Blade Polishing

T

tapedeck74

Joined
Jul 24, 2006
Messages
475
Hi there folks,

I'm polishing up a blade (mild stainless), and I'm wondering how to get a more mirror finish. I went through the range of ultra-fine sanding sheets to get out the scratches and then used (red) polishing compound. The finish is even and looks pretty good.
I polished from tang to tip and when I hold the blade under a light vertically, the finish is mirror. When I turn the knife around so it is horizontal, the finish is satin.
What compound can I use that is fine enough to get out these micro scratches from polishing with the iron oxide? Should I just go at it with a cloth polishing wheel with no compound?
 
Chromium Oxide on a buffer will give a nice shine. Jewelers rouge will give an even brighter shine. Someone said you could use CrO with a Dremel but it seems to me it would come out streaky.
 
Agree about the Dreml, don't use it. Most folks run a Dreml way too fast and even when buffing it's too easy to "burn" in streaks or spots. A soft cotten belt or wheel on a slow power setup with rouge is best. Even better is elbow grease and hand polishing. Also want to mention the grain of the metal will have a great deal to do with the final finish. Some steels are coarser grained and you just can't get a true mirror finish.
 
Another thought came to mind regarding polishing. I'm a ham radio nut and years ago, we used to use Arm and Hammer baking soda with a bit of water and on a glass plate to "grind" down transmitter crystals. A half hour or so of lapping a crystal would raise its frequency a few kilohertz. Anyway, later used this same technique to grind away scratches on eye glasses, watch crystals, etc. Now that you've given me the bug, think I'll try it on a knife. The baking soda is a really fine particle size wise) polishing compound.
 
CW
I wouldn't think baking soda would be abrasive enough for steel or radio crystals. We use it in the jewelry business to clean jewelry, and it doesn't scratch gold, but it will polish it slightly. You can drink soda and water.
Bill
 
Bill, Back in the 40s and 50s, most Ham transmitters were crystal controlled and surplus military crystals were everywhere and dirt cheap. It was common with Hams to remove surplus crystals from their holders and regrind them with baking soda and elbow grease. Honest. I did many of them. Also polished minor scratches from my eye glasses a time or two. Also agree you can drink it, used to be the best remedy there was for a sour stomach.
 
I have been in the two way radio business for many years and I know about crystals! I wear many hats.
I just don't see how sodium bicarbonate can polish quartz or steel. Maybe it can-I'll have to try it, but there are certainly better methods.
Bill
 
What about polishing metal knife handles/scales? I have a Spyderco Police in Stainless and I bought it used and carried it a bit. I believe the handles are aluminum and have several scratches on it but none too deep. I can start with some sandpaper and work my way up just the same as a blade correct? What grit should I start with? The scratches barely snag my fingernail. I have 800/1500/2000 on hand for my auto detail hobby. Is 800 too fine to remove the scratches? I'm sure a pic would help...
 
I'm pretty sure the Spyderco scales are stainless. Use a red or gray Scotchbrite pad, lengthwise on the. This should blend most of the scratches.
If not, 400 grit paper should sand them out. You can go to the higher grits as necessary. Use a sanding block if you can.
Bill
 
I am assuming aluminum as the blade end feels heavier than the handle end when balanced on my finger. I can't check with a magnet since it could be stainless. I'll get some Scotchbrite and 400 grit, thanks. Then I'll move to my finer grits and prob invest in a bench grinder and some polishing/buffing wheels. Thanks Bill.
 
Almost all stainless is still magnetic to some degree.
Bill
 
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