[Andrew Biggs]

Hi Jim

Here's my thoughts based on my experience (as little as it is)..............

You maybe forcing the graver a little bit hard and therefore casting a slight burr on the top edge. Let the graver do the work and put less pressure on the tool.

The graver maybe slightly dull and not cutting cleanly. Keep it sharp.

You maybe trying to cut too deep therefore forcing metal out and up. Try cutting a bit shallower.

Gety a bit of scrap metal and spend a few minutes making cuts trying out the above and see if it makes any difference.

Hope this helps a bit.

Cheers
Andrew Biggs