Beginner: Spindle and bowl gouge grinding angles question.

[Paul Hannaby]

EDIT: Notice the bluing on the tool. I have a wide 6" white grinding disc, bought 20 years ago. Videos of people grinding turning tools show them grinding for several seconds but not apparently getting bluing. Is bluing to be avoided with HSS, and if so, how. I press very lightly.

I think you have ground too long a point on the gouge and the edge profile has ended up (looking at it from the side) concave. I would grind the point back until the edge profile looks convex. It will make the tool easier to use.
Have you tried dressing the wheel? If not, try that to reduce bluing. A properly dressed wheel will cut faster and cooler than one that has been used for a while and has become impregnated with metal fragments. You can use a carborundum stick (devil stone) to dress the wheel but even better would be a diamond matrix.

[Stevekir]

fuzzyturns:

25 degrees was a mistake, but I am pleased that I am getting on with it well. I will regrind to 40 degrees. Also, I can see the need to grind the heel.

Paul Hannaby:

Having a convex profile is interesting. I can see that would be helpful. On dressing the wheel, I bought a diamond dresser from Axminster and used it recently for the first time. The wheel was indeed rather black.

[Derek]

When i started I found Brian Clifford's pages very useful HERE is the sharpening jigs from there

[Stevekir]

Derek:

Thanks. I have saved this. I was amused by "...it comes out at 469 KB, so it takes a couple of minutes to download." It downloaded to my computer and opened in about 1/2 sec., a factor of 240! The document is dated 2001.

[BrianH]

With regards to the bluing of tools during grinding.....The first thing you MUST know is what your tools are made of. If (now regarded as old fashioned) high carbon, often called tool, steel it is imperative that no bluing occurs as it is a sure sign that the heat treatment has been ruined. Regular dipping into a container of cold water is the way to go.
If your tool is marked HSS, high speed steel, it would be necassary to heat it to orange... virtually impossible on a grinder... before heat treatment damage occurs. Bluing a HSS tool does no harm at all but dipping it hot into water risks crazing the surface so should be avoided at all costs.
All the best
Brian

[Stevekir]

With regards to the bluing of tools during grinding.....The first thing you MUST know .......

Thanks. Very helpful and clear. My tools are HSS.