KnivesPlus strop block vs. Flex cut gold?

D

d.weglarz13

Joined
Jun 4, 2008
Messages
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Hey guys. Few questions. So, wondering how the two compounds compare, especially when used on the same material (wood, leather, etc.). I have searched, and haven't found the answers so far. For those of you that have used both, please tell which you like better and why, or how they match up against each other.

Is the green knives plus strop block compound the same as the Bark River stuff on the DLT site?

I would like to make some strops out of good leather, maybe kangaroo, and I prefer harder rather than soft backings. But for lets say after a 2000 grit stone right to the strops, would you guys recommend the green that comes with the KnivesPlus strop block, or the flex cut gold that so many people rave about?

Which compound gives more refined of an edge basically.

Still considering a middle ground between the stone and strops, but so far this works well for me for working edges. Any thoughts on this?


Thanks for any help, searching the threads with the hundreds of different compounds (stick, CBN, diamond, etc.) is getting to be tiring. I appreciate any opinions.


dave
 
The green compounds are generally chromium oxide. Good polishers. Flexcut I never found to be particularly effective from a sharpening aspect. Polishes quit well though.

4 micron or lower CBN may be what your looking for. That's pretty much all I use anymore.

The Bark River compounds, black and white, are superior to other stick offerings I've sampled over the years. All this is subjective of course.

Kangaroo would be a good choice for you.
 
Probably shouldn't be responding as I have no experience with the Knives Plus strop block, but Flexcut is my most recommended compound for most uses. It can make a very bright/borderline mirror finish on a softish backing, and a bright/slightly hazy finish on a harder backing. Stuff works very well in my experience and applies well over a lot of substrates.
 
I too have good experience with Flexcut. I got my first freehand push cut on newsprint after I started using it. My understanding is that it contains a wider range of abrasive sizes. Most green compounds tend to be somewhere around 0.5 micron, although I don't know about the KSF specifically.
 
Here is the specs I dug up on Flexcut Gold: .3 - 6 micron measured, most between .5 - 5 micron, with smaller being higher %

I love Flexcut Gold. I use it and the Stropman compounds (mostly black and white) for all my stropping needs.
 
Thanks guys. Been really meaning to do some experimenting lately, and really curious about these two. I appreciate the info. I'm going to try both, on some different backings and see how they do on some different steel.

Do you guys feel it's an acceptable jump from a 2000 grit waterstone to the strops like I have been doing? Or should I add another step if it's necessary?

Thanks again for the replies.
 
d.weglarz13 said:
Thanks guys. Been really meaning to do some experimenting lately, and really curious about these two. I appreciate the info. I'm going to try both, on some different backings and see how they do on some different steel.

Do you guys feel it's an acceptable jump from a 2000 grit waterstone to the strops like I have been doing? Or should I add another step if it's necessary?

Thanks again for the replies.
Click to expand...

I would want to go at least to a 4k or maybe even a 6k. You can use it following the 2k, but is a big jump and you're liable to have some loss of acuteness(?) at the apex.

Stropping off a 2k, I'd just wrap a sheet of paper around a dry stone and smear a small amount of waterstone mud right on the paper (not more than can immediately be absorbed into the paper without disintegrating) - strop on that. You can actually do that off the 4k, 6k etc and maybe not even need honing compound, depending on the finish you're after.
 
Add me to the "likes and uses Flexcut Gold" category.


HeavyHanded said:
I would want to go at least to a 4k or maybe even a 6k. You can use it following the 2k, but is a big jump and you're liable to have some loss of acuteness(?) at the apex.
Click to expand...

Why??
 
At 2k there is still a fair amount of variation in line across the edge (different waterstone brands notwithstanding). Every one of those high points acts as a stress riser, a higher spot where pressure will be more concentrated than the surrounding. Think of it as a region where overall density as a cross section is lower than on a more highly refined cross section of edge, taken as a sample of length. Not to get too confounding, but there are voids where the scratch pattern has gouged into the steel, and these carry right to the edge.


These high spots get worked down first, resulting in a broadening of the angle.

A lot of factors will play into this - obviously if your strop surface has zero elasticity (like a polishing grade waterstone) there will be less pressure spiking on the high points - they get worked down at the same rate as everything else. Use of very light pressure and very limited number of passes will also reduce pressure spiking. As the strop surface becomes more conformable, and/or the number of passes increase, the more concentrated this erosion along the apex will be.

All other things things being equal, if the abrasive on the strop is larger relative to the scratch pattern in the steel there will be less tendency to round (though still present). As the abrasives become finer, it helps to have a more uniform edge line to begin with - think of it as lateral resistance to abrasive erosion.

To see a notable increase in the brightness of the edge coming off a 2k JWS implies a bunch of steel being polished off and a good chance of apex angle increasing...

IMHO/YMMV
 
HeavyHanded said:
At 2k there is still a fair amount of variation in line across the edge (different waterstone brands notwithstanding). Every one of those high points acts as a stress riser, a higher spot where pressure will be more concentrated than the surrounding. Think of it as a region where overall density as a cross section is lower than on a more highly refined cross section of edge, taken as a sample of length. Not to get too confounding, but there are voids where the scratch pattern has gouged into the steel, and these carry right to the edge.


These high spots get worked down first, resulting in a broadening of the angle.

