Stories of s/v Valkier,DE38:All the shit that accumulates #3 Composting Your way to Odor Free by Scott Carle

To see why we went composting read the articles that precede this one. All the shit that accumulates 1 and 2 🙂

After the previous experiences we installed a natures head composting head. The following composite article is a compilation of the installation and two years of usage and a few answers to questions others have asked us.


We installed the “Natures Head” composting toilet this past weekend. It fits perfectly side to side (read “it is a tight fit”) to get it in the head compartment  you take the top section off the bottom section. This is just a matter of unclipping two clips,one on either side of the unit and then sliding the top section left 3 inches or so as you lift it up to disengage the rear hinge. At that point both pieces will easily fit through either of the head doors.

Here is a few picture of the two stainless angle pieces that hold the unit to the floor. The first shows how we marked where to set the mounts. We put the head in place and them made sure that we had room on either side for the crank to turn on the right without hitting the wall and the latch on the left side of the unit to open as well as being able to slide the top to the left when pulling it off the hinge when removing it. Once it was spaced right we took a pencil and just drew a line around the backside of the angle pieces to mark where they went.

After drilling the holes with a 3/16 inch drill bit we placed the mounts over the holes to double check everything.

And then used 14×1 1/2″ stainless steal oval head screws to attached the brackets to the floor. I think though that I should have used flat head screws that would countersink a little bit farther. I will probably go back and change them out next week.


Once the brackets were mounted we set the head back down in place and attached the two thumb screws that hold it in place. It was a perfect fit! hip hip hurray!!!

Oh I forgot,we had to cut the nipple off of the fitting on the left hand side of the head to get the head far enough to the left so that the crank handle would turn without hitting the wall. the head comes with a left and right fittings that the vent hose can attach to. Since we are using the hose on the right side of the head we didn’t need the one on the left so we cut the nipple that the hose attaches to off the fitting. the square body of the fitting holds a filter in it though to allow air through but keep flies and such out so we needed to leave it in place.


You can see the hose attached to the fitting on the right hand side of the head. I brought the hose down and then back up to create a drip loop so that condensation in the vent hose will not drain back into the head itself. I have heard reports that this can cause problems in the composting process from other owners. So i thought that this would be a simple solution. My understanding is that it is only a problem in cold weather. The fitting on the left side of the head is identical to the one shown here. I cut the nipple off flush with the square box that holds the filter on that side. This side holds a filter and a computer fan. Oh the condensation running back to here will also eventually corrode and kill the computer fan if you are using that for your active ventilation.

The hose that came with the head was to short to go all the way to the
ceiling to attach to the dorade box so I used some  PVC pipe to fit it
all together. However I don’t really like the PVC solution and plan to
order a 8 ft length of the hose that will go the whole distance and just
replace what is there now.

To attach the hose to the ceiling they ship a little plastic fitting that has a nipple on it that the hose or in my case the PVC pipe will fit over. I drilled holes in it matching the screw mount holes in the bronze trim fitting on the underside of the deck that goes up to the dorade box. Then just got longer screws and screwed it all back up to the deck. Though you can’t see the whole thing I took some brasso and cleaned up the bronze fitting. You can see the edge of it showing gleaming.:) brasso and a scotch bright pad does wonders in cleaning up all the bronze fittings and trim on the boat.


You have probably noticed in the pictures that the headliner has been removed in the head and that we have the counter top taped off and it is painted white. We are going to sand the overhead down to get the roughest stuff knocked flat and then will be painting it a gloss white. At a later date if condensation becomes an issue we will put a headliner back in but we figure that with the shower in there it is going to have lots of moisture going on and that it will be easier to clean and keep up with. The old headliner had a lot of mildew/mold on it when we pulled it down. You can see in the above picture the discoloration from mildew/mold even after scrubbing with oxyclean and vinegar water solution. I am going to wipe it down one more time with clorox solution to see if that will go away before we paint it.

I will be adding some pictures to my original post on about the countertops for the rest of it.

