Sharpening Conundrum

[BigMP]

So I have an sharpening conundrum that I simply cannot understand:

I sharpen by first creating a hollow-grind using a shop-made slow-speed bench grinder setup. I follow that step by free-hand honing on water stones starting with a 1200g Norton water stone followed by an 8000 high quality japanese water stone. Last and final step is a swipe or two on a strop. If you are still fuzzy on my method, I use the same technique that Gary Rogowski uses. So I briefed you on my methods, now here is my conundrum.

I can't seem to achieve a mirror finish on the backs of my chisels or plane irons no matter how much I try using the 8000g water stone; however, that very same water stone seems to produce a brilliant polish on the bevel side of the chisel/iron. Now, I want to add that we are talking about high quality tools here (LN, BlueSpruce) and I can still get my tools very sharp but I just can't understand why I can't achieve that fine mirror polish.

Interestingly enough, I have been able to produce the mirror polish on the backs using 2500g wet sand paper; however, I prefer to use my stones because they don't really wear out and they are always there for me to use, granted I keep them flat and true... which I do.

So can anyone shed some light on my situation? And has anyone experienced the same problems? Thanks in advance for the replies!

Mike

[Vic]

LOL..I just had the same problem. Turns out my wet/dry 3m paper that is 1500 grit is the same as the 8000 grit Norton stone, in micron grit. I went and bought some 2000 grit wet/dry and could actually go one step up. But, I can get really close to the polish I want now and am taking insanely thin shavings. So, good enough. Btw, I use sand paper to get an initial bevel, instead of a grinding wheel and go to my 1000/4000 then 8000 water stones...finishing with the 2000 grit wet/dry. And I don't free hand. I got the shakes, man.

[iSawitFirst]

Going from 1200 to 8000 is quite a jump. Try using 3000 between these.

Check out these water stones.

[BigMP]

Vic - The hollow grinding really helps with the steady hand issue. Think about it like balancing the bevel on 2 distinct points rather than the whole bevel side.

ISIF- Looks like ill be purchasing the 12000g stone , but just to note I really don't use the 1200g stone on the backs of the chisels/irons, I only stick to the 8000g for that.

Anyways, thanks for the response guys.... anyone else want to chime in?

[Vic]

Vic - The hollow grinding really helps with the steady hand issue. Think about it like balancing the bevel on 2 distinct points rather than the whole bevel side.

ISIF- Looks like ill be purchasing the 12000g stone , but just to note I really don't use the 1200g stone on the backs of the chisels/irons, I only stick to the 8000g for that.

Anyways, thanks for the response guys.... anyone else want to chime in?

After seeing Denalb Pochowslki's (sp) LN video, I decided to keep my irons away from the grinding wheel. Plus, it only take a second to set it in the guide. I like that 1200 grit stone too.

[protectedvoid]

Vic - The hollow grinding really helps with the steady hand issue. Think about it like balancing the bevel on 2 distinct points rather than the whole bevel side.

ISIF- Looks like ill be purchasing the 12000g stone , but just to note I really don't use the 1200g stone on the backs of the chisels/irons, I only stick to the 8000g for that.

Anyways, thanks for the response guys.... anyone else want to chime in?

I would assume that in order to achieve a mirror finish on the backs of your iron, you would first need to remove enough metal to get a fine scratch pattern on the back. Try 1000 grit wet/dry sandpaper first, then follow up with your 8000 waterstone. It may be that the 8000 stone does not remove enough of the material to eliminate the deeper scratch patterns in the iron from the original grinding.

[wilburpan]

It may be that the 8000 stone does not remove enough of the material to eliminate the deeper scratch patterns in the iron from the original grinding.

Without seeing your chisels, that is most likely issue.

I don't think you need to worry too much about the mirror polish, however. The theoretic goal of a perfectly sharp edge is the intersection of two flat planes. A mirror finish is not necessarily an indication that something is flat -- think about a funhouse mirror. A mirror finish just means that the scratch pattern in the steel is very regular. If you use natural waterstones for sharpening, you can get very sharp edge with a matte appearance to the tool. I have a post on my blog about this.

The other way to look at this is, if you get edges that are sharp enough for your needs, who cares whether you have a mirror finish or not?

[protectedvoid]

Without seeing your chisels, that is most likely issue.

I don't think you need to worry too much about the mirror polish, however. The theoretic goal of a perfectly sharp edge is the intersection of two flat planes. A mirror finish is not necessarily an indication that something is flat -- think about a funhouse mirror. A mirror finish just means that the scratch pattern in the steel is very regular. If you use natural waterstones for sharpening, you can get very sharp edge with a matte appearance to the tool. I have a post on my blog about this.

The other way to look at this is, if you get edges that are sharp enough for your needs, who cares whether you have a mirror finish or not?

I agree. Though, since I use the sandpaper method of sharpening, I typically will take a few strokes on the back of my irons as I work through each grit to eliminate any burr that builds up while honing the primary / secondary bevels. This has the added benefit of creating a mirror finish on the back of the plane irons, near the very tip. For me, that's just an indication I've removed any burrs that might have been hanging around.

[protectedvoid]

Going from 1200 to 8000 is quite a jump. Try using 3000 between these.

Check out these water stones.

I looked long and hard at those superstones. I figured I'd give these a try first. Specifically, the .5 micron chromium oxide sheets.

[iSawitFirst]

I looked long and hard at those superstones. I figured I'd give these a try first. Specifically, the .5 micron chromium oxide sheets.

Good find! I think these would be good for certain tools and a good short-term solution. In the long run, I suspect the stones will be a better value.

[protectedvoid]

Good find! I think these would be good for certain tools and a good short-term solution. In the long run, I suspect the stones will be a better value.

Yeah. You know what they say. A poor man pays twice. I figure, for the cost, these micro-abrasive sheets will get me by till Christmas rolls around. Then, when I have a little more disposable income, I'll be able to pick up a few waterstones.