Suggestions Please - Blackwater Holding Tank exhaust port threads stripped

[ThurstonCounty]

OK, so on recently purchased Vamos! (our E29 that we are bringing back), this weekend was the dreaded "replace all the lines in the blackwater system" because "the smell" is there. The handle on the y-valve was long ago broken off and it was stuck in the 'direct vent to the Chesapeake Bay' setting (a large no-no). Each pipe in the system was it's own 'vintage'



So I got all new pipes, a new y-valve, and while I'm mucking around in there, a rebuild for the jabsco hand pump.

Besides the incessant gagging on my part, it was not that difficult to remove everything (the breather hose from the holding tank was the most foul). The last thing to remove was the drain pipe from the holding tank to the 'suck out' port on the bow (through the chain locker).



The issue that I did not anticipate was that a previous installer had stripped the threads on the output port from the holding tank. This is the beige hard tank material threads. In the image above, the "work around" was to encase the screw on fitting, the tank, and the hose itself in a thick layer of silicon.

As a result, while the new hose is able to grab a thread or two in the attachment, the slightest pressure on it and it falls off. It is this captains policy that the exhaust port on your sewage holding tank IS NOT SOMETHING YOU WANT TO COME OFF.

Anyone run into this before? I'm looking for suggestions as I formulate a plan. Anyone tap new threads onto holding tank plastic before? Glue on an extension that has threads? Work on my silicon sculpting skills? Thoughts?

 

[Frank Langer]

Would it work to buy an ABS or similar material extension with same screw on end, that you could glue in place permanently with ABS glue, 5200 or similar, and then hose clamp to the other new end, so you can still replace hose in the future?
I think the company that makes these plastic tanks is still in business, though I can't recall the name at the moment, so maybe a call to their tech department might get you a good solution.
Frank

 

[paul culver]

If your E29 is like mine the installed plastic tank is 5 to 6 gallons. I crap bigger than that. Add a first mate and things get dicey real fast. I got a 14 gallon flexible bladder tank from IMTRA at least 10 years ago and it has not let me down. I installed it under the V berth on the port side. Its about $300 but all your fittings and threads will be pristine. Eat all the Chili you want !

 

[Loren Beach]

Measure your HT area carefully. Decide where you want your input and output connections in their best location. Often helpful to ignore the factory locations, or at least do not "assume" that they were actually perfect.
Buy a new tank from Ronco. They will 'spin weld' in all of the fittings exactly where you want. The cost will be very reasonable, IMHO.

Water / Waste Holding Tank - Ronco Plastics

Marine tanks are suitable for all marine plumbing, waste holding, and water supply needs. The tanks are rotationally molded of a seamless one piece, non-corrosive linear polyethylene and meet FDA regulations. Three female NPT (national pipe thread) fittings are provided free of charge...

ronco-plastics.com

If you look at my thread (different boat, but maybe you will find some stuff in common) I show some alternatives in our installation.

New Holding Tank, Piping & Valves

Tank News Here is a short update now that I have photos available. One with the demolition started and the other with new tank in place. The Rotozip and an old chisel were involved, along with some swearing. There will be more posted later to show the pump-out manual option being restored...

ericsonyachts.org

Not a fun upgrade/restoration, but once finished you can expect decades of odorless yachting...


Launch that ancient HT into a dumpster.

 

[goldenstate]

I second Loren’s suggestion to get a new tank if your threads are bad. Find the part number of your old tank and get the same one.

My freshwater tank came with three fittings included in the price.

How to replace a Ronco freshwater tank on a sailboat

sailboatrefit.com

 

[ThurstonCounty]

If your E29 is like mine the installed plastic tank is 5 to 6 gallons. I crap bigger than that. Add a first mate and things get dicey real fast. I got a 14 gallon flexible bladder tank from IMTRA at least 10 years ago and it has not let me down. I installed it under the V berth on the port side. Its about $300 but all your fittings and threads will be pristine. Eat all the Chili you want !

How was removal of the old one? Mine is glassed in and wraps around the v in the v-berth.

