Replace Holding Tank?

[davidwigler]

Peggy,

Last year after much help from you I replaced all the hoses with Trident. I replaced the 5/8" vent line with 1.5" Trident also. Pump out is so much easier now, but there is still some odor. The holding tank is located in the forward bilge, and unfortunately shares space with the reverse-cycle air conditioner so the odor is pumped into the cabin whenever heat or air is used.

There are no discernible leaks at any of the fittings or elsewhere on the tank, but the tank is slightly concave on the top. I'm assuming excess vacuum with the old vent line did that. I can't see any cracks, though.

I have washed the entire area carefully with a garden hose and sprayed KO all over the tank and bilge area. It helps for a while, but then the problem is back.

The 40 gallon tank is original, 20 years old, and has the discharge line at the bottom. I understand the new ones use a top-mounted discharge tube which is a much better system.

Can you think of anything else I should try before replacing the tank?

Thanks so much.

 

[Peggie Hall HeadMistress]

A couple of questions...

All Trident hoses are not created equal...which Trident hose did you use?

Did you wrap the threaded ends of the tank fittings with Teflon tape to ensure a good seal?

When you sprayed with K.O., did you make sure to get it into every nook and cranny in that locker, and also under the tank? And did you leave the area open, preferably with a fan going, so that plenty of fresh air could circulate for at least 24 hours?

I don't think you need to replace the tank...I think we just need to find the remaining source of odor you haven't found yet and eliminate it.

 

[davidwigler]

I used Trident 101 and double clamped the fittings but did not use teflon tape on the fittings.

I was surprised that the Trident hose fitted easily over the hose barbs. No heating or lubrication was needed.

Please tell us more about the teflon tape, i.e. how much to use, etc.

 

[davidwigler]

I read your post again and see you were talking about using teflon on the threaded fittings on the tank. I didn't remove those from the tank.

Wouldn't there be evidence of leakage if this was the problem?

Thanks

 

[Peggie Hall HeadMistress]

I think we may have found your problem

Hose shouldn't slip onto fittings easily...they need to be a tight fit--tighten enough to at least require lubrication, if not softening too--in order to get a good seal. So I suspect the hose connections may be the source of your odor. Apparently they're 1.25" barbed instead of 1.5"...which, if they're gray PVC, could be the result a PO's sanding the barbs down too much to get hoses onto 'em.

A sealant is NOT the solution! New fittings are the solution.

You asked if there'd be evidence of leaking around a fitting or hose connection. Maybe...maybe not. It's quite possible there'd be so little that you'd only discover it by wiping with a rag. Even if it's not actually leaking, odor could still escape. You can check that by wiping around each hose and fitting connection with a clean rag for each...smell the rag.

Btw...I forgot to ask: you said the tank is original...is it plastic or aluminum?

 

[davidwigler]

The tank is plastic and the fittings are white pvc, not grey. I assumed the hose barbs were 1.5" . The one I added for the vent line is definitely 1.5" and the Trident hose slipped easily over it too. Same for a new Jabsco toilet I installed at the same time.

I'll try the rag trick on the fittings. Thank again.

 

[Rick D]

Where is the macerator? If it is low, it might be the source of your odor.

 

[PKFK]

All Trident hoses are not created equal...which Trident hose did you use?

This has piqued my cusiosity....my boat has 5/8 ID reinforced vinyl hose for the vent (I know, 1.0 " is better !!).

However vinyl hose is not exactly odor-resistant, and I was thinking of replacing it with the series 148 5/8 hose listed here:
http://shop.sailboatowners.com/detail.htm?fno=400&group=1254&cat=1014
(This is on the page for series 101, but the line item says series 148)


But.....after reading Peggie's comment, I was wondering if this is acceptable ?

I see Trident has 101 and 102 type hose (and 148 on the 101 hose page) - I thought it was just a different color. Can you please expand a bit on your comment ?

Thank-you !

Paul

 

[Peggie Hall HeadMistress]

Trident or Shields #148 is fine for vent line

The sbo.com page is a bit confusing...it's not only the "101 page," it's the page which shows all the most commonly requested Trident hose. See the marine hose page on the Trident site here for the differences in their sanitation hoses.Trident Marine: Sanitation Hose

101 and 102 are the same hose except for color...the others are all different.

 

[PKFK]

Thank-you for the clarification.

BTW I have your book and it is an excellent practical reference !