Putty/caulk that will seal in presence of diesel

RalphVa · Sep 30, 2013

This isn't directly related to tractors, but the solution could be if someone has a tiny diesel leak to fix.

I refilled the 60 gallon belly tank on our Isuzu diesel generator last week. Today, I noticed some diesel had leaked out. The fuel level had gone down in the standpipe to down near where it is threaded into the tank.

Has anyone found a putt/caulk that would seal in the presence of diesel? Not easy to get to the standpipe or the fuel level indicator to unscrew them, prep and to screw them back in, as the outer housing is in the way, and the doorway looking into there doesn't go down far enough to easily get to these.

Ralph

Recoveryhill · Oct 1, 2013

From your description I'm having a difficult time visualizing your setup. If you can't get to the pipe to unscrew it and it is hard to get to to, how are you going to seal?

If you could get to the joint that is leaking, here's what I would do. Drain off sufficient fuel to get the level below the leak, clean the surfaces free of any residual oil using alcohol and put a bead of JB Weld around the pipe joint. This would come under the heading of "field repair", "temporary fix", what have you. Anything that has been screwed in can be screwed out, sometimes you have to disassemble some stuff that may be in the way.

Good luck and some photos would help.

Ken · Oct 1, 2013

Goop brand has a epoxy that is advertised as to seal any thing to anything.

I have used this on a puncher leak in 5 gal plastic container. so far has held so some what flexable material.

Is this tank between the frame of the Generator?

metal crack or seepage from rust. if where a weld had been made a application of any epoxy would hold since no real pressure.
ken

gwdixon · Oct 1, 2013

Try going to a knowledgeable and experienced auto parts store with a machine shop. (ie. not O'Rielly, etc.)

Ask this same original question to an older counter guy that is dirty.

That is what I did and he directed me to the perfect sealer. Wish I could remember the name of it but it worked for a situation very similar to yours. Still holding after about three years.

Soundguy · Oct 1, 2013

plenty of people make 'gas tank repair epoxy sticks'

clean the metal off.. right when you mix the stick and apply.

most state they will stick to gas/oil wet metal and claim they are ok for gas tanks and oil pans.

dragoneggs · Oct 1, 2013

Ralph, I PM'd you.

RalphVa · Oct 1, 2013

Think I've figured it out. There's a right angle vent among the connections. Think it is probably the source of the seep; I'm thinking it has a one way check valve in it that sucks in air but is supposed to stop fuel from coming out. I'll have to get a piece of 5/16" tygon tubing to attach to it to act as a level gauge to see the fuel when it rises up into the filler neck. Then pump some diesel back out to get to just below the filler neck and vent elevation.

The tank has one of those float fuel gauges, but you cannot see the thing with the acoustic housing in place.

Ralph

Raspy · Oct 5, 2013

Coal Tar epoxy is commonly used in or on iron fuel tanks on boats. Might be just the thing for you.

GYPSY · Oct 6, 2013

self tapping screw with a rubber washer has done the trick for years on leaky gas/diesel/fuel tanks. its got a hole in it anyways so a little screw wont hurt, when your empty at some point, do an epoxy fix. easy.