I have a clogged tank vent. The only part of the vent I can get to
without major surgery is the external fitting, and that only from the
outside. As far as I can tell probing with a wire, it's clear. The
tubing and the tank fitting are completely inaccessible. Any ideas
other than adding a new vent?



On Thu, 24 May 2007 09:59:25 -0500, Peggie Hall
wrote:

It may not be clogged, it may just be a blocked tank vent that's
pressurized the tank,

wrote:

I have a clogged tank vent. The only part of the vent I can get to
without major surgery is the external fitting, and that only from the
outside. As far as I can tell probing with a wire, it's clear. The
tubing and the tank fitting are completely inaccessible. Any ideas
other than adding a new vent?

If you can't get to the tank to clean out the fitting, how are you gonna
add a new vent?

Try blowing compressed air down the vent line from the thru-hull. That
may knock whatever's blocking it into the tank. Do it in short
bursts...you don't want to blow out the vent line if the blockage
doesn't want to move. If that doesn't work, try putting some water down
the line--under enough pressure to get it all the way to the tank (or
the clog if it's further up the line)--in the hope that'll soften up the
stuff that's clogging it enough to blow it out.

If THAT doesn't work, I'm aftraid you're in for some major surgery to
gain access to the tank so you can remove the vent line from the tank
and scrape out the line and the fitting. You should prob'ly make that a
winter project anyway, 'cuz sooner or later you will have to replace all
the hoses.

To prevent a future vent blockage, backflush the vent every time you
pump out and/or wash the boat. And as long as we're discussing tank
maintenance, flush ALL the sludge out of it a couple of times a year,
and especially in preparation to winterize. Sludge left in the tank
turns into "concrete" that nothing will dissolve that won't also damage
the tank.
--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/boat_odors/