holding tank pumpout fitting

[jazzzman]

Good Morning:
Does anyone know the size and tread of the bronze holding tank pump out fittings for a 36 aftcabin? I cannot find any pump out station with an adapter that fits our tread.

[jleonard]

Yes I know what you mean. When I bought my boat the previous owners had their own fitting, and I use that fitting when it's pumpout time if the poo poo boat doesn't have the cone sucker fitting.
I'll try to remember to bring it home for next week and measure the threads and advise.

[jazzzman]

Thank You, I'll look for your information. D

[mike66]

I'm in the process of replacing my holding tank, so will change my deck fitting out to standard size while I'm replacing hoses anyway. Newport pumpout guy told me I have metric threads. We just got back from a fun weekend in BI but had to put up with a leaking holding tank. I hope the smell will go away. Keep you posted on the project.

[DougSea]

I'm in the process of replacing my holding tank, so will change my deck fitting out to standard size while I'm replacing hoses anyway. Newport pumpout guy told me I have metric threads. We just got back from a fun weekend in BI but had to put up with a leaking holding tank. I hope the smell will go away. Keep you posted on the project.

I tried the "Starbrite Boat Bomb Deodorizer", which I picked up at West Marine. Did a good job of eliminating some "lingering remnants" of my head re-plumbing project.

http://www.westmarine.com/webapp/wcs/st ... sNum=10381

[mike66]

Thanks for the info! I don't think sanitation work is for me, although I managed to get 75% of the old system out today. It was a rusty macerator and deoderizer injector setup that was past its prime. The boat has vacuflush that was installed fairly recently, the tank and discharge hoses were shot. This system had a 5/8" hose leading to the pump-out hose using an adapter. It held about 12 gal. It looks like it was meant to treat and discharge in the days before that became a no-no in many areas. The original holding tank is under the gally, but was decomissoned for some reason. I suppose I could pressure test it, but I'll be happy with the new 25gal Sealand I got from Defender.

[DougSea]

Hey Mike, if the vacu-flush is set up like mine it's really just a holding tank with both pumpout and discharge options. Handy to have if you go outside the 3 mile line, just don't forget to secure the closed thru-hull when inside the line. (I have mine double tie wrapped). The vacuflush uses the smaller "vacuum generator" to flush the head and then pumps the waste into the separate holding tank.

All this head talk has me thinking I need to write up my plumbing adventures...

[mike66]

Sorry to hijack your thread. I have my old deck fitting out, but haven't checked the thread size yet. I'll try to do it next week when we get back from BI with hopefully this time an oder-free boat. My Vacu-flush has the vac generator which then discharges into a tank. The prev. setup had the vent hose running down into the bilge in a long loop before heading up to the vent. I'm sure it was full and blocking the air flow. The deck fitting had about a 2" hose. Replaced it with the standard 11/2" so hopefully the pumpout guys will be happy. Haven't set up the macerator yet, but at least we're up and running.

[jleonard]

Oh sugar, I forgot to take the fitting home with me. Will try again next week. Jay

[jleonard]

The good news is that I have the fitting with me. After some quick measurements I am not 100% sure what thread it is.
I need to take it home today and clean it up with a wire wheel (then some bleachwater) and bring it back to work and try some thread pitch gages on it.
Stay tuned....

[jleonard]

IMGP8213.JPG

Here's a picture of my pumpout fitting.
It looks like the PO cut a pipe that had the proper thread and pressed it into the standard to make this adapter.
We measured the thread and it apprears to be a non standard.
It could be a 1 13/16 - 16 UN thread, but the OD is a little small, however my SWAG as an enigneer says this would fit fine. (my adapter measures 1.770 on the major OD, specs call for 1.801 as a min for major OD)

Be aware that this is a straight thread and you will need a lip and an O ring so it can seal.
PS If you have one of these made have the shank of the adapter made 3/4 inch longer than you see here. The pumpout guys often bang theoir knuckles on the deck when clamping up to mine.

[DougSea]

Pardon my ignorance...but wouldn't it be easier and cheaper to just fit a new deck plate with a standard thread?

[jleonard]

Probably not as that would entail some work on a boat with teak decks.
However that's an option for sure.

[mike66]

Doug, on my 40 that's what I did. Luckily the underside of the fitting is easy to reach, and removal was not as bad as I thought. The factory hose is way larger than 11/2" so that involves alot of sweaty pulling and coaxing to get out and replace with standard. If the rest of the system is OK then an adapter makes sense. If anyone needs a deck fitting to take to a shop to make an adapter, let me know.

[mike66]

Just a follow up on completed project and I know this wasn't the OP intent, but replaced Jabsco impeller and screwed macerator pump into fitting on Sealand holding tank. Connected to through-hull with 1" sanitation hose. Now completely new deck fitting and hose 1 1/2" , vent 5/8", holding tank 25 gal and macerator. Fit very easily starboard side against the fuel tank forward of the engine and gen. One system redone and ?? to go.