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Macerator question

Maurice

Member
First, thank you to all who support this site. It has been very helpful as owner of a Morgan 384.

When we purchased R Luna Sea it had a Jabsco 18590 Macerator mounted in the wet locker, just forward of the nav table on starboard. It had not been used, although it appears to be new. I have not been able to get it to draw from the holding tank. I wondered what others are using for a macerator when asking it to lift the 5 feet or so from the holding tank. This is at the outer bounds of the spec for the Jabsco macerator's priming ability.

I will attempt a follow-up post with a photo to show the setup.

I have tested the Jabsco macerator by connecting a 53" pipe and pumping from a one gallon bucket. It failed to lift any water that high. I then connected a 24" pipe. It pumped well.

My understanding is that others are having success with this design and I would welcome feedback on types of macerators being used.

Sincerely,
Maurice Hollingsworth
 
If it is in that locker, it probably only has 3 feet of lift? At least if the tank is nearly full. It would be measured from the waste level, not the bottom of the tank. I can reach the top of the tank, so that is ~2 feet. Are the vents clogged? Is the Deck cap leaking air in? Beyond that, it is certainly possible the impeller in the pump needs servicing.
 
I originally had a manual pump in the same locker for the same purpose. I replaced with a macerator but i installed a thru hull in that locker so the pump could exit . Worked like a charm !
I really think you have a lack of prime issue.
 
If it is in that locker, it probably only has 3 feet of lift? At least if the tank is nearly full. It would be measured from the waste level, not the bottom of the tank. I can reach the top of the tank, so that is ~2 feet. Are the vents clogged? Is the Deck cap leaking air in? Beyond that, it is ceurtainly possible the impeller in the pump needs servicing.
Thank you for the ideas, Warren. I hadn't thought about the lift height relative to the fill level of the tank. You are right, of course, that if the tank is full I am well within the lifting capacity. Thanks for this point.

In reply to your other questions:
Vent line is not plugged, based on fumes when pumping the head and based on a deck-level pump-out works.
I have filled the line to deck pump out with water, so it cannot draw air.
I replaced the impeller today with a new one.

I can get it to pump overboard from a one gallon bucket, but not from the holding tank.

With the new impeller, it will blow bubbles when drawing from the holding tank, then it will slowly labor, until ultimately it blows the circuit breaker.
 
I originally had a manual pump in the same locker for the same purpose. I replaced with a macerator but i installed a thru hull in that locker so the pump could exit . Worked like a charm !
I really think you have a lack of prime issue.
Thank you, Lee. I have toyed with going to a manual pump, but would prefer the macerator. I, too, have wondered about prime. I have the thru-hull exiting in the wet locker, as you.

With the new impeller today and all lines disconnected I poured in lots of dishwashing soap and some water into the intake hose. then momentarily turned it on to draw in the mixture. I then quickly hooked it back up to the holding tank line. The result, as described to Warren, is that it blows bubbles, then labors until it blows a circuit breaker. Nothing comes out of the 1" output hose during this effort.

I have also raised the output hose and filled it with dishwashing soap and water in hopes of priming. No gain here either.

In your case are you using the Jabsco 18590 macerator? If so, does it largely empty the tank?

Thanks,
Maurice
 
Maybe the hose from the tank to the macerator is clogged? If you fill the tank to the deck plug with water, then disconnect the hose to the macerator, waste should drain out as the level is now *above* the macerator pump. If it doesn't there is a clog somewhere. I assume there is a "y" or "t" in the line to the deck pump out, and that is how the macerator is plumbed to the tank? That junction would be my suspect spot.
 
Maybe the hose from the tank to the macerator is clogged? If you fill the tank to the deck plug with water, then disconnect the hose to the macerator, waste should drain out as the level is now *above* the macerator pump. If it doesn't there is a clog somewhere. I assume there is a "y" or "t" in the line to the deck pump out, and that is how the macerator is plumbed to the tank? That junction would be my suspect spot.
A couple thoughts along this line. I had the holding tank pumped out using the deck pump-out. This suggests to me that the line from bottom of the holding tank to deck level, via a Y valve, is not clogged. I have also peered into the top of of the Jabsco Y valve with the macerator disconnected from it. It appeared clear.

