Thread: Trouble with water stones

Matt,

The Chart was published in Sharpening Made Simple by Steve Bottforff.

I notice the same thing when I sharpen; when I get a burr on chisels, plane irons and knives, the finished edge pops hairs off like a razor blade; without a burr, it barely scrapes them off.

The course norton silicon carbide oil stone is 120 microns, the extra course DMT is 60 microns and the 220 shapton is 66 microns. That would explain the speed difference. I read from several sources that water stones cut much faster than oil stones at a given grit, which is why I was expecting an improvement in cutting speed.

Onimaru,

No worries, my first post was not very clear, so I would of thought the same thing.

Jimmy,

I've heard from many people about their positive experiences with the norton 4/8k. I'm still trying to figure out why I'm unable to get good results with mine. I need to give my set to an experienced norton user to see what what they think.

Lesslemming,

I usually feel the burr with my thumbpad. I just tried the thumbnail test, and the shapton 220 did raise a burr on a small kitchen knife after fifty passes with high pressure. I guess I was just expecting it to outperform my old oil stone.

As for the DMT 15m versus the shapton 14.8, the edge off the DMT generally shaves better. When I stop with the 600, I take light strokes back and forth until there is not trace of a burr, so I doubt that's the difference I'm noticing. As I read more about different Japanese stones and search my memory, I think the DMT and shapton leave about the same edge on carbon steel; the difference is more pronounced on stainless alloys.

My four month old extra course DMT has several spots where the diamonds have been completely worn off and it cuts at about the same speed as a shapton 1k. It's still a good lapping stone though. It has been used to sharpen a couple hundred kitchen knives, a smaller number of chisels and plane blades, and been used to lap my shaptons, so I'm still pleased with its performance.

Thanks Everyone,
Bob

I just orded a sigma silicon carbide ceramic water stone from japan. They are made for sharpening HSS steel, so I think it will be a viable replacement for my silicon cabride oil and DMT stones.

One clear question for you:
do you get good results with your not-so-big-burr setup?
That´s the big question. It´s like we always say, "test shave!".

If you set the bevel on your bigger knives on the naniwa, or the shapton without creating big burrs,
and move along to whatever you finish on, maybe the norton 8k or shapton 8k,
do you get very smooth edges?
Does it shave arm and leghairs easily, maybe even pop them?
Hows the tomato doing, is it frightened to see your blade,
or is it not quite there?

If your edge is good, I wouldn´t bother the burr.
If it is not good I would try to figure out where you went wrong,
i.e did your knive pass any shaving test at all during the ~3k stage?


The thing is, I hardly look for burrs on the lower grits.
If they appear it´s fine. If they don´t, but the edge is built evenly I am fine, too.

The second thing is a burr is not your friend. On the low grit range they just happen and can be indignitive of being through".
But you want to remove it as quickly as you can. Usually on the 3k stage it should not be felt anymore.
A burr will cut awesome. Like it does on razors (where burr has to be [and is] defined different]. You get people to pass HHT with razors comming from DMT 325.
These burrs are deceptive and will not give good results in cutting anything for a long time

For a good coarse grit solution, that never dishes out, use the scary sharp system of wet/dry sandpaper. I have never found a better method... but it is more expensive. I use it up to & including 1000 grit on straight razors when repair work is necessary. After that I use waterstones etc.
When you finish with the sandpaper it has created a specific "shape" to the bevel that will need to be reshaped on the subsequent stone. That takes about 25-50 laps on regular carbon steel razors.

Just my $.02,

Lesslemming,

I just tried the following: honed a small parring knife on shapton 220, followed by 1k, 4k and 8k. The edge began to shave after the 4k. I held the knife perpendicular to a dmt and dulled it until you could not cut yourself if you tried. I then sharpened it again starting with the naniwa 220, then 1k, 4k and 8k shaptons. The edge started shaving decently after the 4k. I was expecting the new stones to be much faster than my silicon carbide oil stone, which is why I was dissconcerted when I did not quickly get an easily detectable burr.

I'm well aware of the issue of leaving the burr on thinking the edge is sharp. That is not the case with the knives, chisels and plane irons I sharpen. For polished edges, my ususal progression is course DMT or crystalon, shapton 1k, 4k, 8k, .5m pasted strop and .05m pasted strop. The resulting edges are sharp and durable. Unless the tool is abused, it can be kept sharp with a pasted strop for a very long time.

One thing I've consistently found is that unless I start by getting a burr, whether it can be detected with a thumbpad, fingernail or pin, the edge does not respond to a sequence a polishing stones as it would otherwise.

In conclusion, I expected too much speed out of the shapton and naniwa, and I used the incorrect test to see I was getting a burr.

Thanks
Bob