 

[Bolo]

IMHO, and from experience in this matter….replace the tank. If you try and glue critical things in place it will most likely fail you at the worst possible time, probably when the waste tank is full. When I bought my E32-3 16 years ago I had to replace the entire waste system, except for the toilet which I eventuslly replaced last year. Also, if you‘re sailing the Chesapeake bay then why a “Y” valve? You can’t use it. I sail out of Annapolis and will probably not be taking any long oceans excursions in the foreseeable future. When I upgraded the waste system the “Y” valve and whale pump were never replaced. The only way to get the waste out of the tank is by way of a pump out. The overboard waste sea cocks were all closed and capped. Also, one day I was boarded by the Coast Guard ,which I think was a training exercise more then anything, and the first thing they asked was to see if my “Y” valve was locked closed in place. When I showed them that I had no “Y” valve and that it was impossible to pump waste overboard they were very happy and so was I.

 

[ThurstonCounty]

IMHO, and from experience in this matter….replace the tank. If you try and glue critical things in place it will most likely fail you at the worst possible time, probably when the waste tank is full. When I bought my E32-3 16 years ago I had to replace the entire waste system, except for the toilet which I eventuslly replaced last year. Also, if you‘re sailing the Chesapeake bay then why a “Y” valve? You can’t use it. I sail out of Annapolis and will probably not be taking any long oceans excursions in the foreseeable future. When I upgraded the waste system the “Y” valve and whale pump were never replaced. The only way to get the waste out of the tank is by way of a pump out. The overboard waste sea cocks were all closed and capped. Also, one day I was boarded by the Coast Guard ,which I think was a training exercise more then anything, and the first thing they asked was to see if my “Y” valve was locked closed in place. When I showed them that I had no “Y” valve and that it was impossible to pump waste overboard they were very happy and so was I.

That is some great advice, especially married with that from Paul about pulling the old one out and putting in a flexible bladder one. I think I've found my solution to the smelly solution... ;-). Now, let me see how hard it is going to be to get this baby out from under the v-birth.

 

[Tin Kicker]

That is some great advice, especially married with that from Paul about pulling the old one out and putting in a flexible bladder one. I think I've found my solution to the smelly solution... ;-). Now, let me see how hard it is going to be to get this baby out from under the v-birth.

Wise man!

 

[ThurstonCounty]

Thank you EYO geniuses! My old tank had stripped threads and you provided the best response. The offending unit was half-ass-glassed in.



So I went at it and got it out.


While at it, I ripped out all the water system, skipped the y-valve, and took out the similarily aged water tank and associated hoses. A complete new system with fresh water rerouted to the toilet and flexible blackwater & freshwater holding tanks.

The smells are leaving after a full wash of the bilge. A repaint on it and we are golden! Thank you again for the encouragement and great ideas.

 

[goldenstate]

Thank you EYO geniuses! My old tank had stripped threads and you provided the best response. The offending unit was half-ass-glassed in.

View attachment 42782View attachment 42781

So I went at it and got it out.
View attachment 42783

While at it, I ripped out all the water system, skipped the y-valve, and took out the similarily aged water tank and associated hoses. A complete new system with fresh water rerouted to the toilet and flexible blackwater & freshwater holding tanks.

The smells are leaving after a full wash of the bilge. A repaint on it and we are golden! Thank you again for the encouragement and great ideas.

The old tank looks like a modern art statement of something about something. I'd call it "The genius of Vladimir Putin."

You're a brave man to tackle the job.

 

[Alan Gomes]

While at it, I ripped out all the water system, skipped the y-valve, and took out the similarily aged water tank and associated hoses. A complete new system with fresh water rerouted to the toilet and flexible blackwater & freshwater holding tanks.

I'm not sure what your plumbing diagram would look like, but in most instances you want to keep your fresh water plumbing completely separate from anything to do with the head. (There are some heads specifically designed to be plumbed into the FW system, but that is typically not the case.)

Peggy Hall is probably the world's expert on this stuff, and I know she frequents the Sailboat Owner's forum. You might contact her through that with more detailed questions. She's most helpful.