Head Replacement-Sanitary Lines?

[Curiousgeorge206]

Recently purchased a 1984 C&C 30' Mk II. In the midst of replacing the the original leaky head with a compact Jabsco head. The 1 1/2" sanitation lines are the old black lines, in the midst of swapping them out with the new white flexible pvc approved sanitation line, however, having a problem removing the old lines due to them being embedded on there for the last 30 years.
First question, is there an easier way of removing the old lines other them a utility knife and trying to pry them off with a flat head screwdriver?
Second question, the new white pvc sanitation line is virtually impossible to connect to the new fittings. I've tried boiling water, works for part of the hose but cools down too quickly for the other end of the connection and not practical in tight spaces. Someone has told me to use a heat gun. Will a heat gun destroy the composition of the pipe, of course not to get it too close tho. Or does someone else have another alternative way of doing it?

Of course in the old C&Cs the piping is underneath the sink compartment so space is ver limited. I've decided to move the piping over to the v berth and add a Whale gulper pump.

Thanks for all your help!

 

[jibes138]

Try a hair dryer first, it might be enough heat but not too much. Boiling water works good but you have to get the hose on the fitting quick. Maybe use a little liquid soap to help it slide on before it freezes up. Heat guns have two settings but your problem will be one side of the hose will get hot while the other side not so much. Keep the hose in the boiling water for a while to make sure it gets up to the full temp, and use a big reservoir of water, otherwise the water cools down as much as the hose heats up.
I recommend an oscillating tool with a metal cutting blade to get out the old hose. The hose has a metal wire in it so you need more than a knife to cut through it. An oscillating tool will have it cut in seconds.

 

[woodster]

i don't remember having a problem hooking up the trident 101 hose on my fittings...i tried the shiny plastic hose and it would not budge with out heat so i elected to use the trident hose and after reading a lot on here about this subject learned that the 101 will last a lot longer with out permeation.......

 

[gettinthere]

The white pvc will stink, sooner or later. Not sure what "approved" means.

By far, the best and only good choice is trident 101 (black) or trident 102 (white). These are double wall hoses that have proven to resist odors for over 10 years. I've had 101 in most of the boat for about 6 years with no smell. But one short section was your white pvc hose and it started stinking in about 2 years.

I also found 101 to be MUCH easier to slip onto a hose barb that the pvc crap. That stuff requires a lot of heat to make it pliable and it isnt hard to overheat and weaken the hose making it susceptible to failure.
I have never seen, heard or read of anyone having odor problems with trident 101.

 

[hunter healer]

I just did a refit and I used a mini hack saw to cut the hose then i cut a cross cut on the hose at the fitting going slowly not to cut the under pipe then I could pry it open with a screw driver carefully

 

[31seahorse]

The white tubing has a reinforcing rib curving around it. If you treat that like the threads on a screw you can turn the tube to ease the connection on at least one end. Do be careful with the heat gun because the tube gets soft and will collapse as you push on it. After that extreme softening it will not be useable again. The liquid soap application has helped me in some connections. I have only used the white, single walled tube and have found it satisfactory once it was "cussed" into place. Check the discussions in the Search of Forums to get more info on this unappealing aspect of sailing.

 

[wflowe2]

Handheld heat gun

 

[Ralph Johnstone]

in the midst of swapping them out with the new white flexible pvc approved sanitation line,

Definitely not a good idea for handling sewage. Fine for the supply of sea water to the head. Use a sewage hose from any reputable manufacturer.

A hair dryer is the most used tool on my boat. Everything from fuel lines to water lines to sewage lines are much easier to handle once they're heated. Be sure to allow enough time to heat through the tube wall. I'd be cautious with a heat gun as it can supply enough heat to damage the hose whereas a hair dryer is more forgiving.

 

[thinwater]

Definitely not a good idea for handling sewage. Fine for the supply of sea water to the head. Use a sewage hose from any reputable manufacturer.

A hair dryer is the most used tool on my boat. Everything from fuel lines to water lines to sewage lines are much easier to handle once they're heated. Be sure to allow enough time to heat through the tube wall. I'd be cautious with a heat gun as it can supply enough heat to damage the hose whereas a hair dryer is more forgiving.

Intake. The white hose is not reinforced, so I'm not certain it is suitable for use below the water line. It is also leak-prone under pressure. The are other water / exhaust rated hoses that are more suitable. It is not sewage and thus sanitation hose is not required or recommended.

Vent. You will need to use white hose for the vent, since Trident 101 and other premium sewage hoses are not available in smaller sizes. However, the smaller hoses are pretty manageable with heat. Don't even consider clear vinyl; it will permeate within months and will kink closed.

 

[Curiousgeorge206]

Thanks for everyone's help and advice. With the assistance of a heat gun and dish washing liquid as a lubricant, managed to get all sanitary lines replaced! The Jabsco head works great!