How to regrind worn tap seat + How to properly install a new seat insert

Hi

I have/had leaking taps in the laundry, so I

1 - Used a manual seat grinding tool to grind the surface down to an even surface. I had to constanly unwind and take out the grinder to check on the progress.

Question: How do you know when the regrinding is successful? is it when a entire new ring of fresh brass is exposed? as opposed to just some areas of fresh brass.

2 - As i was unsure if i had correctly reground a flat seat surface i decided to install one of those stainless steel seat inserts from bunnings. This was achieved by rewinding the spindle back in with the old washer until the seat was forced home. Only problem is, when i looked closely it did not seem that the new seat was 100% up against the existing seat but slightly forward of it. No amount of forcing home with the spindle and now squashed washer would help. There was no leaks however i assume this was only due to the tapered body of the insert being hard up against the tap wall so no water could sneak through the gap between old seat and new seat.

Is this correct? How does one know he has installed the new seat correctly should it force in flat against the old seat surface? No doubt my spindle is now slightly further out in mm when Tap closed compared to the old seat.

Any images or weblinks welcome.
Cheers


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