The 35-1 has a very shallow bilge with a small volume sump just behind and under the mast step. Touche' has a 1500 GPH Rule bilge pump tucked tightly into a space behind the mast step. It's a tight fit.
With a large capacity pump and a small volume bilge, the issue of pump cycling is very real. That is, the pump kicks on, fills the hose and then stops. The water then drains from the hose back into the sump where it triggers the process again, and again and again. One could design a system with loops and siphon breakers, etc. and have a perfectly viable bilge pumping system without cycling. When I purchased Touche', it had an impeller style pump installed in the settee storage next to the mast. A pickup hose ran to the bottom of the bilge sump. The original hose configuration ran aft through the bilge to a discharge under the toe rail in the starboard quarter, a long run of hose. A float switch in the bilge operated the pump. I removed this pump opting for the more traditional centrifugal style bilge pump. I also increased the pumping capacity significantly. After reconfiguration, pump cycling reared its ugly head. The system was simply pumping water partway up the hose only to have it drain back into the bilge and trip the float switch again. I moved the discharge to under the toerail on the port side midships directly outboard of the pump location. I also installed a Whale flapper style check valve. This system has worked flawlessly for 14 years. There is no back flow from the hose and no pump cycling. One downside of this is the bilge water spews out onto the dock depending on the water level in the marina (fixed piers). At a marina with floating piers, it ALWAYS spews onto the dock since we dock port side to. I was aware of the conventional wisdom about not installing a check valve in a bilge line. I researched the issue and found differing opinions on the subject. The Whale flapper style check valve is very simple and reliable. I have pulled the check valve and inspected it several times. It showed no signs of pluggage and has not failed to stop back flow. Last time I pulled it, I disassembled it and coated the flapper with TefGel to deter any scale deposition, etc. Your experience may be entirely different. In retrospect, there were several advantages to the impeller style pump (and a diaphragm style pump for that matter). First, a positive displacement pump will have no back flow. Second, the pick up hose could be routed to the very bottom of Touche's sump where a pump can't fit. This would allow for the bilge to be emptied more than Touche's current system. The downside is limited pump capacity and a potentially more expensive system. Also, impeller and diaphragm pumps may not handle "junk" in the bilge as well as a centrifugal so a strainer must be considered. A strainer raises the potential for pluggage in itself. If any are considering a new bilge pump system, look at a positive displacement pump. Dennis C. Touche' 35-1 #83 Mandeville, LA On Tue, Oct 14, 2014 at 9:17 AM, Jean-Francois J Rivard via CnC-List < cnc-list@cnc-list.com> wrote: > > When I got the boat it had a Rule automatic pump that determined if > there was water by running on occasion and measuring if there is a > resistance to turn the impeller.. While it sounds smart in theory, in > practice the impeller gets gooked-up with normal bilge crap and gets hard > to turn whether the bilge is dry or not, it was very inconsistent and > could potentially run indefinitely. > > I replaced the pump with the highest capacity pump that would fit in > the tiny sump area and went with the solid state Water Witch and a manual > Johnson pump. > > The Water Witch ( > > https://www.waterwitchinc.com/new/SiteElements/Pages/SecondaryPages/Products/BilgeSwitches.html) > works flawlessly,(No float to jam, it measures electrical resistance > between plates) but the I have the same spill back problem as I have a 14 > - 15 or so feet run from the pump to the stern discharge and the pump would > not prime when I used the joker valve that came with it. Also, I did not > really want to introduce the one way valve as I have read too many horror > stories about possible obstructions keeping the pump from working > correctly. > > So in the interest of time and other more pressing priorities.. I > decided to just live with a couple cups of water in the lower sump (Mostly > comes from the stuffing box dripping when we run the engine) .. The way the > boat is designed it's like a little bucket and it keeps the rest of the > bilge dry, Since we use the boat regularly the water is not too foul and > there's no real issue with the smell. > > Eventually I'd like to add another pump, possibly this one: > http://www.drybilgesystem.com/ Another thing is to get a small wet / > dry vac and just suck it after using the boat which I'll probably get soon. > > The swtich is definitely a superior design. The pump seems to work > well, outside of a second pump I don't see away around the backwash if I'm > not willing to have some kind of one way valve.. > > Quite the conundrum this one. . > > -Francois Rivard > 1990 34+ "Take Five" > Lake Lanier, Georgia > > > > > > > > _______________________________________________ > This List is provided by the C&C Photo Album > > Email address: > CnC-List@cnc-list.com > To change your list preferences, including unsubscribing -- go bottom of > page at: > http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com > > >
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