I recently replaced the big waste hoses of the heads. Reason was that I had the impression that build-up inside the hoses was constricting the flow.
While the hoses were not as plugged-up as I thought, the outlet side of the holding tank
was almost plugged up completely.
For another reason replacement was very useful: the heads and even the saloon
became notably less smelly. (the smell of the original, more permeable hoses could sometimes reach the saloon
via the anchor hatch
; this is all open....).
Also, the risk of the system plugging up by accidental toilet paper in the toilet becomes less.
the job took me around 5-6 hours, working carefully.
Required: big cork to fit into the 38 mm hose; 3.1 meters of anti-smell hose; at least one surgical glove; tools; vaseline; white silicone caulking; noseplugs.
We have the Mahe version with a black water holding tank
The hoses are 38 mm internal and 50 mm external; probably equivalent to 1.5" and 2". Original production hoses were standard hose, I think; the text in the hoses says "waste", but you could smell things straight through the plastic that you don't want to smell.
See the picture of the original hose from toilet to inlet side of holding tank.
In shops in La Rochelle, where we visited, I found standard hose for 13 euro/meter, and anti-odeur (anti-smell) hose for 25 euro/meter. Obviously I purchased the latter.
The job itself is a bit smelly and messy. Not bad to use latex or surgical gloves.
First you have to remove the fiberglass
cover around the holding tank, 6 crosshead screws.
Then insert a water hose in the deck
outlet of the holding tank. Fill the holding tank with water, with the through-hull valve closed; when the holding tank overflows, open the valve; look out of the window. Continue this process until the water from the holding tank becomes clean; this might take 10 times....
Next step: pump a lot of clear water, preferably from the boat's sweet water, through the toilet. Then pump lot of air through, to remove as much water from the long hose (going to the holding tank) as you can.
I then removed the hose between holding tank and through-hull valve. First on the top side, below the holding tank. When you remove the hose at this side, immediately put a dispensable container (eg from a Chinese restaurant) below the holding tank outlet.
I then removed the hose between toilet and holding tank.
First disconnect this hose at the top (holding tank) side.
Next you undo this hose at the toilet side. You need to remove the toilet outlet elbow
and the anti-flowback valve of the toilet for this. Keep the silicone caulking around the hose intact till now.
Unavoidably the contents of this hose will run into the bathroom, (unless you do something clever with hoses, and use a pump from the holding tank side, to empty the hose).
After drying around the toilet base, you can cut the silicone caulking around the hose, pull the hose a bit upwards behind the toilet, and put a big cork in it. The avoids the not-so-clean contents from running between hull
and heads inner shell, where it is hard to clean. Then remove this hose with the cork in it.
It was 2 meters exactly, but it is better to replace it with 2.1 or 2.2 meters. This makes re-mounting at the rear of the toilet easier, with less stress (= change of leaking) on the toilet outlet elbow
I then cleaned the outlet of the holding tank, and the inlet of the through-hull valve, using my fingers in a surgical glove. This was quite useful, the biggest constrictions were here, especially the outlet of the holding tank.
Then install the new long hose.
Then install the new short hose. This hose is just under one meter, so best is to purchase
a length of 1 meter and once in place cut it to exact length.
Apply silicone caulking between the long hose and the heads inner shell after cleaning
the glued area well with acetone or alcohol.
As standard maintenance
, re-apply vaseline on the cylinder and piston of the toilet pump.