We replaced the PVC pipe after a couple months and just ordered the right lenght of hose to go from the head, up the bulkhead and to the dorade box inlet in the roof of the head compartment. So far in two years of usage this has worked great. I still haven’t taken finished pictures as we haven’t painted the head ceiling yet.

After we have the head totally finished we will post some more pictures and after we have had a chance to use the head I will keep this updated on how well it works in actual usage.


One Year/14 Month review

Well it’s now 14 months or so since we installed the Natures Head on Valkyr. I have had several people ask me for an update on our experiences with it,so here it goes. Overall we are extremely happy with the change from a standard marine head and holding tank to a composting head. Both me and my wife would do it over in the blink of an eye.

Positives for us include

  • Overall total lack of odor.
  • Ease of changing the composting mix.
  • Regaining the use of two compartments under the v-berth and space in the port side v-berth hanging closet.
  • Ease of Maintenance and totally removing or putting the unit back in place.
  • Ease of initial installation compared to a standard marine head
  • 90% less maintenance than a standard head and what maintenance you do end up doing is much less nasty.


Downsides so far

  • Height of unit installed in a DE
  • Frequency that the Urine container has to be changed and dumped.
  • Dreaded gnat infestation.
  • Units don’t handle diarrhea well
  • You spend more time making sure the bowl is clean each time you use the unit. (very small downside,wasn’t shure I should include it as a downside but you do work at it harder than with a standard marine head.)


We have found that in actual use that the head and head compartment actually smells as fresh or fresher than the rest of the boat,this over a year of part time to full time use.  It is so nice to not worry about obnoxious odors coming from the head compartment or making the whole boat reak. It even passes the wife test with flying colors.

In practice for part time use to full time use while living at the dock we have changed the compost at intervals between six weeks and 6 months.  I think that living on the hook full time we would probably change it between once a month and every six weeks. Changing the compost is a simple matter of removing two hand knob screws that attach the unit to the floor,then removing the top of the unit (a matter of unlatching two latches and the exhaust hose). You then  can take a standard kitchen trash bag and stretch the top of the bag over the top of the base of the composting head. There is a molded in groove that it will lock into when stretched over the top. Then you simply pick the unit up and turn upside down and shake the contents into the trash bag. Typically we have found that the contents will take up about 1/4 or less of the volume of a standard kitchen bag. We,then depending on the situation,will dispose of the the trash bag in the dumpster or more often take it home with us and dump under some of the shrubs or trees at the house. Re-assembling the unit is a simple matter of attaching the base back to the brackets holding it to the floor then placing the top back on it before latching the two latches. The whole process only takes 5 or 6 minutes at the most. Just prior to putting the top back on or even after the top has been re-attached we will add the new composting mix. In normal practice we do not clean the bottom compartment. This leaves enough of the existing compost mix with it’s developed compost to quickly get the new composting material going. It has been recommended to us that using a scoop to remove 70 or 80 % of the compost rather than removing the head and dumping it entirely is easier and leaves more mature compost to get the new material going. We have not tried this method yet though.

Normally you charge the unit with 1.5 to 2 gallons of new composting mix. We use ground and compressed Coir bricks (coconut husk). To use them we will take one brick (about 2.5 inches by 6 inches by 10 inches log) and add a gallon of water in a 5 gallon bucket. A couple hours later you can just break it all up in to a moist earth like mixture. If it is still a little dry you can add a little more water. You don’t want it to get to wet though. One brick will create about 2 gallons of compost mix.

We regained,I would estimate,30 or 40 cubic feet of usable storage space after removing the old plumbing and holding tank. In our boat the hoses and holding tank were very old and were permeated with odor. In the port side hanging closet,even though the hoses only took up one side of it,we didn’t use the closet because anything placed into would absorb the odor of the hoses. So we did not use that space except for tool boxes or some hard parts etc..  We have now regained full use of it. The small compartment under the seating area of the v-berth used to hold plumbing and a whale type pump that had a leak in it. After removal of the plumbing and pump we gained that entire area for storage. Like wise the large compartment under the v-berth that used to hold the holding tank.

