On Sun, 28 Jan 2007 16:29:01 +0000, ClassA wrote:

I have a tap that is dripping and I have looked at it and seen that the
seat needs to be dressed. I have a tap re-seating tool, and when I used
it in the past I ended up calling a plumber. He dressed the seat but
after a couple of years it needs to be done again. The re-seating tool
that I have is cheap and nasty (like this
http://www.toolstation.com/search.html?searchstr=69230 - the cutters
have saw-tooth cutting edges like a router), and I am tempted to get a
better one, but when I remember the problems I had before I am not sure
that a better one will overcome them. My problems we-

1) The tool had a tapered thread that wouldn't engage very positively in
the tap thread, so I could never be very sure it was installed
perpendicular to the tap seat. Some of the tools available have a
parallel thread, but I don't know how to know what thread size I need to
fit my tap. How do I measure it?

2) The worse problem was that when I turned the tool it did not turn
smoothly, but chattered, so that I ended up with a seat with a wavy
surface. I think chatter is a known metal-working problem associated
with cutting brass, so nothing new there. I've found a couple of guides
on the Internet about using a re-seating tool, and they say 'turn the
tool smoothly', and that is just the thing I couldn't do!

Any comments or advice would be very welcome.

The parallel thread version is made by Monument (I think) and is available
from screwfix.
These tools are quite hard on the heel of your hand, firm pressure and
twisting is not easy.
If the result is clean and shiny that's good enough. Perhaps you were
doing it too hard or the tool was not held really square to the seat.




--
Ed Sirett - Property maintainer and registered gas fitter.
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