Head Plumbing

[mwrohde]

I am giving some thought to replacing the holding tank (bag, in my case) and plumbing on my boat. I'm aware that the recommended replacement hose is OdorSafe, but at $8 a foot . . .

Why wouldn't I, couldn't I, plumb the head to holding tank with rigid PVC? Is there a reason other than pulling flexible plumbing is easier?

Thanks,

Matt

[Joel73]

I would think that rigid PVC would crack over time with the stress of being underway... but maybe it could work for your set-up. I will be replacing ours soon and i expect i'll use flex.

8/ft?????

[RAGTIMEDON]

The vibration and flexing of the boat will cause the pvc glue joints to crack. You can buy cheaper flexible hose, but the good stuff is 8 bucks a foot! Is your nose worth 8 bucks a foot? Or is your wife's nose worth 8 bucks a foot?

[SVCarolena]

Originally Posted by Joel73

I would think that rigid PVC would crack over time with the stress of being underway... but maybe it could work for your set-up. I will be replacing ours soon and i expect i'll use flex.

8/ft?????

In addition, PVC generally requires a number of somewhat sharp turns (i.e., 45degree elbows) to get where it is going. This makes it hard to install and creates potential blockage problems. Try to design a system with the shortest runs possible, which will reduce the amount of hose needed and the amount of water used, buy the good stuff, and then you will be good to go for a number of years. What type of boat are you converting? I'm still working out the best solution to replace the bladder system on my P303.

[sailingdog]

The main difficulty with rigid PVC pipe is as Joel points out, the fact that it tends to crack. It has been used with some success on some boats I've seen, at least for the longer static runs, and prevents the issues with odor permeating the hoses.

One thing about the SeaLand OdorSafe hose is that it will probably out last the cheaper stuff... one major source of hose odors is the hoses becoming permeated with the sewage and then the hoses themselves become a source of odor.

[Traveling Light]

I used PVC for straight runs and flexible hose for not so straight portions. For the angles I used a black flexible plumbing pipe (I can't recall its name, maybe Fenco, but I purchased at HD). It has worked great and I have had it in place for four seasons - this is the start of the fifth. The elbow sections are connected to the PVC with worm type hose clamps (SS of course). Another owner of a boat like mine - Pearson 28-1 - suggested this approach and pointed out that it makes it easy to get to a clog, has not happended yet, if needed. The PVC has not cracked and there is no smell. I believe the flexible joints eliminate potential stress which would cause cracking.

[mwrohde]

Thanks for the replies, guys. Good information.

The follow up question is the bag that I've currently got in the boat (Cal 3-37) - it's a 12 gallon black bladder that says it's for diesel and holding. Is this likely to be permeated and causing smell as well, or is it something that if it's not leaking then it's still ok?

[sailingdog]

If hoses can permeate, so can the bag. Easy way to check...Get a cloth, wet it with near boiling water, drape it over the bag or hose, wait a few minutes, pick up the cloth, sniff. If it smells like sewage, the bag/hose has permeated.