holding tank? Unless the inside of the tank is epoxy
coated you will over the years start to smell the contents. Holding tanks are normally made of polypropylene which is a translucent type of plastics that has a slippy, waxy feel to it. The very close linking of the molecules do not allow any gases, etc. to migrate through the walls.
- - Using hard "pvc" pipe to plumb from the MSD to the tank - and into the tank - without any "flexible" joints is again asking for leaks
migration. PVC pipe is not as smooth inside as you might think. Over time debris will "glue" itself to the inside of the pipe and eventually clog off the pipe just like normal vinyl hose does (scale build-up) over time and use - especially if you are using a sea water
to flush the MSD.
- - Boats flex and bend as they travel up and over waves and take a pounding in every conceivable directions. Wiring
standards and plumbing
standards are very, very different from land housing standards. Everything in a boat needs to be able to flex in all directions and not break or separate/crack which is why vinyl hose, etc. is used in the plumbing
- - If you are only going to have the boat for a few years, no problem, but if it is a major investment for long time use, then I can foresee serious problems ahead. Look into the heads and bilges of boats in the boat shows and you will see what is being used and how it is connected. These manufacturers do not want to have serious problems coming back to bite them years down the road so use materials and techniques that are proven to work.
- - I installed a "grey" water drain system in my boat in anticipation of future governmental regulations
about such things as sinks and showers. There are threads about Turkey
and grey water regulations
. I did use pvc pipe for the 30 foot run from the forward head to the engine
room where the grey water tank is located. The pvc pipe is sloped and held with tiedowns every 2 feet. Flexible hoses connect the pvc pipe to the tank and sinks/showers. And - - 10 years later, the pvc pipe is clogged with debris and cannot be removed or cleaned short of ripping out the whole sidewalls of the boat. A great idea that did not work in reality.
- - Bottom line - If you plan on only having the boat for a few years at most, then no foul, no harm. But if it is a very long term investment I would seriously suggest ripping out that tank and pvc piping and use "normal" accepted/proven standards for MSD plumbing and MSD rated hoses which are different from the normal vinyl hoses used for other systems in a boat. I believe SeaLand sells the special hose.