Turning

Subject:
Re: Questions on CBN/Alternative grinding wheels

Reed Gray
I did a test some years back on a wheel that was maybe 5 years old and pretty much wouldn't cut any more, but it did polish things nicely. I took aluminum, brass, copper, and a soft iron to the wheel and it left visible lines on the wheel. You can feel the wheel 'bumping' when stuff starts to load up on the surface. It took about a month for all visible traces to be gone. I apply a little lapping fluid to the wheel and sharpen scrapers on it. They will peel just about anything off of the wheel. There are abrasive 'cleaning' sticks that some offer. My first CBN wheels were a matrix bonded to an aluminum hub. The makers used a very hard white aluminum oxide wheel to true them up. I did try that onto my wheels and it does clean them up and it is harder than the CBN, but it puts a lot of aluminum oxide dust into the air. Nasty stuff. I wouldn't make a habit of grinding softer metals on a CBN wheel, but you can do it. Some lapping fluid would help keep it from loading up.

I seldom use my 80 grit wheel. I really couldn't tell much difference between it and the 180. Both left a nice burr on my scrapers. I do get a slightly cleaner cut with using my gouges with the finer edge. I have a 600 wheel that I only use for fine finish cuts and skew chisels. The finer grit edge just doesn't wear as well as the coarser grit edge. The fine edge is not good for heavy roughing.

robo hippy

© 1998 - 2017 by Ellis Walentine. All rights reserved.
No parts of this web site may be reproduced in any form or by
any means without the written permission of the publisher.

WOODCENTRAL, P.O. BOX 493, SPRINGTOWN, PA 18081