Reply
 
Thread Tools Search this Thread Display Modes
 
Old 05-03-2005, 08:29 AM   #1
Rivet Master
 
TomW's Avatar
 
1967 26' Overlander
Huntsville , Alabama
Join Date: Dec 2003
Posts: 2,918
Images: 2
Portable Macerator Use

Last year while emptying out my Overlander in preparation for repairs, I came across a Macerator pump in a nifty carrying case. Basically, the pump is used by connecting it to the three-inch sewer outlet via the stinky slinky. The device then grinds up the solids & sends them through a garden hose into the sewer tap in the front yard. The PO was quite proud of acquiring the pump in í69, and had great plans for itís use. But he ended up never using it, and hence had no advice on itís operation.

Now skip forward a mere 38 years to a week ago last Sunday. In getting the Overlander ready for our first trip of the season, I was faced with needing to empty the black tank before the 400 mile season opener because my four & five years old boys had repeatedly helped me test the new water pump installed a couple of weeks ago. Since I knew the tank had more than just water in it, the Macerator was returned to active duty.

Hereís the question: How much stretch should there be in the stinky slinky? Since getting rid of the tankís solids requires that the liquid rush out of the tank as fast as possible, it would seem to me that the slinky should stretched as far as possible so as to hold as much as possible. But the 10 foot, 12 vdc power line on the pump will only allow so much.

The majority of threads I read on this subject were contributed to by people who had permanently mounted Macerators at the tank outlet, i.e. a low flow rate. I checked the output of the pump where it was draining into the sewer, and was impressed by the flow rate through a 5/8 inch garden hose, but Iím pretty sure it was not pumping as fast as it would have out of an open three inch hose.

Anyone have any advice or observations to share on the occasional use of a Macerator?

Thanks,
Tom
Attached Thumbnails
Click image for larger version

Name:	Macerator.jpg
Views:	98
Size:	74.0 KB
ID:	11939  
__________________

TomW is offline   Reply With Quote
Old 05-03-2005, 08:32 AM   #2
3 Rivet Member
 
FireFighter's Avatar
 
Currently Looking...
bay city , Michigan
Join Date: Aug 2003
Location: 1970 31' Sovereign
Posts: 155
Images: 9
advice

my advice is to never mix up that garden hose with your drinking water hose
__________________

__________________
FireFighter is offline   Reply With Quote
Old 05-03-2005, 09:03 AM   #3
Site Team
 
, Minnesota
Join Date: Aug 2003
Posts: 6,940
Images: 59
My guess is that it won't make any difference if you stretch out the stinky or not. In order for the tank to empty quickly, it needs to drain into a well vented container. In this case, the container (slinky) is not vented, the end is closed off by the pump. You will get an airlock.

Even if you have the pump turned on when you open the valve, the air cannot leave that much faster than the liquid would. You will get about a gallon of water quickly into the hose, then the airlock will slow the flow rate down to the 10 gpm that the pump can put out.

I think most people that use macerators have tank sprayers to help dislodge the solids that build up due to slower discharge rate.

My recommendation is, you will get slightly better initial flow with the slinky stretched out, but it won't help at the end of the process.
__________________
markdoane is offline   Reply With Quote
Old 05-03-2005, 06:21 PM   #4
Rivet Master
 
TomW's Avatar
 
1967 26' Overlander
Huntsville , Alabama
Join Date: Dec 2003
Posts: 2,918
Images: 2
Quote:
Originally Posted by markdoane
...Even if you have the pump turned on when you open the valve, the air cannot leave that much faster than the liquid would. You will get about a gallon of water quickly into the hose, ...
Excellent point Don. However...

At face value, I can't believe the pump, when running, is forming an almost hermetic seal keeping only a gallon or so of liquid from entering the hose. But I can't point to some text to substantiate my point of view.

It appears actual test data is in order.

Boyz ?!? Daddy needs to check out the the new water pump a bit more...

In the interim, I would like to hear if anyone else has additional test criteria!

Thanks Don,
Tom
TomW is offline   Reply With Quote
Old 05-03-2005, 07:38 PM   #5
Site Team
 
, Minnesota
Join Date: Aug 2003
Posts: 6,940
Images: 59
Quote:
Originally Posted by TomW
Excellent point Don. However...

At face value, I can't believe the pump, when running, is forming an almost hermetic seal keeping only a gallon or so of liquid from entering the hose. But I can't point to some text to substantiate my point of view.

Tom
Tom,

The seal won't prevent water from entering, it will just slow it down. To test this theory, put a glass over an open soda can and turn it over. You need to let the air out of the glass in order to let the liquid flow in.

In the same way, the air in the slinky has to get out of the slinky in order for liquid to flow in. Some of the air will work it's way back up the slinky, through the valve and into the tank. The rest will exit through the pump if the pump is running. Either way, the flow of liquid will be a lot slower than what you're hoping for.

I'm willing to say it won't be significantly faster than if you just hooked the macerator up directly to the tank. Using the slinky might be a little faster, but it won't get you the 'flushing' action you are looking for.

I'm willing to be proven wrong!

And I'm also interested in other opinions.
__________________
markdoane is offline   Reply With Quote
Old 05-03-2005, 08:51 PM   #6
Rivet Master
 
87MH's Avatar
 
1978 31' Sovereign
Texas Airstream Harbor , Zavalla, in the Deep East Texas Piney Woods on Lake Sam Rayburn
Join Date: Jan 2003
Posts: 2,435
Images: 292
Quote:
Originally Posted by TomW
......Anyone have any advice or observations to share on the occasional use of a Macerator?....
Tom:

For what it is worth, I do not feel as if anything is "left behind" with the use of a (relatively) low flow macerator...

I believe that the "solids" will sink, as solids are prone to do, do the "low point" of the system (the drain valve?), and the "solids" (or semi-solids) will be the first thing the macerator pumps - followed quickly by the rest of the "liquids" in the black tank (these liquids should push any residual solids to the pump), then flushed with the gray tank liquid.

I noticed in the pic that there is a water hose hooked up to the pump to pump out the grind and water - I think I would try to find a 1" or a bit larger hose for this use. At the same time, I think you would be better off minimizing the "upstream" length of the slinky. Otherwise, it looks like a great setup.

I can drain 60 gallons with mine in just a few minutes - and your pump appears to be more robust than mine is.

I use a 1 1/2" discharge hose, I believe the 1 1/2" is optimum to minimize line loss and provide a high enough velocity to move everything along.

I do not think you will have any trouble at all - just be sure that all "solids" have enough time to "liquify" prior to pumping - and, of course - make sure the "boyz" do not put anything the macerator cannot pump - if you know what I mean.
__________________

__________________
Dennis

"Suck it up, spend the bucks, do it right the first time."

WBCCI # 1113
AirForums #1737

Trailer '78 31' Sovereign

Living Large at an Airstream Park on the Largest Lake Totally Contained in Texas
Texas Airstream Harbor, Inc.
87MH is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Portable Generator Marks Generators & Solar Power 38 11-04-2017 09:36 PM
Replacing Onan for a portable generator Paul Daugherty Airstream Motorhome Forums 7 06-15-2012 09:43 AM
Non Traditional AC - Not on the roof Bryanhu Furnaces, Heaters, Fireplaces & Air Conditioning 63 03-12-2006 03:38 PM
Need advice on a portable 12V freezer Xray Refrigerators 9 03-29-2004 01:30 PM
Cleaning the portable water systems after use Silvertwinkie Fresh Water Systems 4 07-01-2003 04:46 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 12:23 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.