The tank is now full of salt water so it "should" be easier pumping than waste.
Thanks,
Maurice
 
Morning, a gauge on the suction side of the pump would be helpful, but would also clog. When I was working in the bilge on my boat I pressureized the holding tank carefully with the exhaust of a vacuum cleaner and water in the bilge so I could locate cracks between the bilge and holding tank. I noticed I had air coming out of the side of the suction pipe. The pipe had corroded and left pin holes. A vacuum from a shore connection would overcome any small leaks in the pipe but for a small pump it might have issues. Try filling the bilge up with water to possibly cover the holes and try again. Soap and pumps do not play well together, pumps like liquid and adding soap will foam up and cause the pump to stop working. Rick
 
Also, if the pump labors and then blows a breaker, that sounds like it has prime, but there is a restriction. With no prime it should run freely without blowing a breaker. What about the output side? You are sure that line isn't clogged and the seacock is clear? There isn't something outside the hull plugging the discharge? Is it possible the pump (due to damage or age or whatever) isn't able to overcome the back pressure from water coming in?
 
Warren, looking at a past post Maurice said water could be moved from a 1 gal bucket in the bilge so the discharge must be clear. Also in my statement I said the pump will stop working with soap. I just want to clear up the statement. The pump will continue to run but because of soap the water might foam which might prevent the actual movement of water. Also some pumps have a duty cycle, they can run for a limited time before it overheats and pops the breaker. If the pump labors , I would agree with Warren it sounds like a restriction on the discharge.
 
Morning, a gauge on the suction side of the pump would be helpful, but would also clog. When I was working in the bilge on my boat I pressureized the holding tank carefully with the exhaust of a vacuum cleaner and water in the bilge so I could locate cracks between the bilge and holding tank. I noticed I had air coming out of the side of the suction pipe. The pipe had corroded and left pin holes. A vacuum from a shore connection would overcome any small leaks in the pipe but for a small pump it might have issues. Try filling the bilge up with water to possibly cover the holes and try again. Soap and pumps do not play well together, pumps like liquid and adding soap will foam up and cause the pump to stop working. Rick
Thank you, Rick, I appreciate the guidance on not using soap. I will double-check for air leakage at connections and try this strategy for hoses. I suspect the key challenge in pressurizing is "carefully", not knowing one's exact pressure level.
 
Hello Rick and Warren,

The output side may be (part of) the issue. I have opened the discharge seacock and seawater freely gushed inward. However, I did notice when pumping from the one gallon bucket directly overboard that the pump ran, then seemed to need to build to a given pressure point where it "burst" through this pressure point and then quickly emptied the bucket. Possibly this is simply overcoming the pressure of water attempting ingress into the seacock.

The seacock is somewhat below waterline - 14 inches into the wet locker. Is this OK?
 
I found that .6m spec on the same xylem site after googling the 18590.
I found your spec after revisiting the site as well. Somebody's confused...Jabsco? me?
 
I found that .6m spec on the same xylem site after googling the 18590.
I found your spec after revisiting the site as well. Somebody's confused...Jabsco? me?
Interesting!

In terms of the current challenge, I wonder if anyone from Morgan38.org has used the Jabsco18590 to pump from the holding tank in the keel? That would provide the empirical proof we need, rather than relying on a spec.

Thanks again, Dave.
 
1/2 psi head pressure is all you will see at the overboard. That should not be an issue. This is a positive displacement pump it takes a second to draw the water up from the bucket.
 
Is your thru hull clogged ? Are you sure its fully open and that barnacles have not grown up inside the hole ? A macerator can develop bad brushes over time. When removed will that macerator pump water. two buckets of water power from your truck battery !? By the way I found my keel tank leaking After failing the patching in the boat yard . I had a new tank made . Its under the port seat now macerator behind the head now. All new tank all new thru hulls, new hoses , new deck pump out . Now no line is longer than 4 feet .
The old tank was opened at the top and expanding foam poured in . I found when using green sea emergency dye in the head the bilge turned green !!
And it smelled ! I had to fix it . $$$$ 800.00 for a custom tank !!! But i have zero leaks or odor !!
 
I use the Jabsco 18590, but not from the wet locker. I also do not use a "Y" valve, but just a PVC "T" fitting, in the PVC pipe in the bilge. Hose runs from that fitting to the pump, which is mounted just forward of the kitchen sink under the aft settee bench (where my fuel filter water / separator also is) From the pump, PCV pipe runs to the head, where there is a "Y" valve before the waste seacock there.

I have slightly less lift than you, but probably only by a few inches. When testing from the pipe, the few seconds of running before the bucket emptied was the pump achieving prime. I haven't timed mine, but it runs a bit, maybe 10 seconds, before it gets prime and pumps. There is a noticeable change in sound.
 
1/2 psi head pressure is all you will see at the overboard. That should not be an issue. This is a positive displacement pump it takes a second to draw the water up from the bucket.
Thanks for this, Rick. Good to hear that this amount of pressure should be sufficient.
 