When talking about changing the composting mix I spoke of how easy it is to take the unit apart and dump it and how quickly. To give a better example,we recently received a upgraded stir bar made of thicker stainless with a smaller three handle crank that fits in our boat better than the stock handle on the older stir bar. We had not emptied the composting compartment in the six months prior to this. Removing the head,dumping it,cleaning it out totally so what we felt  comfortable handling the old stir bar to remove it and put the new on in its place and then re-assembling the unit in the boat and placing new compost material in it took about 20 minutes total. Not once did it smell nasty or make my over developed gag reflex kick in.  The roto-molded plastic that the head is made of is just this side of Teflon slick,and when dumping it,very little was stuck to it after a years use. It dumped out almost clean. The stainless stir bar did have solid matter stuck on on it in several places. It cleaned off easily with a hose.

Even the initial installation went very quick and easy compared to a standard head and plumbing. Installation consisted of mounting to L brackets to the base the head sits on that hold it down. Installing the ventilation hose which consisted of mounting 3 or 4 brackets up the side of the head bulkhead and on the overhead to run it to the opening to the overhead dorade box and then mounting a solar nicro vent in place of the cowl on the dorade. In all the entire project probably only took 3 or 4 hours of actually working time. Most of the time was spent on measuring for mounting the head itself to the platform,running the hose and mounting the nicro solar vent.

So far in the last 14 months the only maintenance we have done is replacing the stir bar and that was an optional upgrade. The unit worked fine with the old stir bar,the new one is just a bit heavier construction and with an easier handle for the space on our boat to turn it. Over all the maintenance needed for these units is minimal to none. We don’t use the built in fan on the the head which I would estimate would need replacement every  two or three years. Though as I will explain later we might start using it in conjunction with the solar vent that powers the ventilation now.

We have found the installed height of this head to be slightly inconvenient. A standard marine head is very short and most boats have a built in platform that bring them up to a usable height for the average person. The Natures head on the other hand is of a standard height already and does not need a platform to make it the right height. On our boat the platform is built in such a place that you can’t remove it and have a level place to install the head. The Natures Head fits perfectly on the existing platform other than it is about 7 or 8 inches higher than we would like. Due to the constraints of having a composting bin built in the base we don’t see the likely hood of anyone building a shallower unit. This leaves us with tall people being just higher than is normal and for a shorter person their legs dangle when using the head. We plan on installing a little foot platform in front of the unit to overcome this issue. Regardless in the last year no one has not been able to use the head and even if we couldn’t retrofit a little foot platform to make it more comfortable we would still regard this as a minimal issue compared to our problems with standard marine head systems. As the manufacture will tell you these heads are mostly marketed to the home/cabin/rv markets that normally have a bathroom with no platform to raise the head up. For that they work very well. If you have room in your head compartment to install one flat on the floor then you are golden. Even with having to install it higher up we feel it is worth it.

For me,having to empty the urine container every two to three days is my biggest complaint. With three adults full time on the boat it needs to be emptied every couple days. For two adults we find that we need to empty it every third to fourth day. For a single individual I would anticipate that you would need to empty it about once a week. We already knew about this issue before buying the unit and on the recommendation of others that own one as well as it being recommended by the manufacture we purchased extra urine containers. I would recommend this to anyone that is thinking of getting one of these heads. It allows you to change it out in the middle of the night and defer actually dealing with dumping the full bottle till the next day or even the day after that. Changing out the bottle is a matter of about thirty seconds of time. You remove the cap of the empty bottle ahead of time,unlatch the two latches that hold the top of the composting head to the base and pivot the front of the unit up about thirty degrees on the back hinge. Screw the cap on the full container as soon as you can and then using the carry handle lift that bottle out and then place the empty bottle in its place. Lower the top and re-latch. You are done. We have three bottles and that allows us nine days before we have to dump if needed. Mostly we carry the full ones back to the house and dump them there. However you can also dump in a toilet or,outside the 3 mile limit in the US,you can dump overboard. Dumping the urine containers is probably the nastiest thing about the entire process,however we don’t find it so bad that we would go back to a standard marine head. If you dump the containers as soon as they are full the odor isn’t that bad. If you let them sit for a few days they can smell pretty bad. We have been told of various things that you can add to the container that reduces this odor but haven’t actually tried any of them yet. When installed on the head we don’t find that there is any detectable odor from the containers.

