mirror polishing blade and bolsters

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sharpandsafe

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Feb 25, 2011
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I have a case abalone lockback that I got my dad for his birthday. There are some light polishing marks (scratches) on the blade and bolsters. In addition to touching up the factory edge, I want to buff out any marks on the blade and bolsters. How can I do this? Would rubbing with chrome oxide on a microfiber cloth or felt pad be a solution? Where can I get high-quality chrome oxide? Both japaneseknifesharpeningstore.com and chefknivestogo.com seem to be out of the stuff.

Thanks for your help.
 
Bill DeShivs said:
Simichrome metal polish.
Google it.
Click to expand...

:thumbup: Good stuff. Been using it quite a bit lately, for polishing bolsters and edges. Works great as a stropping compound, too.

Edit:
As for scratches, if they're a little too deep for compound/paste to remove, wet/dry sandpaper will handle those. Start with a finer grit, like 1000 or so. If it's too slow, take a step down in grit (600/800) and try that. Most scratches can be taken care of at 400 grit or higher. Heavier dents/dings might need something down around 220/320. Once the scratches are cleaned up, go back up the grit progression, through 1000 or 2000. Then polish with the Simichrome. Works like a champ.
 
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Bill DeShivs said:
Simichrome metal polish.
Google it.
Click to expand...

Okay, I will get some of this, but now I have some other nerdy questions. According to the MSDS for Simichrome, Simichrome is basically a combination of aluminum oxide (abrasive) and ammonium oleate (surfactant). How do the properties of aluminum oxide differ from chromium oxide for polishing metal? I am assuming, based on the information available at www.caswellplating.com/buffs/buffman.htm that aluminum oxide is softer. It is recommended for polishing nickel plating (bolsters) but not for stainless steel. I am assuming that the SS in the case knives is soft enough to respond to buffing with aluminum oxide. Is this correct? Is the particle size of Simichrome really small enough to create a flawless mirror finish without swirls or polish marks?

Thanks!
 
Aluminum oxide might or might not be a little 'softer' than chromium oxide, but it's still MUCH harder than steel. Aluminum oxide is also the same stuff used to make ceramic hones (also known as 'alumina ceramic'), and it's also used in a wide variety of other abrasives (like some types of wet/dry sandpaper, and grinding wheels, both of which are used extensively on steel).

Another thing to consider. Most chromium oxide is rather small (0.5 micron). In the case of aluminum oxide, it's particle size is generally larger. Effectively, it can remove more metal faster (as in polishing steel), due in larger part to the size of the abrasive particles.

Edit:
Here's a link to a 'Mohs' hardness chart. Note the relative hardness of 'green chromium oxide' (8.5 moh's) and 'fused alumina' (also known as aluminum oxide, at 9.2 moh's), versus 'knife steel' (at 5.5 moh's). Diamond is the hardest, at 10 on the Moh's scale.

http://sharpeningmadeeasy.com/mohs.htm
 
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"Is the particle size of Simichrome really small enough to create a flawless mirror finish without swirls or polish marks?"

Yes, it is. But the underlying surface has to be properly prepared first.
 
Not on point however I have used Simichrome on SS hanguns for years..no pearl grips..yet. I use on my working plain finish blades. Product does a nice job and goes a long way..Germans do make good stuff.
 
Okay, I'm bringing this back up because I tried the Simichrome in this application and was disappointed. The Simichrome did, indeed buff out the scratches, but it left it's own scratches behind - kinda' like a very light satin finish - you can see the scratches in the light at the correct angle. I tried buffing using felt and microfiber and got the same result with both. I tried the microfiber dry and got no scratching, so I know it must be the compound that is doing the scratching.

I have ordered some other compounds from Handamerican to try - 0.5 micron chromium oxide and 0.25 micron diamond spray. I have also ordered several other buffing wheels for the dremel including leather, cotton string, cotton muslin and loose felt. What do you think will work? I am also thinking about getting some jewelers' rouge to try on the bolsters because I have read that nickel is soft enough for the red rouge to work on, and I understand that the red rouge typical particle size is 0.1 micron.
 
sharpandsafe said:
Okay, I'm bringing this back up because I tried the Simichrome in this application and was disappointed. The Simichrome did, indeed buff out the scratches, but it left it's own scratches behind - kinda' like a very light satin finish - you can see the scratches in the light at the correct angle. I tried buffing using felt and microfiber and got the same result with both. I tried the microfiber dry and got no scratching, so I know it must be the compound that is doing the scratching.

I have ordered some other compounds from Handamerican to try - 0.5 micron chromium oxide and 0.25 micron diamond spray. I have also ordered several other buffing wheels for the dremel including leather, cotton string, cotton muslin and loose felt. What do you think will work? I am also thinking about getting some jewelers' rouge to try on the bolsters because I have read that nickel is soft enough for the red rouge to work on, and I understand that the red rouge typical particle size is 0.1 micron.
Click to expand...

I'd be willing to bet, the 'satin' scratches aren't due to the simichrome (the abrasive in it is a lot finer than that). More likely due to grit or other contamination in the rag or whatever medium was used to apply the paste and/or buff afterwards.

The other possibility is, the surface wasn't prepared for the polish. The downside of polishing is, it'll highlight any imperfections present before the polish was applied. It'll make 'em really stand out.
 
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Just a quick update here.

I tried several different compounds on leather, microfiber and felt buffs. I was only able to get the surface I wanted with 0.25 micron diamond spray on felt. All the other compounds left visible marks or "haze". I have also learned that even for very small scratch removal, it is essential to start with a larger grit and move to smaller.

For the record, the Simichrome was second best only to the diamond. The Simichrome has a very small grit size indeed. I just think the effect I was looking for meant I had to go to an even smaller grit.
 
What about a Flannel wheel turning at 600 to 800 RPM and using jeweler's Rouge. I want to start learning how to do this. Could anyone offer some advice Possibly. P.S. I have a dremel Tool but I can't seem to polish very well with that little of a wheel. Oh yea I don't know what speed to polish anything at either. Any Suggestions
 
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