Is your thru hull clogged ? Are you sure its fully open and that barnacles have not grown up inside the hole ? A macerator can develop bad brushes over time. When removed will that macerator pump water. two buckets of water power from your truck battery !? By the way I found my keel tank leaking After failing the patching in the boat yard . I had a new tank made . Its under the port seat now macerator behind the head now. All new tank all new thru hulls, new hoses , new deck pump out . Now no line is longer than 4 feet .
The old tank was opened at the top and expanding foam poured in . I found when using green sea emergency dye in the head the bilge turned green !!
And it smelled ! I had to fix it . $$$$ 800.00 for a custom tank !!! But i have zero leaks or odor !!
I think the thru hull is in good order. The brushes on the other hand may be a consideration. Possibly a rebuild kit is in order.

I like the result of what you describe in moving the holding tank; I just don't welcome the process!
 
I use the Jabsco 18590, but not from the wet locker. I also do not use a "Y" valve, but just a PVC "T" fitting, in the PVC pipe in the bilge. Hose runs from that fitting to the pump, which is mounted just forward of the kitchen sink under the aft settee bench (where my fuel filter water / separator also is) From the pump, PCV pipe runs to the head, where there is a "Y" valve before the waste seacock there.

I have slightly less lift than you, but probably only by a few inches. When testing from the pipe, the few seconds of running before the bucket emptied was the pump achieving prime. I haven't timed mine, but it runs a bit, maybe 10 seconds, before it gets prime and pumps. There is a noticeable change in sound.
Thank you, Warren. I really appreciate the thorough details. It is helpful to understand that I am not pioneering an install that hasn't been tried by others and that a similar install works effectively. It is also very helpful to know what the end result should act and sound like as a basis for comparing my installation.

I am currently on vacation trying to solve this problem. We have spent (too) many vacation days trying to solve this one. I have decided that I will try to wait a couple of weeks to start anew in working toward a resolution. At that time I will have better access to materials and supplies. The sharing of ideas and information on this forum is most appreciated.

I will share my findings once I am back physically working on the problem.

Thanks again,

Maurice
 
I thought it might be helpful to share some of my other research on this problem. Each of the following comments are from Amazon feedback and each relate to the above conversations.

ByRob M.on December 18, 2015
A visit to the local hardware store gave me a female PVC adapter for the pump and a male for my deck fitting.
I then glued a two inch stub to the pump side fitting only to allow a friction fit to the deck fitting.
This allows me to easily mate the pump to the deck fitting.
Evacuates the 40 gallon tank in less than a minute with 5 feet of rise to the deck

ByT. Greshamon September 28, 2015
“Also, if you have trouble with blowing fuses due to resistance of the impeller turning, replace the thin paper gasket with one slightly thicker (removes pressure from the impeller): Remove existing gasket, trace with pen, cut new one with x-acto blade, optionally coat with liquid gasket during install.”

ByDuaneon February 18, 2012
It calls for a 1" ID outlet hose but I plumbed it using a 5/8" garden hose on the outlet side of pump and it seem to work ok. The only thing is the Thermo Overload will stop pump if it run from 3-5 minutes. I think it is because of the 5/8" outlet hose which is 120 feet long causing the pump to work harder.
 
I had promised to provide a summary of findings once I returned to a location with parts and finished the repair. We now have the macerator working and for future reference these were the key changes.

1) I installed a new holding tank vent on the stern. The old vent, once removed, was more plugged than I expected. This was certainly a contributor, but the original Jabsco 18590 was still reticent about priming even with the new vent.

2) I lowered the macerator by 6” as the original sat on about 9” of pipe.

3) Given the lowering of the macerator, I had to increase the height of the vented loop. This required a loop at least 23” above the cabin floor to be above water level. This height was determined using a hose connection to the through hull and playing with the height.

4) I put Super Lube onto the impeller to hopefully give it the most drawing power as I started.

5) I replaced the existing white hose with Trident Sani Shield Sanitation Hose. I felt the more rubbery texture may offer better sealing to the barbs.

Even given all of the above, the original macerator struggled to prime, so…

6) I installed a new Jabsco 18590 macerator.


With this complete, the system seems to be working fine. It primes within 4-8 seconds and pumps the holding tank dry in a few minutes. I have included a couple of photos below.

Thanks again to all who shared their expertise and experience. It was most helpful.


IMG_0035.JPG
IMG_0036.JPG
 
Yup most of use have been there. New pumps new hoses. new locations. At one point i even dumped a gallon of Vegitable oil in the tank with the hope it would act as lube, !
Im glad you found a fix .
 
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