Since these heads don’t flush with water you have to clean the bowl every time you use the head if you get the bowl dirty.  This is actually much less of a problem and easier to do than you would imagine. After using the head two or three times you will find that you get good at getting solid wastes to fall through the trap door on the head without getting any in the bowl. Urine that goes in the two forward drain holes in the bowl is easily rinsed out after every use with a little dribble of water from the shower hose in the head or using a spray bottle of water. If you do get fecal matter in the bowl just take a handful of toilet paper and wipe down and into the composting bin. Toilet paper always goes in the composting bin where it will compost also. Then we keep some clorox wipes in the head to give the bowl a sanitising wipe down if needed. The roto-molded plastic the head is made of cleans very easily this way.

The are two issues that are probably the biggest downside we have hit in the last year. The first is diarrhea,inputting that much water/moisture into the composting process overwhelms it. I had an unfortunate run in with a stomach bug a month ago.  The head started to have an odor when you opened it. Throwing a handful of fresh compost and giving it about three days of time for the ventilation system on it to work got it through that,but an extended bout would soon overwhelm the head. I was actually impressed with how quick the system bounced back and think that if we wired in the fan that is built into the head  and ran it in conjunction with the nicro solar vent that it would accelerate ventilation and carry off the excess moisture faster. I would want to install a switch in the head compartment to turn it on or off as we would still depend on the solar vent for primary ventilation and the built in fan just when needed.

The second issue is that we seem to have picked up a gnat issue in the head. This is also something that is a known problem with these systems. It is annoying when it happens. We purchased a Hotshot product from Lowes that you hang up and it emits vapors that kill flying insects such as flys and gnats. It is not recommended for use around people so we did not hang it in the head compartment. instead we placed it in the composting bin itself. It seems to be working at suppressing the gnats. There are still a few but not nearly as bad. The next time I will pull the permeated pad that is in the plastic unit and cut it into small squares and throw them in the head. The whole unit is really too big to fit and can get in the way of the stir bars. With the poison in the head  and positive ventilation pulling any fumes to outside the boat we are not worried about issues of it us being affected by it. From what we have heard the only true solution is to remove the whole head,then empty,clean and sanitise it to get all the eggs.

So the good the bad and the ugly. If you stop us on the dock and get into a conversation about heads be prepared for us to rave out our composting head. We think that is has over all improved our quality of life on the boat by a factor of 2 or 3. It is one of those products that we think its time has come.

I can’t really think of anything else. That’s about as comprehensive a report as I could come up with. If you have any questions about anything I wasn’t clear on let me know:)


Ok we are coming on year two of use and here are some thoughts and answers to questions we have had on our Natures Head Toilet.

Guests on board

Something else I thought about as a downside to these. When we have guests it is still as hard or harder to explain how to use these as it was a standard marine head. At least we don’t worry about people putting toilet paper into this one but having to explain that poo and pee go in separate holes and that you have to rinse or clean up after yourself every single time you use it seems to generate a lot of resistance. We now have people we would prefer not to visit us on our boat because of the mess they left behind on the composting head. At its messiest (oh shit I missed the hole) it is still a simple matter of a minute or so to wipe the mess down the open  hole to the composting bin and spray with water and wipe down again and then maybe spray a disinfectant if needed. In regular use you just about never need to do this but guests that have different attitudes or lack of ability to use it as described can be a trial.

On the flip side I had plenty of people like that on my “shit” list for messing up my standard marine head by improper use. At least now I don’t have to take shitty plumbing/pumps/hoses apart or rebuild any of it on a semi regular basis. Both then and now if your a guest you need to sit to do your business if you aren’t willing to then you better take your business with you and not share it with us. We have a very low threshold for those that want to stand and urinate. As used the head is always immaculate and odor free. If you treat it like a house toilet it will start to smell like a house toilet with urine spattered around it on the seat, the outside of the unit, the head walls etc. Our attitude is that as a guest and after we explain how it works and why that if you decide to do it your way and leave a mess for us to clean up that it speaks to your respect of and for us. If you don’t respect us then I guess you don’t really need to hang out with us.

