03 August 2010

Flakey

Whilst nattering on about chisels and the such like, it might be worth mentioning a little encounter with one of my Ashley Isles chisels. Matthew from Workshop Heaven sent me a whole set of dovetail chisels, bar the 6mm size which was out of stock. This duly turned up a few weeks later and was without further ado honed and placed in the rack along with all the others.
I first picked it to use it a couple of weeks ago just to pare the corners of some ebony on the Media Unit handles, with the result that the edge instantly crumpled.

I didn't think much more about it, but simply re-honed it to grind back past the first mm or so of poor steel, which is often the case with a new blade.
I used it again on Sunday to pare some joints on much softer pine...and exactly the same thing happened, so I started to think I might have a 'duff' one.
I decided to grind back the blade by another mm on the Tormek, in effect turning the chisel into a miniature engineers scraper. I then re-honed it to 25 deg, which is the angle that all the others are honed at.

Then came the test.

Within 20 seconds of paring the same soft pine, the edge resembled a Cadbury's Flake but just to make sure that all the others were good, I repeated the test.

It looks like the 6mm chisel came from a suspect batch, so it's going back...

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