Stroping Question

[Jaybe Bowen]

Lets say I sharpen my knife at 20 degrees, at what angle do I strop at?

[CliffCurry]

Jaybe Bowen wrote:

Lets say I sharpen my knife at 20 degrees, at what angle do I strop at?

short answer is 18 degrees, 2 less the the sharpening angle.  Use light to medium pressure to avoid the flexible leather rounding off and dulling the apex as it passes by.  Happy sharpening!

[Martin Hainsworth]

Is that because the leather has more ‘give’ in it than a solid stone?

At that angle are you actually stropping the edge or the bevel?

Just trying to work out the physics behind it. At the moment I’m stropping at the same angle I’m sharpening at.

[Mark76]

Yes, that’s because leather has more “give” to it. If you use a balsa strop and don’t use too much pressure, there’s not need to lower the angle.

Molecule Polishing: my blog about sharpening with the Wicked Edge

1 user thanked author for this post.

Martin Hainsworth

[cbwx34]

My .02, experiment and see what works best for you.

[Anonymous]

If I am stropping with Balsa, am I applying any diamond paste? Am I keeping it wet, or allowing it to dry before stropping? I’ve tried to ask this question in several threads, but with no results. I could easily get Clay’s attention with a Private message but information like this should be available for all newbies.

[tcmeyer]

Bill:  I’ve never used balsa, but FWIW I never used any wetting agent with my leather strops.

Balsa, leather, kangaroo, hardwoods and even brass are all just media with varying levels of softness used to hold the diamond particles.  I see the paste as just being a convenient media for carrying the abrasive grit so that it may be more easily spread onto the substrate you’ve chosen. Once embedded in the substrate, the particles don’t need the gooey paste anymore.

Whether to use a wetting agent is a personal choice.  Does it keep your substrate material pliable?  Do you think you need a lubricant?  I think it’s well known that while lubricants may make for a smoother finish, they inhibit the abrasive process, making it take a little longer to achieve the same results.

As I said, I haven’t tried balsa, and I don’t use leather anymore either.  I have tried paste on hardwood (maple) and on brass and never with a wetting agent.  I thought they worked quite well.  I prefer the film on a hard substrate.  I always felt that film has more of a cutting effect, while paste/spray has more of a burnishing effect.

2 users thanked author for this post.

Alan, CliffCurry

[Anonymous]

Thanks Tom… my only reference to wetting is wet sanding paint. the water acts like a lubricant and it suspends the grit as it glides across the surface, insuring that the grit would gouge the surface..

I can get an edge incredibly sharp, and have it look good to the naked eye .. but under the scope @ 50X it looks horrible, and at 500X it looks like a cheese grater

I’ve seen some mirrored edges that look mirror like under the scope. I should say, they are 90% scratch free. My edges are about 60% mirrored with scratches, but still very shiny. The same pattern of scratches and their depth are fairly consistent across the whole edge surface. I just don’t want to ruin the edge my trying to polish out the scratches…

Bill

[Anonymous]

I ordered a Low angle adapter on Thursday, looks like I’m getting it tomorrow and want to try a double bevel. Its suppose to rain tomorrow so I’ll be doing some experimenting with the double bevel and some dry stropping. Should be fun.

[wickededge]

I usually wet my leather strops with a light misting of rubbing alcohol. I like how it makes the leather grab the steel as I’m stropping. It seems to work best with strops that are well used, with lots of tiny metal filings embedded in the leather so that the surface looks black. With balsa, I also wet the strops but for a different reason – the paste seems to cake on the surface and flakes off when it’s dry. I think the alcohol breaks down the emulsion of the paste and it’s more readily absorbed into the balsa and less comes off on the knife.

-Clay

2 users thanked author for this post.

CliffCurry

[Anonymous]

Thanks Clay. I’ve tired both alcohol and a water mist. I think the alcohol flashes off, but the mist last much longer, but I’m not sure if the ease of motion makes for a poor polishing media using   water mist.  As  simple as I originally thought, this discipline is becoming more complex, the more I learn.

Everyone on this forum is very helpful, but not everyone is an expert, so its possible to be lead down the wrong path by someone willing to help but someone is id just feeling their way. Much like my O ring suggestion, which I still use because I don’t know any better. It gives me a place to start. For some reason the sharpie method is not as easy.. because the edge is rough, the sharpie stays in the low points of the surface scratches even after the stone removes the upper level of scratches making it hard to see a clear picture… if the edge was mirrored first, and then a sharpie applied, it would remove all of the black , giving a clear witness line. but with the highs and lows of my edges.. all of the low point of the edge surface still shows a black.

[Anonymous]

When I am stropping should I be feeling some resistance ? IM thinking too much pressure will cause scratches, and not enough pressure will not polish the edge.

[wickededge]

Anonymous wrote:

When I am stropping should I be feeling some resistance ? IM thinking too much pressure will cause scratches, and not enough pressure will not polish the edge.

I like to feel quite a bit of resistance when I’m stropping. My hypothesis is that once there are adequate metal filings embedded in the leather, along with the micro-abrasive, you start getting the best of abrasion and burnishing together. I believe that the ‘stiction’ helps improve the burnishing action, which really helps with polishing. The alcohol makes my strops grip the blade much more aggressively, creating more ‘stiction’.

All that said, I’m busy experimenting today with stropping (and with lapping films) and starting to unlearn some of what I thought I knew…

-Clay

[Anonymous]

Its a wise man who can step back and consider alternatives to what has previously been accepted as correct. Revisiting old practices with slight corrections can expose different results. If we did not do this, we would all be still listening to 8 track tapes. : )

Sometimes slight correction can be positive or negative, its the positive result of experimenting which can alter your course to a better final destination.

My 58 Corvette got 10 miles to the gallon and produced 270 Horse power, My current Corvette, gets 33 mile to the gallon in 6th gear @ 1200 rpm ( 2 overdrive gears ) doing 60 mph. And it has 430 HP.

1 user thanked author for this post.

wickededge

[cbwx34]

Anonymous wrote:

For some reason the sharpie method is not as easy.. because the edge is rough, the sharpie stays in the low points of the surface scratches even after the stone removes the upper level of scratches making it hard to see a clear picture… if the edge was mirrored first, and then a sharpie applied, it would remove all of the black , giving a clear witness line. but with the highs and lows of my edges.. all of the low point of the edge surface still shows a black.

Don’t quite get this… If you’re not removing the grind marks (scratches) completely then you’re not done with that stone.

Maybe a picture would better describe what you mean?

[Author]

Posts