High Capacity Deck Wash Pumps

[Roy M]

Hi folks, I'm about to install a saltwater deck wash pump to clean the anchor, wash off bird bombs, clean fish, etc. I've done some research, installed large gauge wire cable to the pump location, installed a 25 amp breaker, have a 3/4" seacock available. I will be installing a couple hose bibbs at convenient spots. The unit will be used ONLY when the engine is operating, reducing issues associated with high electrical draw.

At the moment, my preference is for the Jabsco Dual-Max, model 31670, 12 volt. I've selected this for its use of the Flo-Jet style pumps (they bought them out), there are twin pumps, operating so as to provide redundancy if one fails, an accumulator tank (built-in), and easy to access filter strainers. The whole unit weighs about 15 pounds dry and cranks out 7.5 GPM at 15 amps max draw. There is virtually no exposed metal, it will pump a five foot head (although mine will be located just above water level), and it has automatic operation, pumping only when a faucet opens and water flows.

Does anyone have experience with this or other optional pumps, for the flow rates required? I don't want a small system for this application.

[Alan Wheeler]

Are you wanting flow rate or pressure. You won't get both. I use a Rule 3500GPH pump. Good flow rate and reasonable pressure. Centrifugal pumps require flow to maintain pressure. But then, I am punmping seawater, not fresh water. I wouldn't want to pump fresh water at that rate.
25A circuit breaker is a little on the large side. I would reduce that to at least 20A max, or less.

[delmarrey]

Since your going to be running the engine, why not just run a mag. clutch auxillery pump from the motor. Garden hose would be a lot creaper then wiring, fittings and a braker.

If you wanted more flow you can just speed up the motor. Of, course you would have to get a pump rated for the max. RPM's.

[Roy M]

Thanks for the input, folks. I've completed the installation as described. The pump works beyond expectations, blasts mud and provides the volume to remove it from the foredeck. I have the option to run the engine or not without seriously compromising the batteries. I'm quite impressed with the system, and it's far easier than installing additional gear on the engine. I will be adding additional garden hose from the pump in the future when I place a fish cleaning station aft.

I have a suggestion for testing alternate options: I will fill a five gallon jug using the hose blaster at full pressure, recording the time. Then, at the same pressure setting, shoot the stream down the dock, measuring the distance it reached. Finally, I will record the current draw measured by my Link 2000 for operating the pump while blasting at full PSI. Those of you who wish to make a similar test of your personal system can then compare apples with apples. If you wish to suggest additional parameters that would improve the value of the test, please suggest them and I'll include them in my results.

As for the need to replace the 25 amp breaker with a 20 amp breaker, I won't be doing so. There is no safety consideration, as the pump uses 15 amp fuses in each of the negative sides of the two pumps (allowing redundant operation in case of failure of one pump - Jabsco's design, not mine). It also allows other pumps to be installed in the future on that particular circuit.

[GordMay]

Higher pressure (PSI) will help you break the chemical bond between the dirt and the deck. Once the bond is broken, the extra PSI does nothing to speed up the cleaning time.
The higher the flow (GPM), however, the more surface area a pressure washer can clean.
For example, a 2000- PSI model with a 2 GPM flow rate might clean approximately 5-7 square feet per minute.
If the same unit had a 3 GPM flow rate, it might clean 8-10 square feet in the same amount of time.

[delmarrey]

Originally Posted by GordMay

Higher pressure (PSI) will help you break the chemical bond between the dirt and the deck. Once the bond is broken, the extra PSI does nothing to speed up the cleaning time.
The higher the flow (GPM), however, the more surface area a pressure washer can clean.

That's where a big hose and an adjustable nozzle come into play! Fluid dynamics