work.

Davidasailor26 · Mar 4, 2023

Ralph Johnstone said:
If the AC unit were high enough, is it possible to install a small 3/8" thru hull below the floor boards under the AC and allow the water to gravity drain out the thru hull ? Who knows, if you're of a religious inclination, the through hull could be above the water line for ease of installation.

Unfortunately AC units are often installed in places like under settees or other storage hatches close to the level of the cabin sole. That puts them low enough that they couldn’t drain above the waterline, and any drain below the waterline would threaten siphoning either at the dock or when heeling.

Don S/V ILLusion · Mar 4, 2023

$13 and no noise.

Benny17441 · Mar 7, 2023

Nothing wrong with having a small amount of water in the bilge, it keeps the smell from the fouled water trapped below the sole at bay.

Project_Mayhem · Mar 8, 2023

For those that aren't familiar, O'Day's are notorious for leaking as everything was sealed with silicone. I do however know exactly what @Timm R Oday25 is talking about. In the O'Day 25 there's a small part of the bilge that's probably 8" deep while the rest of it is maybe 4". This is always filled with water on my boat even after rebedding deck fittings. My first concern with most non-bilge pumps is how well can it handle all the crud floating around in there. I agree that a solid state switch/sensor would be the way to go if you want to get every last drop as most passive switches require the water to reach a certain level. On the other hand, that may save the pump from running dry as often.
However, if you have all the components on hand, it can't hurt to try it. Should you decide to swap something it will be easier since the wiring and brackets will be in place already. I'm very eager to hear how well this pump holds up as I've had the same desire for my bilge

Justin_NSA · Mar 8, 2023

Ours is so dry, I can hardly call it a bilge. If it's miniscule, I'd just put an absorbent sponge or towel on the bottom.

Peggie Hall HeadMistress · Mar 8, 2023

A dry bilge requires a bit of manual labor: A shop vac and/or a sponge and a bucket after every weekend/day on the boat. As for trapped water below the sole...create access to it so you can suck it out with a shop vac. It's also necessary to CLEAN (not just toss in some bilge cleaner and turn on the bilge pump!) the bilge with detergent and water followed by a thorough rinse ! once or twice a year. You wouldn't just toss some Dawn into a sinkful of dirty dishwater, pull the plug and expect to have a clean sink...why would you expect to get a clean bilge by doing that??? Rinsing all the dirty water out is the most important part of the job! A power washer is a great tool for that..they get into places you can't reach by hand, even with a long handle mop or brush. They aren't expensive and come in handy for a lot of jobs.

---Peggie

Peggie Hall HeadMistress · Mar 8, 2023

That COULD be condensation if the boat was so tightly covered that there was no air circulation or no dehumidifier...leading to mold and mildew. So as part of your spring recommissioning, it would be a good idea to wipe all hard surfaces, especially inside lockers, inside and behind drawers, down with bleach. Put all cushions, foulies and PFDs out on deck all day for the first sunny day...sunlight is an excellent "de-mustifier."

The fun never ends when you own a boat....

--Peggie

Rjm st.petersburg · Mar 8, 2023

Here in Florida I run the AC the entire time it's at the dock on shore power. The AC condensate drains straight into the bilge. The waterbed drain kit looks like a viable option. Definitely cheap enough to give it a try. I don't want to take all of the humidity out, that would damage the wood.

Dalliance · Mar 9, 2023

The stuffing box and melt from the ice box are the primary sources of water in my bilge. Occasionally condensation if we have hot humid weather early in the summer when the lake is still cold.
I’m obsessive about making sure the bilge is dry when I close up the boat. I empty the ice box, run the bilge pump and then remove the small amount of back-flow water with an oven baster and a sponge. If there’s any water in it when I return, the stuffing is the usual suspect.
The bilge gets scrubbed clean at least two or three times per season.