I am looking to get a macerator and looking for recommendations. One reason I am looking at a homemade is that it, to me, would be handier to have a 120 vac model than to have one wired to my batteries, located on the other side of my coach. I also expect to get a little more power from a 1/3 hp ac motor than from the 12 vdc motor.The actual total cost of the homemade would be a little cheaper, but not significantly. Storage space required would not be a factor for me.I am leaning toward the homemade model, at this point. It is claimed that it would pump waste 100 feet with about a 7-foot lift in elevation through a 3/4" hose. That is much more than I ever expect to need. Primarily, the reason for the macerator is to allow me park my motorhome backward at one of my favorite spots, with the windshield facing a river. I need to pump about 35 feet to accomplish this.

For those that use macerators, is there ever an issue of the black tank not enptying well? I always thought it was important to have plenty of water in the tank so the velocity of it going out the drain would carry the solids with it. Even with the pump, it doesn't seem to me that the velocity of the exiting waste would be anywhere near that going out an open 3" valve and solids would be left behind.

A friend has a macerator on an Airstream. It is at ground level and the inlet is large diameter. I think their Airstreams has shower and bathroom sink plumbed through the black tank to provide plenty a liquids. Not sure if that is a common practice.

A macerator is typically a poop grinder and pump all in one unit. Garbage disposal is a grinder and that is all.

Bought a Flojet Portable Macerator/pump back in 2008Use it to pump waste tanks when parked at sisters/friends placesSisters is a 75' run with a 2' incline to clean outPumps groundup waste just fine.........and will do so when 120VAC is not available

Your average garbage disposal operates via gravity...simply grinding the solids that pass thru via gravity.Unless you are thinking of something different, I don't think it will work.PS: Running a 12v circuit to the other side of the rig, isn't too hard, so why mess with DIY when you can get a unit that is designed to do the job.

Commercial macerator or homemade from garbage disposer

time2roll
Nomad
Jan 03, 2020
NRALIFR wrote:
I think at this point, it is incumbent on the naysayers to prove their claim that a garbage disposal cannot be used to pump sewage uphill.
Do what you will. Even knowing a disposer would work perfectly OK I would still get the macerator designed for the purpose.
I am not naysaying anything, just not my style.
shastagary
Explorer
Jan 03, 2020
the people that say it won't work have never seen one in action. i and others at my seasonal site have been using home made garbage disposal macerators for 5 years and they work very well.
i have 75' of 3/4" garden hose to the dump station and i dump weakly during the 7 months of the year i live there.
there are utube videos of people using and making them and one guy on utube is making and selling kits on ebay to convert garbage disposals if they did not work why would he waste his time making kits to sell? and would not every one he has sold to send negative feedback about them.
my homemade one works great and makes it a quick job dumping my tanks.
GDS-3950BH
Explorer
Jan 03, 2020
NRALIFR wrote:
Thanks. That makes five now.

I think at this point, it is incumbent on the naysayers to prove their claim that a garbage disposal cannot be used to pump sewage uphill. I’ve never used one like that, but I’ve replaced several, and played with a few enough to know that the water doesn’t just “fall” out of the disposer thanks to gravity. It’s under pressure.

Otherwise, I trust that said naysayers humility will at least allow an admission that their claims should be afforded the same credentials as they afford other interweb based claims; they don’t mean squat. Possibly even less than that.

Diddly squat.

:):)

Diddly squat, and whoopdeedoo.

Perhaps you can explain why by IPC, when your drain exits a wall the invert needs to be below the weir elevation of the trap exiting a disposer? Typical forum nonsense, and you have more BS than a cow pasture.

Done with this mental masturbation, happy new year
NRALIFR
Explorer
Jan 02, 2020
Thanks. That makes five now.

I think at this point, it is incumbent on the naysayers to prove their claim that a garbage disposal cannot be used to pump sewage uphill. I’ve never used one like that, but I’ve replaced several, and played with a few enough to know that the water doesn’t just “fall” out of the disposer thanks to gravity. It’s under pressure.

Otherwise, I trust that said naysayers humility will at least allow an admission that their claims should be afforded the same credentials as they afford other interweb based claims; they don’t mean squat. Possibly even less than that.

Diddly squat.

:):)
doughere
Explorer
Jan 02, 2020
Bought a used garbage disposal at the local "Habitat" store for $10 added about $20-30 dollars of parts have used it for years. Will pump 100 feet with about 3 ft rise (that's the most I've used).

Works perfectly.

Regards,
Doug
GDS-3950BH
Explorer
Jan 02, 2020
ScottG wrote:
How a garbage disposal works

If it can do that to an Apple, the average turd has not a chance unless maybe if you had way to much swiss cheese, then all bets are off.
ScottG
Nomad
Jan 02, 2020
How a garbage disposal works
2oldman
Explorer II
Jan 02, 2020
..
ScottG
Nomad
Jan 02, 2020
NRALIFR wrote:
Got it. It’ll never work.

Centrifugal force = bunk.

If you’d ever played with one on a bench, you’d know that they don’t suck worth a dam, but as long as the flow of liquid into the top is continuous, they sure as heck will pump.

:):)

I had a plumber tell me that he finds foods scraps on the roof of houses where he's called to clear the drain line. So they will pump pretty good!

The one thing that makes me wonder how well this would work is that a Macerator cuts and grinds where a disposal pulverizes has no sharp parts for cutting.
mikestock
Explorer
Jan 02, 2020
GDS-3950BH wrote:
NRALIFR wrote:
Must be, because with rv2go’s post I could now point to four individuals who claim that they do.

They all are lying?

There’s rv2go’s post, there was one on some RV brand forum site that I couldn’t view the pictures cuz I’m not a member, and there were at least two on the steampunk workshop site I linked to.

There were also a couple of adamant deniers on the linked site, and I liked the site owners response to one of them: “This is clearly not the website for you.”

He was probably making that Jedi hand wave motion in the air, too.

:):)

Lots of people claim lots of things, that does not mean squat.

Of coarse it will work with the disposal sitting on the ground lower than the tank, and the discharge hose level with the tank supplying it at a higher elevation. But I'm calling BS on the disposal overcoming 4' of downstream head. And that's with a 10' discharge hose let alone 100' that is claimed in your link. Centrifugal force my rear end.

A garbage disposal can't do that, even on Dagobah with Yoda putting it all together.

I am not nieve enough to expect the inlet to suck any negative pressure. My outlet is well above ground level and I don't expect the dump to ever be above the disposer outlet. In any near level situation, the inlet will be, 6 " to 10" directly below the dump outlet of the motorhome.

I have personally watched a fellow camper use the garbage disposer idea and didn't see any problems and he said he had none. At the time I was just a casual observer and not planning to purchase any macerator, myself. He was not trying to pump uphill and I can't see any situation where I would, either.

From the responses I have seen here, it looks like all the objections to the homemade thing are based on speculation. I was hoping to hear from someone who has tried both and had some real experience.

rv2go wrote:
I have been using a homemade garbage disposal setup for over 15 years while parked for months at my daughters house. I pump 75 feet thru a 3/4" hose. I am hooked up to city water so it's no problem to rinse the Black tank.
Also, what I like about my setup is that the gray water will drain as used.

Appologies to rv2go. I didn't read this post earlier.

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