A lot of factors will play into this - obviously if your strop surface has zero elasticity (like a polishing grade waterstone) there will be less pressure spiking on the high points - they get worked down at the same rate as everything else. Use of very light pressure and very limited number of passes will also reduce pressure spiking. As the strop surface becomes more conformable, and/or the number of passes increase, the more concentrated this erosion along the apex will be.

All other things things being equal, if the abrasive on the strop is larger relative to the scratch pattern in the steel there will be less tendency to round (though still present). As the abrasives become finer, it helps to have a more uniform edge line to begin with - think of it as lateral resistance to abrasive erosion.

To see a notable increase in the brightness of the edge coming off a 2k JWS implies a bunch of steel being polished off and a good chance of apex angle increasing...

IMHO/YMMV
Click to expand...

Thanks for the reply. That to me doesn't seem like that is a very significant change in angle, not sure if it would even be measurable in cutting, unless it was a delicate cut, (then not sure you'd stop at 2K to begin with). I suspect you'd get more benefit from the stropping of the 2K edge, then loss of the angle change, unless it's bigger than I'm imagining, or maybe you're thinking a lot of, (like powered?) stropping.
 
cbwx34 said:
Thanks for the reply. That to me doesn't seem like that is a very significant change in angle, not sure if it would even be measurable in cutting, unless it was a delicate cut, (then not sure you'd stop at 2K to begin with). I suspect you'd get more benefit from the stropping of the 2K edge, then loss of the angle change, unless it's bigger than I'm imagining, or maybe you're thinking a lot of, (like powered?) stropping.
Click to expand...

It all depends, you may be right on. In my use, the loss of tooth combined with the loss of angle at the edge I tend to notice pretty readily. If only a few passes I cannot imagine any issues. I wouldn't want to polish it up too much from a medium finish without carefully managing the variables, is easy to loose a handful of degrees per side if one overreaches. Over time it becomes even more apparent.
 
Thanks for the replies guys.
@HeavyHanded I have learned a lot from you over the years so thank you.

I was thinking the kangaroo and also balsa, and trying both compounds on them. I prefer a hard backing on my strops, and have kind of been accustomed to leather over the years of using them.
I am also going to try some regular thick veg tanned shoulder and case it nice and hard first to play with different results.

I have been going from my 2000 grit shapton glass to the strops because it seems to work great for me if I lighten the pressure as I go with the stones. I usually go dmt bench stones course, fine, shapton glass 1000, glass 2000, then strops. This for me gives a nice toothy but super sharp edge free handing all the way.

Very open to improving results though.
 
I have the knives plus strop block. Works pretty well but I'm not super into stropping. I've had it since summer 2011 and it's still going strong.
 
Anybody else use Herbs Yellowstone? It's fairly popular with woodworkers and the straight razor guys, but never see knife guys talk about it. I've never used flexcut, but I like Herbs way better than green paste.
 
Never heard of the Herbs stuff. Gonna look up a little about it though. Thanks.

Still trying to figure out if the green on the strop block is the same as bark river, strop man, or something different.
 
My understanding is all the green pastes are close enough to call them the same. If I am wrong I have never seen anyone claiming it.
 
Just add the 4K Glass stone and a good piece of leather, horse or Roo is the top choice, just don't put any compound on them.
 
Jason B. said:
Just add the 4K Glass stone and a good piece of leather, horse or Roo is the top choice, just don't put any compound on them.
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Hi Jason, and you also I have learned a lot from, back when you were still Knifenut haha. BTW, please don't ever take those links off your sig line. I have been going back to them for years now whenever something seems off with my free handing. So, can I ask why not use the compounds?

I am trying to put a "system" together, where I was considering another stone like the 4k, then go to a good hard strop with whatever compound I find is best for my use, then go to a bare horsehide or something.

Why do you recommend no compound? Is it because after the 4K, the abrasives in the compound will be too large to get good results off the stone? I don't mean to ask so many questions, but been studying this stuff for seems like forever now, and still have much to learn.

Again guys, I appreciate all the help.

dave
 
The 4K Glass stone yields a very sharp and somewhat toothy edge but the best thing about it is the ability to produce an edge will minimal burr. It takes the 2k edge to the next level and cleans off that pesky burr the 2k tends to produce. Final sharpness hovers around treetopping and if you do your part stropping is not really needed.

Because it cleans up the edge so well you can take advantage of the natural polishing characteristics the leather offers. Instead of using compound you let the leather enhance the edge you have produced, this cleans up any burr you might have missed while not over polishing the edge like compounds tend to do.
 
Wow, thanks Jason. Again, you and some others here I have been lucky enough to learn a lot from. Thanks for all of it.

For the bare leather, would you recommend horse, kangaroo, regular cow veg tanned, etc? I know you used to buy your leather from a sharpening company, can't remember, but wondering more in general what would be best. I will also be "casing" it nice and compressed, hard, if that makes a difference with the leathers.

dave



EDIT: As far as a 4K or better stone, what would you recommend? I was thinking another Shapton Glass 4K, but now I am kind of leaning towards something like a Kitayama 8K lmao. Really intrigued by that stone. Is that too much of a jump? Should I stay in the 4K-6K range after the 2K glass?

I feel perhaps I wasted money getting the 2K. It gives me a great working edge though for cutting rope, stuff like that. But most guys seem to go from 1K up to a 4 or 6 right away. Just curious, still have a lot to learn I know.
 
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