I bought a deburring tool
(http://www.screwfix.com/app/sfd/cat/pro.jsp?id=13315) and although there's
only one way it can work - shove it in the pipe, turn - I'm not getting
satisfactory results. The tool does shave off copper, but there is still a
burr. If I continue until there is no burr, I've removed so much copper that
the wall at the cut end of the pipe now tapers from the inside out and is
very thin. In other words the tool removes the 'good' wall of the pipe as
well as the burr.

What am I doing wrong? Is a slight residual burr to be expected when using
this tool? Should I try a different tool? I can file off burrs well enough
but it is time consuming.

If it makes any difference the pipe is standard 22mm copper and I am cutting
it with a Monument auto wheel cutter like this one
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=12380

Thanks

Pete