Next on my tool list are the cold and hot chisels. What is a good sharpening angle for them? And for a hot cut in the hardy hole?

 

60 deg is the gold standard, with secondary angles about 1/2 that, thin for hot, stubby for cold. A slightly curved (like an axe) profile helpes as well. Most tools and knives like 60 degrees, but the secondary bevel plays a big role in performance.

Thanks Charles. But what do you mean with secundairy angle half of 60?

I know woodworking chisels. They usually are 25 degree primary (grinding) angle and 30 degree secundairy (wetting) angle.

 

I have the normanclacher wrong, 

the sharp edge at 60 the the other angle (to give you clearance to work) at about 30.  A hot cut is thin all over (thing brick massons chisel) wile a cold cut is thicker. 

 

disappearing post bug?

yup.  typed out a long reply.  gone.

That's a pitty!

 

Today I finally got round to sharpening a couple of cold chisels. They are just the regular type from the jome centre. On the grinder, and I made a slighty rounded profile at close to 60 degrees. They work indeed a lot better when sharp! 

Now onto my hardy cutoff tool. I have bought one, making larger tools like hardy stuff isn't quite in my repertoire yet and I learned to appreciate the cutoff tool on my beginners course. The angle of the cutting edge on this thing is very close to the angle on my cold chisels. Should I worry about that allready and start to do a lot of grinding to get it shallower? Or just live with it and see how it goes in the future?

 

A cold cut would have an "A" shape close to  60 deg all the way to the anvil, wile a hot cut is going to look more like an axe. As its hot steel you only need a thin section, say 1/4" with a 60degree cuting edge.  If your hardy is thick thats ok, dont sweat it. A brick chisel, peice of spring cut to fit diaginaly, a sucker rod knuckle...

all can be made in to servicible hot cuts. 

Thanks. I will use it for a while and see if I like it this way.