What is This ... A Vent Surely, But...?

[BlackOak]

I have this vent thing, near the holding tank. It runs from the holding area, to a little cap on deck. But the part in the holding tank area has no connecting thingy. See photos

[Vasco]

All holding tanks have vents. If yours is not connected to the tank you have a problem. The tank might be venting into the boat and if the tank's full might even leak into the boat. Does your boat stink?

[BlackOak]

Originally Posted by Vasco

All holding tanks have vents. If yours is not connected to the tank you have a problem. The tank might be venting into the boat and if the tank's full might even leak into the boat. Does your boat stink?

No my boat doesnt stink, yes my holding tank is vented out a different way, and it doesnt leak. Now the question was, if this is a venting tube, then how would I connect to it?

[Vasco]

If your holding tank is already vented, and the vent is working then it's fine. Hard to tell from the pics what's what. Holding tank vents are normally hose, not abs or whatever the white pipe is. When your deck's awash does water run into the boat through this pipe? Is this pipe fwd or aft? Big enough to run chain down into the bottom of the boat?

[HappyMdRSailor]

Looks like an old venting line... If you have one, and it works just leave it... cap the exterior...

[BlackOak]

Actually its all copper, the white part is painted copper, the PO painted it for some reason. The copper tubing/pipe is 3/8 od. The vent is amidship portside deck, and it has never leaked water.

[HappyMdRSailor]

3/8 copper ain't a vent line... Or a very baddddd attempt at one!

[David M]

Copper pipe would work, it's just not normally done for a holding tank vent line. Hose is easier to run. You would want to use sanitation hose which sewage smell cannot penetrate. The holding tank vent line does need to be run to the outside of the boat, for obvious reasons.

[cal40john]

Maybe it was an attempt at venting the compartment. Many holding tank installations don't smell good for one reason or another, so maybe his solution was to try to get the smell vented outside rather than concentrate and get into the rest of the cabin.

Just a guess.

As far as running copper pipe, if he was willing to deal with the installation hassle once it seems like a good choice over no matter how ridiculously expensive sewage hose you buy you will be doing the job over and over as it permeates with the smell.

[BlackOak]

I inspected it again today. The way it is run, it looks factory installed, and since I dont know my metals, its possible it could be brass. Its difficult to find much info on a Seafarer sailboat, I mean the small details of one. I havent found one yet, similiar to mine.

[rognvald]

BlackOak, from you photo(s) it appears that the unconnected vent line was probably original equipment in your boat and the copper(?) was added by its owner at a later date. It is unclear from your photo where the unconnected line is routed and what material was used initially. As another respondant has mentioned, its not that the copper/brass(?) is necessarily bad, but a much simpler/cleaner installation could be accomplished with sanitary hose while maintaining the existing terminal fittings. The use of a sanitary hose allows periodic inspection, cleaning and replacement when its life is exhausted and would allow flexing at the terminal connections when the boat is vibrating under power or rolling in a seaway. The unused original fitting can be maintained as an added vent in the compartment as long as water cannot be shipped below to any degree. Hope this gives you another perspective. Good luck and good sailing.

[perchance]

If the boat has/had an internal fuel tank it may be the vent line for it.

[BlackOak]

The photos are in order, starts under the salon bench nearest to the Head (the holding tank in under that salon bench), then into the head thru the wall, along the wall, to the hull, then up to the deck. The first and second photo, is where it starts, but I see no fitting, just what you see in the photo. I would suspect there should be some kind of a connector, its weird. Weird boat..but its mine..lol

[Pelagic]

I tend to agree with rognvald’s assessment.

Maybe the original installation did not work well and a PO installed a new one. If it is not connected then it is doing nothing and can be removed and the deck sealed.

[endoftheroad]

I've seen a deck recessed anchor locker drain using copper tubing or the like.