Questions about finishing stages of sharpening

[Starfish]

Hi all,

I'm getting better at sharpening, and seem to do a pretty good job with a Sharpmaker (and a coarse stone for reprofiling). I have a strop that I use also at the end, although I can't say that I've noticed a huge difference going from the fine rods to the strop. Then again, that could just be poor stropping technique :footinmou

So now that I have the basic steps down, I'm getting more interested in refining my finishing technique.

Here's the questions:

1. What is the difference between stropping and using the ultrafine Sharpmaker rods (or going to higher grits, as on the EdgePro)?

2. What are the advantages/disadvantages of going past the fine rods and into stropping/ultrafine/polishing tapes territory?

Thanks for the help,

Matthew

 

[The Tourist]

You must pick the edge for the job. Cutting wet vegetables or cubing semi-frozen meat is easier with a slightly toothy edge. Paper products and cardboard seem to need a mirror finish for push cuts, at least, I find that easier.

I used to be a fanatic about getting that burr off. I'd polish with every fine stone, than use 4000 series polishing tapes and then strop with white rouge. I found that it isn't that critical. I press lighter as I finish.

I'm trying to duplicate Mick Strider's factory finish, that is, slightly toothy with no drag. I'm using a 220 grit Edgepro waterstone, and then a light buffing with the polishing tapes. If a tiny flat spot remains, I strop it a few times with the rouge left on the strop.

Enjoy the knives. Spend less time searching for the perfect edge and more time staring into your woman's eyes.

 

[thombrogan]

1. Stropping pulls the edge away from the abrasive so it doesn't put as much pressure on the edge or remove as much steel. The higher-grit, harder stones (such as the ultra-fine on the Sharpmaker) still have you push the edge into the abrasive. The harder and finer the final abrasive is, the finer you can arrange the steel at the edge. That way, you'll reduce the chance of building up a wire-edge when you use light, alternating strokes on the ultra-fine stones. If a wire-edge is formed despite using light, alternating strokes on the ultra-fine hone, it will be smaller and easier to remove with stropping or rehoning.

2. The advantages seem to be that you'll get the edge even finer/sharper than when using the ultra-fine hones while possibly reducing less metal than the ultra-fine hones. The disadvantages are extra time, technique, and equipment needed.

I don't strop yet, so my opinions on stropping are worthless, but I do use the Sharpmaker all of the time. For a no-nonsense atom-splitting edge, you only really need the diamond sleeves and the ultra-fine hones.

If you like nonsense edges as much as I do, It's fun to run the edge through the 'gauntlet': Reprofile with the diamond sleeves and then use the medium and fine stones to smooth out the furrows the diamonds dug into the edge before finishing with with ultra-fine hones. Of course, after one monster run, you only really need the ultrafine hones to touch up and the medium and ultrafine to resharpen until your edge is too close to the shoulders and needs another reprofiling.

Hope that was helpful.

 

[Cliff Stamp]

Starfish :

1. What is the difference between stropping and using the ultrafine Sharpmaker rods (or going to higher grits, as on the EdgePro)?

Stropping usually creates a slightly convex edge as most strops are not very hard surfaces. This will add some durability to the edge at a loss of a much smaller amount of cutting ability. Unless you press really hard into the strop you won't notice this effect because it will be too slight.

The other main difference (assuming the grits are similar), is as Thombrogan noted you are mainly comparing edge trailing vs edge facing honing and the latter is much more aggressive at the same grit. This as well isn't a huge factor, it does make a difference, but not as much in regard to the quality of performance of the final edge, but again as Thombrogan noted, does effect technique .

Cutting into a hone removes burrs very quickly, you can usually eliminate even a bad burr 1-2 passes, but you can also create them just as quickly if you use too much pressure and deform the edge instead of grinding it. The Edge Pro is much better in this regard than a fine rod as the pressure isn't as concentrated. Edge trailing sharpening doesn't remove burrs readily, so an edge should be decently crisp before stropping.

The steel type will effect burr formation readily as well. High alloy steels that are hard to machine, but are left soft are really prone to burr formation. Low alloy steels that are ran hard are very resistant to burr formation and generate crisp edges really easy.

In short, as long as the grits are similar on rod vs stropping, the resulting edges are not going to be significantly different.

2. What are the advantages/disadvantages of going past the fine rods and into stropping/ultrafine/polishing tapes territory?

You lose slicing ability very quickly, and gain push cutting ability very slowly. High polished edges are also slightly more resistant to impacts (chopping and such).

Ichabod Poser :

I'm trying to duplicate Mick Strider's factory finish, that is, slightly toothy with no drag.

Belt + buffer, with care on the buffer not to go too long as you will polish out all the grind lines and these are what given the toothy effect. The more coarse the belt the more tooth. Some steels don't require any buffing at all as the edge will form very crisp, these are the harder steels generally. If you don't have a buffer just use a strop with a polishing compound (CrO).


-Cliff