Sealants for Holding Tank Fittings?

[thinwater]

From Ronco site:



"Plastic tank connections are designed to seal dry. Compounds such as sealants, pipe dopes, greases, petroleum jellies, glues or adhesives are not to be used. Normally, hand tightening will provide adequate seal. On occasion, a slight tightening with a wrench may be required. To avoid damage to seal fittings, do not apply excessive force. Do not exceed 1/4 turn after hand tightening."


Just sayin', not knowin'.


I've always used yellow gas tape (boats and long industrial chemical industry experience) and have never had any issue. Gas tape is thicker and seals with less force.

[Kupe]

Originally Posted by a64pilot

Way I see it is that I can always tighten just a little more if it was loose to start with...

Ahhhh, would that that were true in this case. The problem is the outlet elbow at the bottom of our holding tank. Due to its proximity to the hull floor, it is impossible to rotate it more than a few additional degrees without almost completely removing the tank. And then I would have to be able to do pretty much an additional full turn to meet the hose again in the narrow space. A two day job that I just finished and wish never to do again.

But knocking wood loudly- the jobs seems finished and all is dry after several days aboard. Thanks everyone for the amazing help!

Kupe

[malbert73]

Originally Posted by thinwater

From Ronco site:



"Plastic tank connections are designed to seal dry. Compounds such as sealants, pipe dopes, greases, petroleum jellies, glues or adhesives are not to be used. Normally, hand tightening will provide adequate seal. On occasion, a slight tightening with a wrench may be required. To avoid damage to seal fittings, do not apply excessive force. Do not exceed 1/4 turn after hand tightening."


Just sayin', not knowin'.


I've always used yellow gas tape (boats and long industrial chemical industry experience) and have never had any issue. Gas tape is thicker and seals with less force.

Hi all-
Resurrecting this thread as I am about to install a new Ronco tank in my T40.
Any concerns about using schedule 80 PVC threaded fittings? I will be using PVC for some of plumbing leaving tank to prevent hose permeation issues over time.

Also, I read with great interest the "no sealant" recommendation on Ronco website. I want to follow their thoughts, and this makes me nervous. Others? (Peg, Thinwater?) Tape would maybe be harmless?

[peghall]

Originally Posted by malbert73

Hi all- Resurrecting this thread as I am about to install a new Ronco tank in my T40.


Any concerns about using schedule 80 PVC threaded fittings? I will be using PVC for some of plumbing leaving tank to prevent hose permeation issues over time.

Also, I read with great interest the "no sealant" recommendation on Ronco website. I want to follow their thoughts, and this makes me nervous. Others? (Peg, Thinwater?) Tape would maybe be harmless?

PVC fittings not a problem...in fact, if the discharge fitting is at the bottom of the tank, it's a good idea to use PVC pipe to the top of the tank, then switch to hose the rest of the way.

Teflon tape, and plenty of it, is the ONLY sealant I recommend using on threaded tank fittings. Nothing but dishwashing liquid--or better yet, K-Y, on the barbed end.

Be careful not to over-tighten threaded fittings...they're NPT standard, which is slightly tapered--too slightly to see with the naked eye in a female fitting that short. Over-ightening will result in a cracked female collar, if not immediately sooner or later...I've seen it take a few months.
So just a quarter turn past hand tight is as tight as you want to make 'em.

If you haven't already bought hose, Raritan SaniFlex RaritanSaniFlex hose is the best choice. It's proven to be 100% odor permeation resistant and has the added advantage of being so flexible it can be bent almost as tight as a hairpin without kinking.Now with a 10 yr warranty. Defender has it for <$10/ft. It's only available in 1" and 1.5"...flex PVC #148 is ok for toilet intake line and the typical 5/8" vent line.

--Peggie

[rslifkin]

Originally Posted by peghall

flex PVC #148 is ok for toilet intake line and the typical 5/8" vent line.

Interestingly, my boat came to me with 148 for all of the sanitation hoses. The only one that was permeated was the vent. So I replaced it with a spare length of hose. 1.5 seasons and it's permeated again, but the rest of the lines aren't yet...

[Kupe]

Originally Posted by malbert73

Hi all-
Resurrecting this thread as I am about to install a new Ronco tank in my T40.
Any concerns about using schedule 80 PVC threaded fittings? I will be using PVC for some of plumbing leaving tank to prevent hose permeation issues over time.

Also, I read with great interest the "no sealant" recommendation on Ronco website. I want to follow their thoughts, and this makes me nervous. Others? (Peg, Thinwater?) Tape would maybe be harmless?

Hi- I was the OP of this thread and hope it provided some help. Ronco was a lifesaver for me after neither Tartan nor Kracor could help with a replacement tank for my T28.

I stuck strictly with Peg's and Kracor's advice and used exclusively Teflon plumbers tape. Have had zero issues.

On a related note, I went with Trident Sani Shield hose. Amazing bend radius without kinking and extra thick for permeation prevention.

Cheers!

Kupe

[Kupe]

Originally Posted by Kupe

I stuck strictly with Peg's and Kracor's advice and used exclusively Teflon plumbers tape...

Gahhh I meant to say I strictly followed Peg’s and Ronco’s (not Kracor’s) advice and used Teflon tape. The only advice Kracor offered was to don’t bother them with “little boat problems”. So glad I found Ronco!

[malbert73]

Originally Posted by peghall

PVC fittings not a problem...in fact, if the discharge fitting is at the bottom of the tank, it's a good idea to use PVC pipe to the top of the tank, then switch to hose the rest of the way.

Teflon tape, and plenty of it, is the ONLY sealant I recommend using on threaded tank fittings. Nothing but dishwashing liquid--or better yet, K-Y, on the barbed end.

Be careful not to over-tighten threaded fittings...they're NPT standard, which is slightly tapered--too slightly to see with the naked eye in a female fitting that short. Over-ightening will result in a cracked female collar, if not immediately sooner or later...I've seen it take a few months.
So just a quarter turn past hand tight is as tight as you want to make 'em.

If you haven't already bought hose, Raritan SaniFlex RaritanSaniFlex hose is the best choice. It's proven to be 100% odor permeation resistant and has the added advantage of being so flexible it can be bent almost as tight as a hairpin without kinking.Now with a 10 yr warranty. Defender has it for &lt;$10/ft. It's only available in 1" and 1.5"...flex PVC #148 is ok for toilet intake line and the typical 5/8" vent line.

--Peggie

Super helpful, thanks! Yes had my eye on the raritan saniflex. Easier to work with and odor resistant = no price too high since replacing head plumbing is way low on my list of preferred boat jobs.
.