To strop or not to strop?...

[woodbloke]

I keep on re-visiting my strop on the honing bench...just a lump of leather glued to a piece of mdf and smear of Vaseline with Jewelers Rouge as a cutting medium. What I tend to do is to finish on the SS 3M films (1 micron) using the 'Ruler Trick' on the reverse (or back) and then a couple of passes, no more, on the honed bevel with the strop, followed by another quick session on the back using the RT.

I know that there's an argument for saying that there's a minute amount of 'drubbing' of the honed bevel that takes place if stropping is done and I know that PaulC will show us his mdf and Autosol way...but I've found that that method doesn't work for me as the edge doesn't get perceptibly sharper, whereas on the strop, it seems to.

Each time I sharpen, I go back to the 3M films and re-hone, so the strop is not used as a method of honing, merely to get that final smooth, polished edge after the 1micron film. Also bearing in mind that Jeweler's Rouge is just about the finest abrasive commercially available (is there anything that cuts finer?) I dont' think the so called 'drubbing' issue is relevant as any rounding over that is created will be removed at the next honing.

How good is Chromium Oxide (as sold at WH) compared to JR?

Interested to hear others thoughts on the matter - Rob

 

[Paul Chapman]

PaulC will show us his mdf and Autosol way...but I've found that that method doesn't work for me as the edge doesn't get perceptibly sharper, whereas on the strop, it seems to.

But I don't use MDF. It's too rough and full of "stuff". Try a closed-grain wood planed dead flat.

Cheers :ho2

Paul

 

[woodbloke]

Tried it Paul...still doesn't work for me, but I'll give it another go - Rob

 

[Derek Cohen (Perth Oz)]

Hi Rob

I am a fan of sharp edges. I used to be a fan of strops to obtain sharp edges, but have changed my method in this regard.

I do believe that stropping works well. My change of mind has nothing to do with the outcome. Indeed, I have an article on stropping, one where I compared LV green compound with diamond paste (each 0.5u), both on hard horse butt leather ...

http://www.inthewoodshop.com/WoodworkTe ... paste.html

The reason a strop works is, I suspect, that it does create a slight rounding of the bevel - which is akin to adding a micro-mico bevel.

The reason I stopped using a strop is simply because I did not need one anymore. I have a sharpening station where my stones are permanently available. When I suspect that an edge is losing its keenness, I simply flick the blade over the stones.

I do have a couple of "strops" in my travelling kit (for demonstrations at wood shows). I sharpen on cast iron plates and diamond paste. Or strop on 0.5u 3M film on glass-glued-to-wood. All flat mediums.

Regards from Perth

Derek

 

[dunbarhamlin]

Is jewellers rouge (rust powder) going to do much cutting of tool steel, or does it rather work like talc (my choice) and just work any remaining wire edge?

 

[Paul Chapman]

Looking at your original post again, if you use a strop and the ruler trick, then you really need to strop on something hard, like a piece of wood. You can't use the ruler trick on leather or you will tear it (if you move the blade sideways). But you could use it on wood. If the strop is going to improve the sharpness, you really need to use it on both sides of the blade. I don't use the ruler trick but I finish both sides of my blades on the wood/Autosol strop and get very sharp results.

Cheers :wink:

Paul

 

[Derek Cohen (Perth Oz)]

Looking at your original post again, if you use a strop and the ruler trick, then you really need to strop on something hard, like a piece of wood. You can't use the ruler trick on leather or you will tear it (if you move the blade sideways). But you could use it on wood. If the strop is going to improve the sharpness, you really need to use it on both sides of the blade. I don't use the ruler trick but I finish both sides of my blades on the wood/Autosol strop and get very sharp results.

Cheers :wink:

Paul

Actually Paul, I find that I can get a significant improvement in a dull BU blade (that is, refreshening the edge) by stropping/honing the back alone. This may be done with or without the Ruler Trick. Further, the RT may be done on leather as long as the movement is away from the sharp end (that is, pull backwards only).

Why only strop the back? This is sometimes all that one can do if you have a high angle micro secondary bevel and do not want to go to the trouble of using a honing guide to hone the bevel face.

Regards from Perth

Derek

 

[woodbloke]

Looking at your original post again, if you use a strop and the ruler trick, then you really need to strop on something hard, like a piece of wood. You can't use the ruler trick on leather or you will tear it (if you move the blade sideways). But you could use it on wood. If the strop is going to improve the sharpness, you really need to use it on both sides of the blade. I don't use the ruler trick but I finish both sides of my blades on the wood/Autosol strop and get very sharp results.

