Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 16-01-2006, 21:41   #31
Kai Nui
Guest

Posts: n/a
HMMMM? I think I'll stick with the old swipe pump and swish
It is surprising how complex a waste system can get. While designing the system on my tri, I shopped for quality rather than price, unlike my other installations. While it seems a minor point, a good functioning head that does not clog, or loose suction when drawing in water is a big comfort when everything else is going wrong on the boat. I am also considering adding a MSD to my system at some point, but I want to add it in line with the holding tank with a valve, so I can comply with the zero discharge if needed, but can discharge treated waste when appropriate. Has anyone set up this design before? is it problematic? My main concerns are the run cycle for the MSD, and the ability of the MSD to draw waste in from the tank. So far, the local chandlery and West Marine have not been able to answer these questions.
__________________

__________________
  Reply With Quote
Old 17-01-2006, 19:50   #32
Registered User

Join Date: Oct 2005
Posts: 341
Send a message via Skype™ to gosstyla
Kai Nui,
ever consider a compost head?
__________________

__________________
gosstyla is offline   Reply With Quote
Old 17-01-2006, 20:06   #33
Kai Nui
Guest

Posts: n/a
YES! I have used them, and researched them extensively. Two problems have prevented me from going this route. One, is the size of the unit. i have not found one that would fit the space I want to use, and the other is the power draw. It is not much, and if it was the only concern, I think a solar vent could be installed to handle it, but the size of the units is the big issue. Also, it is one more thing to deal with disposing of the compost. It is a bit different on land where you can just throw it in a compost pile, but on a boat, you are throwing solids over board, and in a harbor, you need to find other means of disposal. The free pump out is easier. I still think they are a good way to go, and would not turn away from the idea if a unit was designed that fit my boat.
__________________
  Reply With Quote
Old 18-01-2006, 08:47   #34
Registered User

Join Date: Oct 2005
Posts: 341
Send a message via Skype™ to gosstyla
I had the same problem - couldn't find one small enough to fit.
__________________
gosstyla is offline   Reply With Quote
Old 18-01-2006, 19:50   #35
Kai Nui
Guest

Posts: n/a
I considered trying to build a system into the holding tank, but it requires too much water to clear the bowl. I would also question if a composting system would work with salt water. It realy is a shame, because this is an excelent system. for a cabin it works very well, especially in an area that does not perk well. This system with a gray water system will work full time, but, on a boat, it is just too problematic.
__________________
  Reply With Quote
Old 18-01-2006, 20:09   #36
Registered User
 
Jim H's Avatar

Join Date: Aug 2005
Location: London, UK
Boat: '67 Cal 20, Aurora and "73 Rival 34, Southern Rival
Posts: 162
Images: 7
Type II MSD

A boat we're considering has a Type II Mansfield TDX that appears to work fine and does a direct discharge.

I've been reading about similar Type II MSDs at http://www.boatus.org/onlinecourse/R...ect/info4c.htm

Two things that surprise me-- it's in a relatively small boat with only two batteries. Second, the online information suggests a typical install is $4,000. Geez... Not having to do pump-outs is attactive, however.
__________________
Jim H is offline   Reply With Quote
Old 18-01-2006, 20:21   #37
Kai Nui
Guest

Posts: n/a
A typical install? I guess that is subjective. The cost of the unit is about $1000 to $1500. To add it to my system would require an additional y-valve, the unit, some hose, an additional breaker, and some wire. If you combine the total cost of all the components I have listed, you would be close to that $4000 mark, especially if you are paying someone else to do it. FWIW, I have seen the MSD's on EBay for around $250 used and working. What I am not sure about, is, as I asked earlier, if the MSD can be installed in series with the holding tank, or if it needs to be in parralell. If it can be installed in series, it would be an even cheaper install.
__________________
  Reply With Quote
Old 18-01-2006, 23:32   #38
Registered User
 
NoTies's Avatar

Join Date: Nov 2005
Location: Vanuatu
Boat: Whiting 29' extended "Nightcap"
Posts: 1,378
Images: 2
OK, got to confess to knowing nothing about composting toilets but I've had some experience with both activated sludge & fixed bed aeration sytems using salt water. Both systems use bacteria as the secondary treatment (maceration is primary treatment). These systems work fine in salt water and will often work better than with fresh water if the fresh water is chlorinated. The only problem is changing from fresh to salt & back as the bacteria involved for each system takes some time adjust. An important thing to bear in mind is that secondary treatment systems do not generally remove faecal choliforms from the waste but treat the effluent to such a stage that UV sterilisation or chlorination will kill the bugs. I.E. the effluent will be clear but will still contain pathogens.
They used to call me the "sceptic avenger" down here.
__________________
Pete

Positively, socially deviant.
NoTies is offline   Reply With Quote
Old 18-01-2006, 23:51   #39
Kai Nui
Guest

Posts: n/a
Chemistry and micro biology are not my strong points, but i know septic systems (long story). I know you are correct that certain bacteria can thrive in salt water, however, the composting toilets rely more less on bacteria, and more on evaporation, so i do not think it would be a major issue. I do think evaporation rates of salt water might be a problem. And the remaining brine mey effect the composting process.
So how do you dig a latrene in perma-frost?
__________________
  Reply With Quote
Old 19-01-2006, 00:02   #40
Registered User
 
NoTies's Avatar

Join Date: Nov 2005
Location: Vanuatu
Boat: Whiting 29' extended "Nightcap"
Posts: 1,378
Images: 2
"So how do you dig a latrene in perma-frost?"
You don't, you get the GAs to do it.
I understand abit more about the composting toilet now, might do a bit of research.
Cheers
__________________
Pete

Positively, socially deviant.
NoTies is offline   Reply With Quote
Old 19-01-2006, 00:10   #41
Kai Nui
Guest

Posts: n/a
__________________
  Reply With Quote
Old 19-01-2006, 11:21   #42
Registered User

Join Date: Oct 2005
Posts: 341
Send a message via Skype™ to gosstyla
pwederell you may want to check

http://www.sun-mar.com

They have, or at least did have, some good general information about compost heads.
__________________

__________________
gosstyla is offline   Reply With Quote
Reply

Tags
marine head

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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
Nigel Caulder on Hoses GordMay Construction, Maintenance & Refit 19 30-06-2015 13:14
Marine Diesel Links GordMay Engines and Propulsion Systems 3 13-06-2008 13:58
West Marine Sto-Away Seat? exposure General Sailing Forum 4 20-05-2004 21:07
Marine News GordMay The Library 0 20-05-2004 02:57



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 17:37.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.