glue for repairing air leak in pvc pipe

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by good_improvement, Oct 6, 2004.

  1. good_improvement

    good_improvement New Member

    What is the best glue for repairing slight smell at joint of large diameter pvc pipe.
    It is a dry joint in the pipe, so I think the leak must be on the top of a horizontal portion of 90 degree juncture. So waste water must flow under the leak. Think I feel a slightly cold air at the juncture.

    I have pvc primer and glue. But do not understand how this would work on an already sealed pipe. The pipe has been there for 10 years. How can I get this to fill the gap that I assume must be present. I do not want to damage the seal that is there. WOuld this risk damaging the seal that is there if I put it on the joint. Best procedure?

    I also have Devcon Plastic Welder 2 part glue. That has more body that could fill the gap.
    What type of glue is this. Would it work well for this?

    Finally I have Silicone RTV. Does it stick well to PVC? Does it leave a residue that if I removed it would inhibit other glues from working, if I did not feel it worked well enough.

    Once again there is no water leak, just a smell.

  2. Terry

    Terry Administrator Staff Member

    Bothell, Washington
    If it's a dry joint, it should be replaced. There are replacement couplings that allow you to cut the fitting out and replace it in-line.
    Trying to seal the dry joint will be a waste of time. :confused:
  3. good_improvement

    good_improvement New Member

    By dry do you mean the water flows through it , but does not stand in it.

    It is very hard to replace the joint as the horizontal pipe that comes into it, comes out
    from behind a wall. The exposed old pipe has essentially maybe a 1/4 inch space before it goes behind the wall. And the vertical pipe goes into the concrete (I also detect an slight odor there, but do not know if that is from the cold air from the 90 degree bend 3 feet above falling there and accumulating the smell) (I hope). Thoughts? Both pipes are right up against the concrete wall. It looks like very little play to make the joint as the vertical is in the concrete.

    I imagine you are talking about fixing it with a longer 90 fitting right, cut out the shorter and put in a longer oversized one to make up for the pipe removed?

    Even though glue is a waste of time, can you tell me the best type to try?

    PS. What is that yellowish stuff they wipe on seal the round access ports to the vertical pvc pipes?

    Once again no water leaks.
    Last edited: Oct 6, 2004
  4. hj

    hj Moderator & Master Plumber Staff Member

    Cave Creek, Arizona

    I think you may be imagining things. Even if the joint had been assembled without any glue, it would be tight enough so that you would neither smell any odor or feel a cold draft. If it was made so poorly that you could feel the draft and smell the odor, there is no way it could not leak whenever water flowed through the pipe, whether the water was on the top or bottom.
  5. good_improvement

    good_improvement New Member

    Yeh, I was wonder if I was imagining the smell myself.
    So I went to other similar pipes in the basement and smelled the junctures too, and I could not smell a thing. I agree, I do not understand how there could be zero water leak, even if it was on the top side of the juncture. Could it come out of the soil where it enters into the concrete (the concrete sort of covers 1/2 of the vertical coupling then there is a slight space.) Does the smell rise. or fall? The smell at the floor juncture is less than at the 90 degree elbow 3 feet above.

    Are there leak bubble tests?
  6. good_improvement

    good_improvement New Member

    I might be imagining the slight draft from the pipe itself, but no way am I imagining the slight smell if I get withing 2 inches of the juncture. So that would indicate that it is a very tight and almost completely sealed pipe which would explain no water leak.

    Oh well.
  7. PEW

    PEW DIY Senior Member

    Just a thought, NOT a recommended repair! Why not cover the joint with duct tape and see if you still have the smell, you may just find the smell is coming from elsewhere.
  8. good_improvement

    good_improvement New Member

    I did not put tape around it because the back side of the juncture is pressed flush with the concrete wall. And to the the one side as I said before, it comes out of a wall. Also, I did not want to mess up the plastic by leaving sticky tape residue behind which is hard to clean off. Maybe I will try so painters tape on the front side of the joint, then try to wedge it into the thing towards the back to make a little seal for the front portion. If it is in the front and top or bottom, then okay I learned where the leak is. I guess it is just easier to dribble some glue in the back side of the joint than to make a seal with tape.
Similar Threads: glue repairing
Forum Title Date
Plumbing Forum, Professional & DIY Advice Would a tailpiece be glued into waste line? Dec 11, 2014
Plumbing Forum, Professional & DIY Advice Can I remove glue and primer from pvc? Aug 4, 2014
Plumbing Forum, Professional & DIY Advice Stop me before I glue this up Nov 14, 2013
Plumbing Forum, Professional & DIY Advice slow set pvc cement or glue for slip fitting vs. fernco or no hubs Jan 10, 2013
Plumbing Forum, Professional & DIY Advice Threaded vs Glued PVC floor drain pipe in cabinet bottom Dec 2, 2012

Share This Page