When are vented loops required?

[bobmcd625]

I managed (with quite a bit of muscle power) to get all Trident hoses installed except the link between the two way valve and the deck pump out fitting. That is very short and needs a more flexible hose. I'll look into the Raritan Sani-Flex recommended by Hop-Car.
One (hopefully) final question: What type of thru-hull fitting should I use for the atmospheric vent from the holding tank? What I have now must be aluminum since it is badly corroded. Also, should I have a filter in that line? I see that recommended in some articles. Almost done. Thanks to every one.
Bob

[HopCar]

Assuming your hull is fiberglass, just use a regular bronze, chrome plated bronze or stainless thru-hull for hose.

Unless you go to a lot of trouble to change it, you're stuck with the size of the fitting on your tank, probably 5/8". Larger would be better if you can. Don't use the vent fittings sold for fuel tanks. They restrict the vent to smaller than the 5/8" hose.

[peghall]

What type of thru-hull fitting should I use for the atmospheric vent from the holding tank?

Do NOT use a "vent" thru-hull..they're actually designed for fuel tank vents, but boat builders use the same thing on all vent lines. What you need is an open "bulkhead" or "mushroom" thru-hull--the kind you can stick your finger into...any material except nylon.

NOOOO to the vent filter...it actually helps to create the problem it's sold to solve (why couldn't I have invented something that does that???) by impeding the exchange of air needed to keep the tank aerobic, which is essential to PREVENTING odor instead of trying to deal with after it's created.

If you're in the mood to read, you might consider checking out the link in my signature.

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

http://www.amazon.com/New-Get-Rid-Bo...dp/1892399784/

[bobmcd625]

Got it! (Again!) I did buy your book, Peggie, but just have not taken the time to absorb it all. Now have read the interesting chapter about the venting issue. I don't have a filter and had not thought about it, but when searching for the thru hull fitting found several sources which recommend a filter in the tank vent line. Your explanation makes more sense.
Thanks again to PegHall and HopCar!

[bobmcd625]

So...I did read Peggie's good book and have a question about bio additives: What do you think of Pure Oceans Bio Odor. It seems to do the same as the Raritan product you mention. I found a bottle of this on the boat when I bought the boat, but have not used it yet. Now would be the ideal time to introduce such a bio product with a very clean tank and new hoses.
And another (final) item: I am about to install the deck pump out fitting. I was going to drill through the deck and use machine screws with washers and nuts on the inside. I now realize that the deck is thick glass and has a wood core (not sure what type) so now think that maybe screws into the deck would be better since that would avoid three holes through the deck. Of course I'll use a good bedding compound to seal it all off. Thoughts? Suggestions?
Thanks again.

[peghall]

What do you think of Pure Oceans Bio Odor. It seems to do the same as the Raritan product you mention. I found a bottle of this on the boat when I bought the boat, but have not used it yet. Now would be the ideal time to introduce such a bio product with a very clean tank and new hoses.

Raritan K.O. is part of the product line that my company sold to Raritan in 1999. It was the first bio-active (live bacteria) holding tank product and has spawned a whole bunch of "me too" products since we introduced it in 1987. The Pure Oceans product appears to be another one. How good it is depends on the number bacteria colonies per gallon...the more there are, the better, and the more expensive that makes it. So the odds are pretty good that any substantially cheaper version skimps on the bacteria. I hadn't heard of Pure Oceans till you mentioned it, so it doesn't seem to have much of a market share, but that doesn't mean it's not any good. However...you found it on the boat, so we don't know how old it is. Live bacteria products have about a 2 year max shelf life, plus they're temperature sensitive--especially to heat. So if it's older than that and/or the boat had been sitting in the hot sun, it's toast.

Non-toxic tank products have evolved a bit in the 30 years since we introduced K.O. and there's one that's catching on all over and everyone who's tried it is raving about it: NoFlex Digestor Noflex Digestor, And it's sold everywhere....google it for the most convenient dealer. So that's what I'd try first.

As for your deck pumpout fitting... You don't need through bolts and nuts...it's not a cleat, it won't have any stress on it. Just use screws, making sure they're long enough and the fitting is properly bedded.

Btw...feel free to give me a shout via email any time...I'm always glad to help.

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein
http://www.amazon.com/New-Get-Rid-Bo...dp/1892399784/

[bobmcd625]

Thanks, Peggie. I might as well start out with the newest, No Flex Digestor.
And will start with long screws on the deck fitting. I was a bit worried about the possible abuse from pump out people not being too careful with their big "sucker".
Getting close to completion....
Cheers

[rgleason]

I would add to Peggy's note that any deck fitting drilled through balsa core should be reemed out and filled with epoxy or polyester paste to be made watertight and prevent rot. Do a search for more complete description in forum.

[bobmcd625]

Yes, indeed. Good point. Thanks!

[bobmcd625]

Hold on! What you say about sealing with epoxy should, I guess, apply to the large (2" dia.) hole for the pump out fitting, not just for the three smaller bolt holes. I'll have to get a larger round saw for that hole. I had intended to use a 2 1/4" dia hole saw. Guess I should go to 2 1/2". I will, of course, put bedding compound (4200) around all the holes on the deck before pushing the fitting into place and bolting it down.

[Cheechako]

Originally Posted by bobmcd625

Hold on! What you say about sealing with epoxy should, I guess, apply to the large (2" dia.) hole for the pump out fitting, not just for the three smaller bolt holes. I'll have to get a larger round saw for that hole. I had intended to use a 2 1/4" dia hole saw. Guess I should go to 2 1/2". I will, of course, put bedding compound (4200) around all the holes on the deck before pushing the fitting into place and bolting it down.

You don't need too big a hole, just gouge out the core after hole sawing, but leave the fiberglass! I have often just used 5200 to fill the gap instead of epoxy, I trust something with a bit of flex as well as anything brittle like thick epoxy resin.

[bobmcd625]

Originally Posted by Cheechako

You don't need too big a hole, just gouge out the core after hole sawing, but leave the fiberglass! I have often just used 5200 to fill the gap instead of epoxy, I trust something with a bit of flex as well as anything brittle like thick epoxy resin.

Got it. Use the 2 1/4" saw but remove more of the core, then replace that material with a good compound. 4200 should do. What about using butyl tape around the bolts? I saw that on a YouTube video. Looks smart.
Thanks for these tips
Bob

[rgleason]

I use an 1/8" or 3/16" allen wrench in a drill chuck to remove the core. I would strongly suggest using epoxy brushed heavily into the core area, then using thickened epoxy to seal up the core and fill the gap. I usually tape the opening from the bottom with duct tape, then force the thickened epoxy into the gap. Let it set up and then re drill or bore the opening again.

[bobmcd625]

Originally Posted by rgleason

I use an 1/8" or 3/16" allen wrench in a drill chuck to remove the core. I would strongly suggest using epoxy brushed heavily into the core area, then using thickened epoxy to seal up the core and fill the gap. I usually tape the opening from the bottom with duct tape, then force the thickened epoxy into the gap. Let it set up and then re drill or bore the opening again.

Sounds like a sound plan. This morning I drilled the 2 1/4" hole for the deck pumpout fitting as well as the three bolt holes. I decided to bolt through the deck. Now to do the epoxy sealing as you describe. Can you suggest which epoxy product to use?
Thanks for the good advice.