Tank vents

melp64 · June 30, 2024, 06:23:54 PM

I had a couple of people that have been refitting their boats ask to come aboard my boat as they have seen me out almost every weekend working on my boat. When they came aboard they asked why I tore out all the countertops and why the bulkhead rotted so bad. I explained to them about the vent in the stanchions on both sides, how they leaked down the small bulkheads and then under the countertops and bulkheads. One of them asked why I didn't plug and patch the hole and put in a side vent and showed me a couple of other boats that had these small vents on the side of the boat. Has anyone on this forum ever done that, and would it be a good Idea. I googled a picture of one of what they showed me

Stu Jackson · June 30, 2024, 06:48:25 PM

The downside of those vents is they seem to accumulate mud dauber nests and clog easily.

After owning my boat for 25+ years now, and reading everything (and writing a few), I have begun to suspect that the "fault" of the vented stanchions has never been a leak at the deck to stanchion base, but rather the hose clamp becoming loose where the vent line connects to the base of the stanchion. Water gets in the hole in the stanchion and as it passes into the hose, the loose connection, which has no barbs, allows slow leaks. I have no conclusive proof of this theory of mine, just popped into my head in looking at this post.

My port side is still pristine over the nav station, some evidence of leakage on starboard over the forward end of the dish storage in the galley. Both of those vents are actually within the wooden boxes just forward of ash battens. anything further aft would have be coming from leaking fixed portlights.

robbjd · June 30, 2024, 06:51:33 PM

On the Mk2, the vent for the holding tank was in the port side stanchion located above and outboard the electrical panel. Luckily one of her previous owners replaced the holding tank, and moved the vent forward and to the side of the boat. I think the stanchion vents were a bad idea, and their location a terrible idea. After all the work you've done new vents would be a great idea.

Noah · June 30, 2024, 07:06:52 PM

In my opinion the leaks at the stanchions have nothing to do with there being vents in them. It is caused by old bedding, a lack of backing plates and people pulling and pushing on them when docking. Ok, a rare instance if loose hose clamps, too.

I am not saying the vents are sufficient to do their job. The tanks, especially the holding tank could be better vented, but that is not generally the cause for water leaking into the boat.

Jon W · June 30, 2024, 08:48:45 PM

My 2 cents - Do yourself a favor and rebed all of your lifeline stantions with Bed-It-Butyl tape (if you can still get it). One at a time remove your stantions, clean the bottom of the stantion and the deck surface with acetone making sure all of the old sealant is gone. Check the deck core and seal it so water can't be absorbed into it. Then put a slight countersink in the holes in the deck surface for the butyl tape to form a gasket in. Add backing plates from the inside, put it all back together, tighten the bolts/screws snug then wait a day. On the second day do a final torque of bolts/screws. I haven't had a leak in 9 years. Good luck. YBYC

KWKloeber · June 30, 2024, 10:01:54 PM

Dan

I am confused.
Making no statement of the benefit of a larger vent, if the leak/damage was from the stanchion fasteners, then it makes no difference whether they are vented or not. It has to do with maintenance (negligence thereof) of the base seals.

If the leak/damage was from the stanchion vent itself (e.g., a loose hose clamp?) then it has to do with maintenance (negligence thereof) of the vent hose.

Jim Hardesty · July 01, 2024, 03:59:54 AM

Vents, vented stanchions and rebeding have been well covered here. Anyone needing a nights reading on the subjects only has to do a search.

One additional thing about the stanchions I'd like to bring up again, get rid of the fender washers. Call Garhauer and get proper backing plates. Need to call, they were easily available but not in online catalog and I believe fairly priced. Don't forget to order ones with the big hole for the vent tube where needed.
Jim

Ron Hill · July 01, 2024, 09:38:39 AM

Guys : The problem with the C34 vented stanchions is the LACK of Backing Plates!!!.

The contributing factor is that those 2 stanchions are at the widest portion of the hull and "helpers" on the dock tend to fend off by pushing on those stanchions!!!

Just contact Garhauer and get two backing plates and as mentioned bed them in with butyl rubber!!

a few thoughts

melp64 · July 01, 2024, 06:47:45 PM

I'm not sure if it was a loose hose clamp or if it was leaking from the deck under the stanchions or PO negligence.But it happened on both sides of the boat. The galley tops were mush and I had to replace the two small bulkheads because they were totally rotten and the bulkhead in the head I cut the bottom of and replaced I wondering if install the new vent and I epoxy shut the old hole from the stanchion, reinstall the stanchion with the backing plate wouldn't that eliminate one more chance for it to leak?

Noah · July 01, 2024, 06:59:13 PM

Again, the vent is not the problem.

Ted Pounds · July 05, 2024, 06:47:12 AM

Quote from: Ron Hill on July 01, 2024, 09:38:39 AMGuys : The problem with the C34 vented stanchions is the LACK of Backing Plates!!!.

The contributing factor is that those 2 stanchions are at the widest portion of the hull and "helpers" on the dock tend to fend off by pushing on those stanchions!!!

Just contact Garhauer and get two backing plates and as mentioned bed them in with butyl rubber!!

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ THIS! ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I made my own backing plates out of aluminum bar stock. The key is to spread the load underneath the deck.... My guess is that the Garhauer plates would do that even better than my homemade ones. Probably money well spent.

a few thoughts

Ron Hill · July 05, 2024, 09:52:03 AM

Guys : I don't recall the exact cost $? of the 2 vented stainless backing plates, but it was nominal and SOLVED the Problem!!!

A thought

Noah · July 05, 2024, 10:02:36 AM

https://www.catalinadirect.com/shop-by-boat/capri-26/lifelines-stanchions/stanchion-backing-plate-trapezoidal-all-years/?SearchResults=1

LogoFreak · July 16, 2024, 07:39:09 PM

Get rid of the stanchion vents, they're a pita and don't work well. Vent your holding tank thru the side of the hull with a couple of 1" thru hulls and put some scoops over them.

Ron Hill · July 17, 2024, 09:48:05 AM

Guys : Regardless of where the tank vent is you still need backing plates on those stanchions - because people on the dock still fend off by pushing on the top of those stanchions.

With out backing plates the seal (to deck) WILL break and water will seep down into the area below and rot out the wood!!

A few thoughts