Basin Waste and Piping and Not Aligned - Causing Weeping of Connectors

[Ben-gee]

We are now into the realms of skill/experience - you will learn from this and ultimately get a feeling of satisfaction, also perhaps an appreciation of the value of a good tradesman.

 

[Ben-gee]

In my experience the most likely source of this leak will be between the ceramic and the metal waste fitting itself.
The space between the threaded body of the waste and the ceramic “tube” it goes through must be sealed at the bottom. Assuming it is a slotted waste, this area will fill with water and you need to ensure it can’t seep out at the bottom. The rubber washer supplied is often inadequate for this purpose so most people seal the space using silicone or plumbers mait (putty). I prefer plumbers mait because i) it can be tested immediately and ii) it smells and feels as though you’re a proper old skool plumber!

 

[Clemenza]

Is there a rubber washer on the top of the trap where it fits to the chrome waste?
Is the bottom face of the waste flat and not corroded and if it's plastic not split?
Is the leak from the trap to waste connection from below the spigot nut or above, if above it can sometimes be the chrome waste (if it's not new) has corroded within the thinnest part of the thread and is leaking down and over the nut?

If after a couple of attempts the trap to waste still leaks, get some PTFE, roll it up like string and wrap a few turns just above the top edge of the washer, it'll push up into the bottom of the waste and provide a larger sealing surface.
In the past where the bottom of the chrome waste has corroded I've removed the washer and wrapped many turns of ptfe to create a large soft seal.

As BEN has said, the lower compression joint will normally seal with quite a noticeable misalignment.

Both the trap and waste are brand new and of good quality. No corrosion. I think I will try the layering of PTFE tape on the top of the spigot washer. I can access this area without removing the bottom compression fitting with watertight currently.

 

[Clemenza]

Both the trap and waste are brand new and of good quality. No corrosion. I think I will try the layering of PTFE tape on the top of the spigot washer. I can access this area without removing the bottom compression fitting with watertight currently.

Something is very wrong if you can't make that water tight.
That's not misalignment by any figment of imagination.

Get some new rubber seals. Make sure they are the correct ones

I used the PTFE layering technique snowhead suggested earlier today on the spigot joint. This sorted the problem instantly.

However, despite the leak on the compression joint being virtually sorted, I still detect very small isolated speckles of water, that show up on the blue tissue paper I use to test the area. Is there any equivalent techniques to bolster the watertight integrity of the compression joint.

 

[Ben-gee]

Just make the joint as I told you earlier. Do the nut up by hand , it should run freely and then resistance is felt- at that point give it say 1/4 turn more.
Test and if leaks then nip 1/16 turn and repeat.
The trick is do not over tighten.
This is what I’d was referring to as skill and experience- we just get it right first time by feel. But the above method will work if followed.

 

[Clemenza]

Just make the joint as I told you earlier. Do the nut up by hand , it should run freely and then resistance is felt- at that point give it say 1/4 turn more.
Test and if leaks then nip 1/16 turn and repeat.
The trick is do not over tighten.
This is what I’d was referring to as skill and experience- we just get it right first time by feel. But the above method will work if followed.

Ben-gee

All is fine now. Thanks for your kind advice, without which I would not have sorted the problem.