Metal polish paste dulling the edge?

L

lalilulelo

Joined
May 26, 2008
Messages
104
Hi guys, I have noticed that whenever I use Flitz metal polish on the edges of some of my knives, the edges would go from shaving sharp to so dull that it wouldn't even cut paper after the polishing

The funny thing is this doesn't seem to happen to all my knives, the Busses and knives made of A2 do not seem to get affected at all, or maybe not to any extent that is noticeable, but Cold Steel SK5 and some other carbon steels usually would have their edge taken off

I am not using any sort of power tools, just the microfibre towel and the paste, which was advertised as non-abrasive, so I honestly have no idea how something like this could happen.

Maybe there is already rust developing on the edge at a microscopic level, and Flitz wiped them out all together along with the tiny bit steel and caused the edge to lose its cutting capability? but I have tested these knives right before polishing , and they certainly did not cut like they had rust on their edges.

Or Maybe Flitz is actually mildly abrasive and by polishing the edge I was actually removing steel and rounding it?

Do you guys have any similar experience with Flitz metal polish?
 
Te issue might be in using a microfibre cloth!
I use flitz on strop made from a paint-stirring-stick with jeans(or some fabric tape, works equally well) glued/stuck on it.
This gives me the sharpest edges I ever had!!
Very light pressure whlie using the strop is the biggest secret for a razorsharp edge.

Good luck
 
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Flitz paste is abrasive (aluminum oxide, at ~3 micron particle size). At that small size, many polishes are advertised as 'non-abrasive' for most materials. But even Flitz's own site recommends not using it on gold-plated or silver-plated items, because even the small abrasive particles can remove the soft metal plating.

I don't have any worries about the Flitz causing a problem. I often strop with Simichrome, which is a similar product with aluminum oxide at ~8 micron particle size; it works great. The dulling is more likely due to stropping on too soft material (the microfiber towel), and/or at too high an angle, and/or too much pressure. The softer the stropping surface, the greater the likelihood of rounding over the edge with any compound, or even with none. Try stropping on thin, firm leather, or just 2 or 3 sheets' thickness of paper instead, like newsprint, printer/copy paper, phone book, etc. Use the paper on a hard backing like glass or hardwood.

Edit:
One of our other members recently contacted the makers of Flitz & Simichrome, to get specifics on what type & size abrasive is used in these products. Here's his thread:
http://www.bladeforums.com/forums/s...d-semichrom-msds-info?p=10650299#post10650299
 
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Ahhh, no wonder, thanks guys, that was way more information than I expected, and it sure clears up a lot of my questions.

I think I will take care when using Flitz from now on, maybe simpler and softer steel like SK5 or 1095 are more easily affected by these tiny abrasives, a few rub and the edge is gone, while harder steels tend to resist them better.

Do you guys think it will take some serious sharpening to fix an edge dulled by Flitz on a Sharpmaker? mine is coming tomorrow, and I have a few dull knives sitting around thanks to Flitz and my own carelessness.
 
lalilulelo said:
Ahhh, no wonder, thanks guys, that was way more information than I expected, and it sure clears up a lot of my questions.

I think I will take care when using Flitz from now on, maybe simpler and softer steel like SK5 or 1095 are more easily affected by these tiny abrasives, a few rub and the edge is gone, while harder steels tend to resist them better.

Do you guys think it will take some serious sharpening to fix an edge dulled by Flitz on a Sharpmaker? mine is coming tomorrow, and I have a few dull knives sitting around thanks to Flitz and my own carelessness.
Click to expand...

The Sharpmaker should quickly get it sharp again. The small abrasive particles in the Flitz can't do too much damage to a steel knife blade, especially on a soft backing.

For stropping in general, I'd highly recommend going 'low & light'. In other words, make sure your angle is conservatively low, and keep pressure very light. That'll make the most difference of all, regardless of the abrasives used or the steel being sharpened. All the more important on relatively 'soft' steels like 1095. It can take a great edge using Flitz on a strop, but you need to be gentle with it. It shouldn't need too many passes on the strop, if the edge is fully 'ready' for stropping, i.e. fully apexed and most of the burrs/wire edges cleaned up.
 
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Btw....
A friend recommended using flitz on a leather strop!!!'
He made a great recommendation, its really worth a shot!
 
Obsessed with Edges said:
The Sharpmaker should quickly get it sharp again. The small abrasive particles in the Flitz can't do too much damage to a steel knife blade, especially on a soft backing.

For stropping in general, I'd highly recommend going 'low & light'. In other words, make sure your angle is conservatively low, and keep pressure very light. That'll make the most difference of all, regardless of the abrasives used or the steel being sharpened. All the more important on relatively 'soft' steels like 1095. It can take a great edge using Flitz on a strop, but you need to be gentle with it. It shouldn't need too many passes on the strop, if the edge is fully 'ready' for stropping, i.e. fully apexed and most of the burrs/wire edges cleaned up.
Click to expand...


David, thanks for your advise, I would definitely give the stropping a try once I am able to get the edge back on these knives.
 
Flitz makes a microfibre cloth to use with their polish. Just make sure you use a clean part of the cloth to wipe off the polish. Stropping with Flitz is a great idea.
 
I've noticed this as well, usually if I just strop afterwards the edge is restored. I don't use flitz all that much anymore because the finish it leaves doesn't look right to me. I prefer just using my .5 CrO paste.
 
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