Stropping - Compounds?

[Nomad]

Made a little strop the other day from a block of hardwood, with leather (flesh side up) on both sides. It's about the same size as a Spyderco Doublestuff, but taller to get a good hold while using it.

What's a good compound to use? I have some Autosol somewhere, but not sure if the grit is suitable. What about dry compounds, as used on polishing wheels? Also, is using the leather dry worth doing and, if so, what is the advantage? (Thinking of people using the inside of a belt as a makeshift strop, presumably without putting a compound on it.)

 

[Klenchblaize]

Starkie Sharp

 

[Mesquite]

I use Tormek P-70 stropping compound as well as the white stropping compound from Dave Budd

The tormek is good in that you don't have to keep charging the strop every time as it works as good dry as it does straight out of the tube.

 

[ged]

Autosol is fine, it's all I use. Some people use toothpaste. As you say it will work without a compound but it's more work and slower.

If you really want to get technical there are lots of compounds you can try but unless you're going to be entering sharpening competitions I wouldn't have thought it was worth while.

 

[British Red]

pink and green polishing compound for me - a 4 ounce bar is stupid cheap and will last your whole life

 

[Nomad]

Thanks so far, folks.

What's the deal with the colours for the solid compounds? Do the makers tend to use the same colours to signify similar grits/cuts? I ask because I got a load of polishing stuff ages ago (blocks of compound, and wheels/mops to put on a bench grinder) but never really used them (bought as a general 'might use' for the workshop, but haven't made anything worthy of polishing yet). Of the ones that look suitable for steel, I have, from this page...

http://www.thepolishingshop.co.uk/acatalog/Polishing_Compounds_180gm_Half_Round_Bar-p1.html

438T Green (cut 7, gloss 5)
P164 Blue (cut 4, gloss 8)
P126 Pink (cut 1, gloss 9)
Rouge Polishing Compound (no info, but presumably lower cut and higher gloss than pink)

The cut and gloss numbers are what's printed on the packaging labels. Given that these are geared for use on a polishing wheel, are they any different from whatever is used for stropping? The only difference I can think of is that, on a wheel, there might be more heat, so maybe the formulation is geared towards that, although that doesn't necessarily mean they won't work on a strop.

 

[Dave]

I use ashley isles green compound. Big bar, and autosol.

 

[British Red]

They work just dandy on a strop - pink is more of a final polish, green or blue for sharpening

 

[Caerleon]

I've been using Starkie Blue aka Smurf Poo for a while and rate it highly - from memory bought from a supplier in Leicester but should imagine it would be easily sourced elsewhere.

 

[Nomad]

They work just dandy on a strop - pink is more of a final polish, green or blue for sharpening

Yes, just been experimenting with an Opinel on some scraps of the same leather, starting from a few strokes with the fine side of the Doublestuff. Going straight to the rouge brought up a polish, but left strokes from the stone. The green one seems to knock these out nicely and leaves a pretty matt finish. For some reason, the blue one struggles to deposit anything on the leather, while the pink one is a bit better. The green and rouge are easiest to apply by a fair margin. I don't see a huge difference between the pink and rouge, but both bring up a decent polish. I'll mess about with them a little more and see which I prefer.

I have to say, using the compounds does make a nice difference - I had only used a strop dry before.

More or less sorted, I think. Thanks all.

 

[Robson Valley]

Honing compounds are abrasives, as are "polishing" compounds. When you inspect the result with a 10X magnifier, you will be able to see the fine scratches which cannot be seen with the unaided eye.

Chromium II Oxide is a green chemical. For honing purposes, the nominal particle size is about 0.5 micron. That implies that there are particles both larger and smaller in the mix.
Oxides of iron and copper range in color from yellows through reds to browns to black. Nominal particle size is in the range of 0.25 - 0.5 micron.
Aluminum Oxide (aluminium oxide, too) is white. Nominal particle size is 0.25 micron.

Some manufacturers will lace their honing compounds with other colors as both labels and as visible markers when loading the strop.

I have been using a mixed bar of CrOx/AlOx for freehand sharpening of wood carving tools for about 20 years.
I abandoned my good leather strops about 5 years ago. The waxy carrier in the bar of CrOx/AlOx softened the leather to the point that it rebounds
at the tool edge to round off the bevel = useless.
Instead, I use box card or file card stuck down on any hard smooth surface with tabs of masking tape or wrapped around mandrels of useful radius.
That's economical and as fresh as I could ask.

It is entirely possible to put a good edge on a new razor blade.

 

[Gooner]

Thanks for the link just ordered some pink and green, cheaper than using autosol my current compound

 

[Klenchblaize]

Just remembered I had this that's yet to be used and figure one or two of the sticks would work fine as strop compound too??

Cheers

K

 

[Gcckoka]

I am quite new to knife sharpening , can someone explain why should I use it? And what if I strop without it?

 

[Robson Valley]

Klenchblaize: One sure way to find out! If you haven't any old-fashioned filing cards, cut up a cereal/pasta/biscuit box for the hard card. Tape a strip of that to the edge of a bench with masking tape.
Scribble all over the unprinted inside surface with the honing/polishing compound of choice and try it. Your proof will be in service application.

Gcckoka: Even 1500 grit leaves a depressing mess of ragged edge and scratches. I notice that reducing those with honing compound is the magic step between a wood carving tool that works OK, versus one that's a pleasure to push.

 

[Gcckoka]

what compound should I buy and where?

 

[Dreadhead]

I have a big block of starkie blue, but the thing is rock solid. I usually rub it into my strop but it pulls fibers up due to the friction, but should I be adding water or oil to it to soften it up at all?

 

[Robson Valley]

Gcckoka: I don't know what you have for nearby suppliers of wood carving tools. Last bar of CrOx/AlOx that I bought was from Lee Valley. Years ago, I began with a monster chunk that I thought I'd never use up. But I kept cutting pieces off to give away and am down to a 1" thick slab so bought another. There's no better way to ruin the teeth on a hand saw than by cutting a honing bar. Maybe a band of pyrite crystals in a block of steatite soapstone but that's another embarassment.

Dreadhead: It's the waxy carrier in the bar that makes it so solid. My shop is cold (50-60F) when I open up on winter days. I put my bar in my shirt pocket to warm it up, to soften the wax. You could do no wrong with 30C/90F water and your honing cpd bar in a plastic bag for a warm-up. Waxes, even petroleum waxes, commonly melt at about 60C/150F.

 

[Tonyuk]

Have a look at Cousins, they sell a good few compounds for polishing;

https://www.cousinsuk.com/category/compounds-polishing-waxes

As well as the 3M micron lapping film if you want a very fine edge;

https://www.cousinsuk.com/product/3m-abrasive-lapping-film


I use car polish meant for chrome, available on e-bay for quite cheap. You can find good leather belts in charity shops everywhere.

Tonyuk

 

[Gcckoka]

Gcckoka: I don't know what you have for nearby suppliers of wood carving tools. Last bar of CrOx/AlOx that I bought was from Lee Valley. Years ago, I began with a monster chunk that I thought I'd never use up. But I kept cutting pieces off to give away and am down to a 1" thick slab so bought another. There's no better way to ruin the teeth on a hand saw than by cutting a honing bar. Maybe a band of pyrite crystals in a block of steatite soapstone but that's another embarassment.

I don't have any suppliers of wood carving tools in my country Which site should I visit and which compound should I buy? I have few really high quality leather belts on which I strop y knives.