Current Usage

right now for the last couple months we have been spending about 3 to 4 days a week on the boat again and the last time we changed the coir was 9 or 10 months ago. We keep talking about doing it as it is time but we have no odor and the  stir rod is still fairly easy to turn so every week or two I dump a single cup of extra coir into it and we just keep using it. I find that if usage isn’t keeping it moist enough that it helps to spray a few squirts of water in it once in a while to keep the coir from drying out. If it dries out it tends to clump and then be hard to stir.

Cost comparison and general maintenance

Our standard marine heads cost us on average 120 dollars a year to use between rebuild kits or hoses that needed replacing, chemicals for  the holding tank, pump outs etc.. The composting head once installed I think we have spent about 60 bucks for enough coir for 2 to 2.5 years and maybe 20 bucks on a can of raid and one of the flying insect killer things. This gives us a rough 30 to 40 dollars a year operating cost. Oh and the cost of a trash bag every 6 weeks to 6 months depending on how much we are on the boat to dump the head into  when we change it out.

The only maintenance I have done to the unit is that I upgraded the stir rod to a more robust model the manufacture came out with. Not that the old one didn’t work but the new one had a lower profile turn handle that was easier to use. We dumped the head and washed it out and put the new stir rod in. Total time taken was about 20 minutes from pull it out of the boat to put it back in the boat. No grossness, no odor. When we dumped it pretty much everything fell out the only stuff that stuck was on the stainless stir rod and a hose spraying it out got rid of that in a minute or so.

Thoughts on cleaning

We have a one quart or so spray bottle of plain water that we rinse the urine portion of our natures head with every single use. It puts very little water in the holding tank and so far has worked great to keep it clean and odor free on the urine section.As for the composting part, once you have used it a while you good at doing your business into the bin without touching the opening. No clean up needed 5 out of 6 times. Just throw the toilet paper in on top of the poo and close the trap door and turn the mixing handle fully around 4 or 5 times. If you do get a stain we just spray it off with the spray bottle and then wipe the bowl or opening clean as needed. Disinfect as needed. The rotomolded plastic of the natures head is so slick it’s kinda like using a teflon skillet. Nothing really sticks to it. I would never use any abrasive cloth/pad/cleaner ever on the rotomolded units. As soon as you scratch the surface it will start to cling to fecal matter and urine much harder and be that much harder to clean in the future.


Gnats in the head

We had gnat issues last summer and it was annoying but a few shots of bug spray into the head slowed them down. We then purchased a product that you hang in closets or garages etc that kills flying pests. It is labeled that you not use it if you are living there but we figured the head doesn’t exchange air into the boat. So tried it anyways. Seemed to work. Purchased it at home depot in the pesticides section of the store.

We didn’t add anything back the next change of compost and so far haven’t had an issue since. I think it is definitely something you should expect to face at one time or another in your use of these heads. The natures head doesn’t seal totally. there is a little room around the forward edge of the trap door that opens into the body and I think that there is also airways from there that go to the Urine holes also. the fan pulling air through keeps all odor out but I think gnats could get through there to infest the compost. That being said we have been using it for two years now and only had gnat issues for about a month and a half of that. A shot of raid into the head once in a while just about totally suppressed them. To really clean them out you need to clean the head inside and out factory clean and get them out of the boat also. We just suppressed them till they didn’t come back. Your millage may vary depending on how you try and fight them.


Even though we have faced a couple of downsides to this style  head we would still hands down do it again. There has been no needed maintenance at all and only one time of a upgrade that I wanted but didn’t need. We haven’t had to “Pump out the Head” since we got it. No liquid Poo and Urine soup. Though we do have to dump the head, it ends up averaging every 4 to 5 months or more for our part time usage. The urine containers are probably the single most not fun thing about using it. But compared to my old We have a one quart or so spray bottle of plain water that we rinse the urine portion of our natures head with every single use. It puts very little water in the holding tank and so far has worked great to keep it clean and odor free on the urine section.