Cheers :wink:

Paul

Paul, I've just tried what you mentioned, ie using a piece of dead flat wood and not mdf with the JR/Vaseline combo and it seems to work...I'm not sure if it's better than the leather, but it's better than the mdf by a mile. Just to reiterate, it's a couple of stokes backwards with the bevel on the wood and then the back polished again with the RT (side to side) on the 1micron 3M film. I haven't got any Autosol but it's on my market day outing list tomorrow on the Blokebike...that's if I don't get blown off it in the gales [-o< - Rob

 

[Philipp]

How good is Chromium Oxide (as sold at WH) compared to JR?

Chromium Oxide is much harder (Mohs-hardness 9) than Jeweller'r rouge which is iron(III)-oxide (hematite) with a Mohs-hardness of 5.5 - 6.5. It's good for polishing non-ferrous metals, but Chromium oxide ist significantly more effective on steel.

I use synthetic chromium oxide (the pigment) on my leather strop and love the high gloss it gives to steel.

I'd doubt whether Talc is able to remove a wire egde from a plane iron, since talc is extremely soft and even cannot scratch one's finger nail.

Regards, Philipp

 

[woodbloke]

How good is Chromium Oxide (as sold at WH) compared to JR?

Chromium Oxide is much harder (Mohs-hardness 9) than Jeweller'r rouge which is iron(III)-oxide (hematite) with a Mohs-hardness of 5.5 - 6.5. It's good for polishing non-ferrous metals, but Chromium oxide ist significantly more effective on steel.

I use synthetic chromium oxide (the pigment) on my leather strop and love the high gloss it gives to steel.

I'd doubt whether Talc is able to remove a wire egde from a plane iron, since talc is extremely soft and even cannot scratch one's finger nail.

Regards, Philipp

Thanks for that Philipp, just what I was looking for...may have to order some from Workshop Heaven next time I place an order - Rob

 

[Racers]

Hi,

I am a stropper, leather (smooth side) and Autosol, I am getting a loverly sharpe edge.

Pete

 

[Paul Chapman]

Looking at your original post again, if you use a strop and the ruler trick, then you really need to strop on something hard, like a piece of wood. You can't use the ruler trick on leather or you will tear it (if you move the blade sideways). But you could use it on wood. If the strop is going to improve the sharpness, you really need to use it on both sides of the blade. I don't use the ruler trick but I finish both sides of my blades on the wood/Autosol strop and get very sharp results.

Cheers :wink:

Paul

Paul, I've just tried what you mentioned, ie using a piece of dead flat wood and not mdf with the JR/Vaseline combo and it seems to work...I'm not sure if it's better than the leather, but it's better than the mdf by a mile. Just to reiterate, it's a couple of stokes backwards with the bevel on the wood and then the back polished again with the RT (side to side) on the 1micron 3M film. I haven't got any Autosol but it's on my market day outing list tomorrow on the Blokebike...that's if I don't get blown off it in the gales [-o< - Rob

Why not try the ruler trick on the wood/JR/Vaseline as well? From what I remember, you place the ruler over a couple of small pins, so it should be easy enough to try it out.

I'm not sure whether Autosol is better than JR as I've not done a comparison - probably not a lot in it.

Incidentally, I do more than a couple of strokes on the strop - but then I'm going from a green, extra fine DMT stone which is probably not as fine as your films.

Cheers :ho2

Paul

 

[Philipp]

Never heard of Autosol before, so checked the net a bit.

The Metal polish from Autosol contains alumina (not further specified) as abrading agent.
From the data provided by Autosol (MSDS) one can't see the grain size or the type of alumina being used in Autosol. I know that business a bit and I am dealing with alumina in my job, so I suppose that so-called soft-burned aluminas are being used in Autosol, i.e. alumina that only in parts is corundum, the main phase being a gamma-alumina with a considerable lower hardness. In these aluminas the edges of the crystals are slightly rounded on their edges again lowering the abrasiveness.

Even corundum (= alpha-alumina) is slightly softer than chromium oxide despite both having 9 on the Mohs-scale.

What's good for polishing not necessarily is good for achieving razor-sharp edges on our tools. We are not after shiny surfaces but we are striving for infinitesimal egdes.

