How to polish a blade?

Kershaws

Kershaws

Joined
Aug 3, 2013
Messages
592
Sorry if this doesn't belong in general discussion, im not sure where to put it
I have a small 2 1/2" 420HC blade that im trying to get a mirror finish with, I have limited resources, only have 2000 grit sandpaper, some polishing cloths, and green compound. I scrubbed the blade with the sandpaper until it got really shiny, then got a microfiber cloth and rubbed green compound all over it, then sprayed Rem-Oil on it to spread out the compound, the rubbed the blade until I got a mirror finish, but when I clean off the blade you can see a bunch of fine scratches and some streak marks, how do I get rid of that and get just a mirror reflection?
 
I would like to know also I done the same thing with my Cold Steel Point Guard. I can't get rid of the fine scratches.
 
Skimo said:
A lot of elbow grease, a flat surface an more elbow grease.
Click to expand...

^^^ this, unless you are able to employ some electrical help elbow grease and a LOT of time is the only way you will achieve a mirror polish.
 
Your going to be rubbing it for awhile, it takes a lot of time to hand rub a mirror polish. Just keep going with the sand paper and you will get.... Eventually.
 
How deep are the scratches? You might need to get coarser sandpaper and gradually work your way down to the 2000 grit, maybe 320-400-600-1000-1500-2000. Hope you have some free time
 
I guess I'll expound a little, I mirror polished a Benchmade 940, it took a significant amount of time over several weeks. First time and I went from 220 to 2k grit and worn out 2k grit with green compound, by hand, every crisp grind line was gone (which I really like, my preference) but I could have done it so much faster if I had seen that video first.

I think 'around the grinder' section has a post showing how Nick Wheeler mirror polishes his blades, I recommend watching it.
 
They are not deep at all, it's on the surface, they look like smudges, you know how you smear fingerprints on the bathroom mirror, that's how it looks like, but doesn't go away, ill just keep rubbin it then with the cloth and green compound
 
Mirror polish is a relative term but, If you want a mirror polish, whatever definition you use, use strips of pristine business card stock with a flat wood backer and diamond paste. Most industrial machine shop websites offer diamond paste, I always always use the U.S. made paste, I've tried foreign stuff and not been happy. Norton makes some good stuff. the orange paste is 3000 grit and will give a pretty satisfactory finish, Yellow (8000) and white (100,000) will give progressively better finishes. Start coarse and work finer in steps. Don't start with coarse and expect to polish out with superfine or you'll grow very tired of rubbing on steel. Change your paper strips frequently.

When you get the blade polished out as best you can, inspect for scratches, if there is a big one or ones, go back one level and start over again, don't waste your time trying to polish out a deep scratch with too fine a media.

Find some way to hold the blade firmly fixed, wood blocks in a vise, whatever it takes make sure the thing doesn't come to life and start flipping around on you while you're rubbing on it.

I always sand with kerosene (use whatever cutting fluid you prefer) with a flat or contoured backer stick down to 1200 grit and then go to orange diamond paste (no fluid). It cuts fast and gives a good initial polish, then if you want go finer still.

Sometimes I think I see a finish polished blade but with one scratch and have to start all over again. patience is a virtue or so I've been told.

There is no need to implement any power tools to attain extremely good results.

Previous advice given by Skimo is good, use lots of elbow grease and be patient! Good Luck!

Ron A.
 
You need to work in a very clean environment too as contamination from multiple sources can rescratch your blade very easily. If it is a folding knife make sure that just closing and reopening the knife does not cause contact between the blade and the frame, scratching the blade. I have an Opinel I polished with that problem.
 
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