As for the composting part, once you have used it a while you good at doing your business into the bin without touching the opening. No clean up needed 5 out of 6 times. Just throw the toilet paper in on top of the poo and close the trap door and turn the mixing handle fully around 4 or 5 times. If you do get a stain we just spray it off with the spray bottle and then wipe the bowl or opening clean as needed. Disinfect as needed. The rotomolded plastic of the natures head is so slick it’s kinda like using a Teflon skillet. Nothing really sticks to it.

I would never use any abrasive cloth/pad/cleaner ever on the roto-molded units. As soon as you scratch the surface it will start to cling to fecal matter and urine much harder and be that much harder to clean in the Beneteau F235 with a 13 gallon holding tank we only dump them about the same frequency we had to pump out when staying on board it and it is less nasty to dump them than it was to pump out. So in conclusion this has been one of the best upgrades to the boat we have done.  It has added to our comfort level in its ease of use, lack of odor, and the relatively little upkeep it takes in using it.

I hope that my ramblings help someone out 🙂 just some of our thoughts on our Natures Head after a couple years.

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6 comments to Stories of s/v Valkier,DE38:All the shit that accumulates #3 Composting Your way to Odor Free by Scott Carle

  • Thanks Scott for an exhaustive examination of the issue. I have never before seen such a detailed review.

    s/v Eolian
    DE45 #11

  • Maybe I will clean it up and submit it to some of the boating magazines. 🙂

    Maybe it will make a 2 or 3 part article.

  • avatar Slowride

    We have an AirHead composting toilet on our DE38 and wouldn’t trade it for the world! Can’t imagine ever having a holding tank again. I would recommend a composting head for any boat owner. One little trick that we have is to put about 2 tbls of vinegar into the pee bucket after emptying and then we keep a small spray bottle of half water, half vinegar to lightly spray after each use. Keeps the bowl clean and eliminates any “pee” smell.

    We also had the gnat problem and took the same approach as you and it worked great.

    Great read! Thanks

    Mike and Julie

    • Hey Mike and Julie,
      Good to see you guys taking advantage of the site. 🙂

      I need to do a 3 year update on the composting head article for the gnats. We had a battle royal with them last summer 🙁 The shot of hot shot into the head and the product we were cutting up and putting in it helped but didn’t stop it dead. It was really getting on our nerves so we tried diatamacious earth and it seemed to work after a cup or two thrown in and stirred up. However as you use the head the diatamacious earth over time doesn’t stay a powder 🙂 it turns into more of a glue as it mixes into the damper contents of the compost. It then loses its effectiveness. I then had a thought and went to wall mart and bought a container of mothball crystals and sprinkled two or three tablespoons of them into the head. It killed the gnat problem DEAD! DEAD! DEAD! They lasted for weeks so we didn’t have to add them on a regular basis. It takes a while to get the right amount. better to go light and build up to the correct strength than to do the over kill. Moth balls are cheap and long lasting I hate to use any poisons on the boat but this is what finally did a 100% cure for us on the gnat problem. The prior solutions would suppress them for a week or two at best and make it livable and usable, the moth balls seem to be the 100% solution at this point.

      We found the the vinegar and water solution for rinsing the head with a spray bottle also. You have to love vinegar it is the swiss army knife of household chemicals, you can eat it and use it in cooking, preserve food in it, clean with it, kill mold and mildew with it, use it medically, plus much much more 🙂


  • avatar Slowride

    There should be a site just for vinegar uses(maybe there is…) 🙂

    Actually headed to Walmart this morning and have put moth ball crystals on our list. We haven’t had any problems with the gnats recently but want to be prepared. My wife would rather pee in a bucket than use the head when there’s gnats……

    • I hear you.. We only have issues in hot weather.. sometimes no issue sometimes there are gnats. once you have them though its a pain to get rid of them. At least it was untill we started using the mothballs/crystals. Just make sure the air vent is working so that it sucks all the vapor from them out of the boat. 🙂

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