Honing chisel backs

[Jim Dunn]

Decided that I needed to sharpen my chisels. Now it's not a gloat at all. I have a full set of Sears chisels. Butt chisels I believe and noticed that the backs are not flat or for that matter very smooth. I've used a plate of glass and 220 wetordry paper to try and get the backs as smooth as possible. Also to flatten out the backs as they seem to be bowed slightly. I assume that I need the backs flat all the way to the cutting end. They are, and I'm guessing, about .010 high in the middle.

Am I on the right track here? Do higher quality chisels also require that the backs be honed?

Jim

[Brent Smith]

Hi Jim,

Just about any chisel you buy will need some work. Supposedly, the more expensive the less work, but, this doesn't always hold true. You might want to start with a more agressive grit to get them flat and then work your way up to a shine. And yes, they need to be flat to the cutting edge.

Brent

[Mark Stutz]

Jim,
I agree, it will go fast starting with a coarser grit. The entire back does not have to be flat, as long as the last 1/2 to 1 in. is flat. Would take forever to do the entire back!

[Mike Wenzloff]

Would take forever to do the entire back!
In general it takes me about 6-10 minutes per chisel, depending on how bad they are, for the initial flattening--but I've been sent some really bad ones [very recently] that have taken 15 to 20 minutes each on the larger sizes.

I use a staionary belt sander with 120 grit for the inital flattening, but a smaller belt sander held upside down in the bench vice works too.

After flattening, it is just a matter of working your way up through the grits, whether via SS and/or in combination with stones. This can be another 5-8 minutes.

I've used disc-based power sharpeners as well for higher grits, though I still use either paper on a granite plate or stones for the final flattening and polishing.

Take care, Mike

[Don Naples]

Jim: The WetorDry paper you are using is Silicon Carbide. It is intended for sanding paint in autobody shops and for abrading non ferrous metals. For abrading steel, use Aluminum Oxide. It does not break down as quickly as SiC and will give you time to get some metal removed. Once the tool is flat and the bevel sharpened, SiC is a sharp abrasive that can be used to refine a tool edge, though I still prefer AlO2 as it lasts longer so enables me to sharpen more tools between abrasive replacement. if you use a belt sander, don't finish it to a burr edge as it can remove the temper in the tool. Finish the final edge by hand to prevent this.

[Mark Stutz]

Mike,
I agree. I was referring t trying to do it by hand!:eek: I usually use some form of tailed device as well for the initial work.

[Mike Wenzloff]

Hi Mark...I assumed you were talking doing it by hand. I just like balance <g>.

Some people can take on tasks like these by hand that, well, go further back in time than the tool itself for the sake of "doing it by hand."

I figure these types of tools we [generally] deal with were made by machines with little hand work involved so it doesn't bother me at all to "tame" them with powered tools.

But for each their own.

Take care, Mike

[Jim Dunn]

Well I started with 80 grit paper and after about 2 hours on 5 chisels I have them mostly flat. You could actually lay them on the glass and get them to rock back an forth.:eek: So I tried to make them as flat as possible then concentrate on the last half of an inch. Ready to take it to the next grit tonight:o This is just a test to see if I can do this ,as I intend to purchase new chisels of a higher quality and do the same. Hopefully everyone is right and better chisels will be flatter.:confused:

Jim