How do I sharpen wood lathe tools?
Be very careful with the grinder. It is only used to establish the original critical angle and to take out nicks in the cutting edge. If you use too heavy a pass and the metal changes color (metal temper color - extremely light straw, you've started to mess up - blue or dull metal color, you've really messed up), you soften the metal and it won't keep an edge till retempered or ground past the area where the coloration occurred.

Once the angle is established, you use standard sharpening stones to keep the edge, they are much finer grit and establish a really sharp edge. On a properly maintained tool with an established angle, this part is a touch-up process, not a laborious grind, and may be done several times during a turning session if maintaining a really sharp edge is necessary.

After fine stone work, you can use a strop charged with buffing compound to remove the burr (wire edge) that results from a good sharpening session. I also just used the buffing wheel on the other grinder (always use the portion of the wheel where the surface is passing away from you so the point doesn't catch and throw the tool at you).