From: Eric Thoman <kimeric@gocarefully.com<mailto:kimeric@gocarefully.com>> Date: November 11, 2011 1:32:04 PM EST To: "trawlers@lists.trawlering.com<mailto:trawlers@lists.trawlering.com>" <trawlers@lists.trawlering.com<mailto:trawlers@lists.trawlering.com>> Subject: Re: T&T: winterizing tips Peggy wrote: You're overlooking one minor little detail: his tank discharge fitting is on the top of the tank, with a pickup tube inside the tank to the bottom. So the pump has to run dry long enough to pull contents out of the top of the tank no matter where it's installed. Putting it at the top of the tank will shorten the distance that the pump has to pull the waste before it can push it overboard....AND because it will now be downhill to the thru-hull (it's an uphill run from the pump in its current location), it will also get an assist from gravity. Reply: Peggy, I may have misunderstood your last paragraph. I thought that you were giving generic advice to all of us about where to locate a discharge pump. I did not think that you were still answering the question about the tank with the pickup tube on the top. My bad. You described where to locate a pump and then said: " An easy mod to do on most boats." I thought most boats had tanks with the discharge tube at the bottom. But, then I have not been on "most boats." I think that I agree with you that in his case locating the pump at the top of the tank is a better idea than at the bottom of the tank where it is now. If nothing else, when working on or replacing the pump he is certain to have liquid in it. Also, if it is high and dry as you suggest there is nothing to winterize. Have fun and keep your motor running... Eric Thoman Abyssinia Well, for me it's all hypothetical and moot anyway. I'm not going to be relocating my discharge pump or otherwise rearranging the system, just cleaning and winterizing it. Last year I left it to my boat yard to do, but this year I'm taking on parts of the work myself to save $$. I think in many cases, perhaps even most cases, the physical constraints of the boat force most of the equipment location decisions. Optimizing within all the physical constraints is the challenge (and fun part for people like me). In my case, the cabin sole is directly over the holding tank, so unless I want the discharge pump in my companionway, it's not going to be above the tank. In its current location, the pump has maybe 2' of suction head, and 4' of discharge head since it needs to lift the waste up and over a vent loop. All of that is well within the specs of the pump, so I'm perfectly comfortable with the current arrangement. Also, it's a bellows-style pump (Sealand TW Discharge Pump) so the initial dry pump isn't a problem. My winterizing plan is to load up enough antifreeze in the holding tank so the pump an get suction, then pump it through the discharge system once hauled. In doing so, I'll find out how good a job I did of flushing out the system. With a pump out, there is always residual "stuff" in the tank. Adding water to clean the system dilutes it, but never completely flushes it. Hopefully I've diluted it enough to make the experience less than horrific.