Composting head substrate when abroad

[svspirited]

The time has come to ditch the forward head and holding tank and replace with something new, I need the space from the holding tank and I'm sick and tired of repairing marine heads. We have a second head aft with no holding tank than we intend to use mainly for numero uno or numero dos while at sea but for anchorages, no-discharge zones, and crowded low flow anchorages I want something else.



After doing a bunch of reading here and elsewhere I'm just about sold on a composting head. However, it seems most of what I read involves liveaboards based in or around places where Amazon will deliver making refilling of the head substrate easy enough. My question involves how easy it is to get the material to fill the bed with while abroad, seriously abroad, in places where this type of toilet may not exist. I know the bricks most use are made of coconut husks and most of the places we will visit have no shortage of coconuts but for those of you cruising remotely, what has been your experience in finding those materials or do you simply load up and store them away while traveling?

[Checkswrecks]

I know a van dweller who just uses kitty litter and has used saw dust; both with no smell problem. Very few people are letting the waste sit long enough to compost, so these are really desiccating toilets. The two keys are separating the solid from the urine and airflow venting overboard from the holding portion.

btw, look into dimensions before buying. I found that I need to make my own after finding nothing from the big three composting toilet makers to fit in my head. Each is about 20-21" tall and will need to sit on a 7" shelf, making them the height of a desk, which is WAY too tall. Plus, the hull shape will displace them too far forward. Fortunately, this is a perfect application for use of 1/2" thick PVC sheet.
https://www.homedepot.com/p/1-2-in-x...0360/205079515
There are numerous BIY designs online like this:
https://sailingauklet.com/2013/09/22...mposting-head/

[john61ct]

Coir bricks can be a little hard to re-fluff, but is more space-efficient.

Anything sold locally for animal / pet bedding is fine. Kitty litter that's derived from wood waste.

Actual sawdust can be too fine, shavings are better.

Chopped straw's OK, horse bedding like chopped hemp stalks works, even collecting dried leaves.

Peat moss is cheap some places.

[goat]

Pet stores that sell lizards will carry coco coir.

I haven't tried this yet but I bet recycling coffee grounds (once you've let them dry) would also be an option.

goat

[laika]

We have coir onboard for when we need it, and search out other easier substrates locally.

As said, the coir is super space efficient but a PITA to break up. We grind it up first into large chunks with an electric drill and then more finely with our hands. Making about a months worth for two in the C-head takes a couple hours.

It is also important to us to find substrates which are non-toxic, preferably organic, as we empty directly into the sea and sometimes into remote non-populated harbors.

[captlloyd]

Originally Posted by laika

We have coir onboard for when we need it, and search out other easier substrates locally.

As said, the coir is super space efficient but a PITA to break up. We grind it up first into large chunks with an electric drill and then more finely with our hands. Making about a months worth for two in the C-head takes a couple hours.

It is also important to us to find substrates which are non-toxic, preferably organic, as we empty directly into the sea and sometimes into remote non-populated harbors.

Do you add water before breaking up ? That is key to my understanding. After breaking up the water soon evaporates/dissipates.

[Mike OReilly]

I can’t answer your question svspirited, b/c I’ve not ventured outside of Amazon’s reach. I’ve not heard of anyone having a problem, but it is a good question and I’m interested in reading the responses.

A couple of thought:

• It’s easy to carry enough coir for long periods. I usually stock about six months at a time, so stocking a year or two would be no big deal.

• As others have mentioned, you can use other bedding materials. Any disascociated material that absorbs moisture should work — some better than others though.

[laika]

Originally Posted by captlloyd

Do you add water before breaking up ? That is key to my understanding. After breaking up the water soon evaporates/dissipates.

It makes breaking it up a lot easier, but in our experience on a humid wet boat, sufficient drying time and space is not practical. And lot's of it will blow away and make a mess if, say, left out to dry in the cockpit.

Curious if others have had better luck tho.

[Mike OReilly]

Originally Posted by laika

It makes breaking it up a lot easier, but in our experience on a humid wet boat, sufficient drying time and space is not practical. And lot's of it will blow away and make a mess if, say, left out to dry in the cockpit.

Curious if others have had better luck tho.

Interesting comments about the challenge of breaking up the coir bricks. It is a task. I don’t perceive it as a problem, but it does take time and effort for sure.

My process is to place a brick in large zip lock. I add a cup or two of water, depending on the brick size. Then I leave it in the sun for a few hours. When I get back to the coir the brick is softer, but still pretty firm. I use a knife to pry it apart and then crumble it with my hands. Definitely takes effort though.

My approach is add the smallest amount of water as possible. Since these heads function by desiccating, keeping the bedding material as dry as possible seems to work best.

[jen1722terry]

Interesting comments.

We live aboard and our only head is an Airhead composter. We've had it 5 years We have the fluids tank plumbed into our 28-gallon holding tank, which we pump out off shore once every 3 weeks or so.

We only use peat moss. Easy to find just about anywhere and cheap. We load the solids tank with about half the amount that the manufacturer recommends, then add a cup or less every week or so. We also spray a bit of water into the tank after each deposit. And dump a cup of white vinegar in the liquids tank each week.

Someone said that the Airhead is not really a composter. That's true for live-aboards as the solids don't stay in the tank long enough to compost. When we empty the tank, the solids go in a double trash bag and into the marina dumpster.

One installation problem we had is the height of the Airhead. Someone with short legs may not have their feet on the head sole while using the head, not the best thing in rough seas. We did install a 1/2" starboard piece under the head which provides good footing to some shorter folks.

The payoff for us is no head clogs, a sure way to ruin a nice day.

[billknny]

Originally Posted by jen1722terry

We only use peat moss. Easy to find just about anywhere and cheap.

I guess this all depends on where you think "just about anywhere" includes. Probably not even close to most places cruising sailors actually want to go out side of the USA.

I am in Georgetown, Bahamas right now. As close to a major center as you can find in this country outside of Nassau or Freeport.

Nobody here has a clue what "peat moss" even is.

[alctel]

Try not to use peat moss if possible, as it's non renewable and wetlands are being destroyed all over the place.

Coir takes little room, is a waste product and works great (buy a ton of it before you leave) it's just an extra step to rehydrate it.

At a pinch I've used wood shavings from a pet store, worked fine.

[john61ct]

Moisture level is relative to your inputs of course.

You get familiar with your unique combination of factors over time, so using more water in the coir fluffing process, or using coffee grounds is just a matter of try and see.

I would suggest collecting used coffee grounds (too wet) adding to some too-dry compressed coir sealed up in a ziploc before it's actually needed?

Of course pine shavings are more pleasant if you have the space

[newhaul]

Coconut coir is what I use I buy bricks at my local gardening store
The bricks that I use ( my head gets full and needs changed about every other month)
but 30 days would be typical for most cruisers.
They are approx 4 inches by 8 inches by 1 inch thick .
I can easily store well over a years worth on the boat.


You have to add water to the brick to hydrate it for use ( mine come with a bag for that purpose)

[Mike OReilly]

Originally Posted by john61ct

...I would suggest collecting used coffee grounds (too wet) adding to some too-dry compressed coir sealed up in a ziploc before it's actually needed?

Do you do this John? How much ground do you use? I’ve never tried it, but might give it a go. We never lack for wet coffee ground on our boat.