For final stropping a as hard as possible and as fine as possible material should work best. Synthetic chromium oxide, when micronised, is fine-grained enough (below 1 µm) and it has sharp crystal edges giving good abrasional properties.
Diamond-paste below 1 µm would work even better.

BUT...who cares :wink: ?

Regards, Philipp

 

[jimi43]

I feel that I've been beamed up and dumped into the "cut-throat razor" forum!! :mrgreen:

I think we should all buy one of them there microscopes that Maplin is selling cheap this year for Christmas and take "edge" shots that are so popular in sharpness shoot-outs over there on the "other" side!

I have thoroughly enjoyed this debate so far...wonderful to know the chemistry behind our traditional and not so traditional pastes and the methods used.

I look forward to the next episodes! =D>

Jim

 

[János]

Hello,

Jeweler's rouge is red iron oxide mixed with wax. My strop is a piece of thick (3~4 mm) leather (cow hide) bonded to a flat fir board, with smooth side up. But I use naphtha to wet/lubricate the rouge. It works well on low alloy tool steels. After a few uses the leather becomes saturated with the rouge, and works fine even without lubrication.
A finer cutting alternative to jeweler's rouge is tripoli earth.
Soft surface leather strops round over the edges slightly, but this minute amount of rounding is not a real problem on plane irons. By the way, abrasive clots, papers and films (belt sanders, scary sharp etc.) behave like leather strops in this respect.

Have a nice day,

János

 

[dunbarhamlin]

I'd doubt whether Talc is able to remove a wire egde from a plane iron, since talc is extremely soft and even cannot scratch one's finger nail.

Regards, Philipp

I'm not trying to further abrade the edge, rather just work off any remaining wire edge. The talc doesn't need to cut, it just means my jeans last longer.

 

[woodbloke]

Never heard of Autosol before, so checked the net a bit.

The Metal polish from Autosol contains alumina (not further specified) as abrading agent.
From the data provided by Autosol (MSDS) one can't see the grain size or the type of alumina being used in Autosol. I know that business a bit and I am dealing with alumina in my job, so I suppose that so-called soft-burned aluminas are being used in Autosol, i.e. alumina that only in parts is corundum, the main phase being a gamma-alumina with a considerable lower hardness. In these aluminas the edges of the crystals are slightly rounded on their edges again lowering the abrasiveness.

Even corundum (= alpha-alumina) is slightly softer than chromium oxide despite both having 9 on the Mohs-scale.

What's good for polishing not necessarily is good for achieving razor-sharp edges on our tools. We are not after shiny surfaces but we are striving for infinitesimal egdes.

For final stropping a as hard as possible and as fine as possible material should work best. Synthetic chromium oxide, when micronised, is fine-grained enough (below 1 µm) and it has sharp crystal edges giving good abrasional properties.
Diamond-paste below 1 µm would work even better.

BUT...who cares :wink: ?

Regards, Philipp

This is really interesting...from what you're saying, I reckon the way forward is a tub of the real deal from Workshop Heaven, which would appear to be even better that Autosol. I think I may well also treat myself to a new bit of thick leather to make another strop - Rob

 

[Racers]

Wow £18, it would have to be something else to get that amount of my wallet.

Pete

 

[Sgian Dubh]

I always strop a bit after sharpening. Usually I just curse away in fruity Anglo-Saxon to get me in the appropriately stroppy frame of mind, then I flip the pointy end of the chisel or plane on the palm of my hand. The rough skin, calluses and sweat in my left palm provide an extremely fine and effective medium for the ultimate edge. Prior to that I strop using the palm of my right hand: the calluses are a little larger, the skin a little rougher, and the sweat has a slightly different alkalinity making right palm stropping a little more aggressive, but it's the dog's nuts as a preparation for the final, ultimate, unsurpassable, left palm stropping.

Full instructions are available here. I wonder if I should include one of those quite popular, but daft emoticon thingies to indicate there might be a slight lack of seriousness in my post. Slainte.

 

[Doug B]

Wow £18, it would have to be something else to get that amount of my wallet.

Pete

Here you go Pete, 4 different types, your could strop to your hearts content :lol: & only £7 a tube

http://www.executive-shaving.co.uk/shav ... -paste.php

Though the 260 looks the business, diamond & aluminium oxide particles,

http://www.executive-shaving.co.uk/thie ... -paste.php