This is probably well-trodden ground but I’m hopeful that someone will have gone through this before and can help.
I have a nice set of oil stones that I use for ordinary sharpening and they work great. But I still struggle when I get my hands on an old plane or chisel and have to regrind the bevel or just grind nicks out.
I have a bench grinder that came with the typical gray wheels. These things are super slow and I’ve seen many people in magazines using the white and blue-green grinding wheels but I can never find those. I’ve looked in my local Woodcraft and a couple of tool places but they don’t have the Norton brand. I am unfamiliar with the other brands and so don’t know if they cut as fast or not.
Once long ago, I stumbled across a 3x6” DMT diamond plate for cheap ($35). It is a steel plate marked “Dia-Sharp Coarse” on the side. This cut really fast for awhile. After a long session of trying to flatten the back of a plane iron, it seemed to slow its cutting speed dramatically. I did clean it more than once with water but that didn’t speed up the cutting at all. The surface left behind on the plane iron was very shiny so it made me wonder if I had somehow worn the abrasive out. I read somewhere on this forum that diamond plates have this plateau; as if they begin life more coarse than the rating suggests and you soon wear them down to that. I don’t know but I do know that the one I have is no good for basic regrinding of anything.
So here’s my questions:
Do diamond plates have this “plateau” effect or did I possibly just get a bad one?
Given that I only want to use my bench grinder for coarse regrinding of a new bevel, which grits of grinding wheels should I buy? I’m assuming I can find them online at multiple places so I just need to choose some grits.
What’s the difference between the white wheels and the blue ones?