How Far Down Can I grind the seat with my reseating tool?

[abrogard]

Seems to be some flaws in the brass of this tap (faucet?). It has fine scribbly black lines crossing from the inner of the pipe to the outside. I guess that's why it still drips a bit even after a number of reseating attempts and many new different washers.
Is this something others have seen? It's a flaw in the casting or it's something that is kinda 'working' even now and will get worse?
How far down can I grind without creating bigger problems?

 

[Ben-gee]

You should be able to see how much brass is left in the seat, keep grinding.
Sometimes you will come across a crack or a void- grind through it , it will either disappear or the tap is scrap.

One alternative is that you can fit in a new seat , I think they are nylon, they are often an interference fit but a bit of epoxy to fill cracks in brass seat and help bond can be useful in some situations.

Usually replace the tap at this stage as it is often worn and untidy looking - but if it’s destructive to get to the back of the tap, or it’s a particular matching design to others then a reseat is what I do.

 

[abrogard]

well if I remember right the problem is the thing is not a detachable tap. The seat and all is in the pipework in the kitchen wall. Been months since I saw it but that's my memory. That's why its a problem.
I'm worried about buggering it up and then I need a plumber and a big job breaking into the wall etc...
So there are 'new seats' ? I better go to tradelink or somewhere, ask about them.
But also I could put some kind of epoxy down in there?
And then, I suppose, I run the reseating tool over it to make it a good seat?

 

[Ben-gee]

You can try epoxy on it’s own but it tends to get pushed out in my experience if you have high pressure.

I have repaired one with “chemical metal” before ( so sort of two-pack filler - I think it might be epoxy).
The trick is to open up any cuts to a “V” shape so that water pressure cannot push the wedge of filler out.
Like you say, once hard you resurface with the seating tool.

But look for replacement seat - it’s much easier!

 

[Chuck]

I have repaired one with “chemical metal” before ( so sort of two-pack filler - I think it might be epoxy).

Just a reminder for the OP, if they go down this route, to use a WRAS-approved product as some epoxy resins involve quite nasty chemicals.

 

[Ben-gee]

Never did me any harm… mind you that’s about the time the headaches started…and those voices in my head telling me to do unspeakable things…