# mirror polish on SS and Carbon Steel blade



## CNR (Feb 6, 2013)

Hi everyone,
Although i have several good knives (mostly folders), i usually EDC one of my opinels which i like to customise them (working the handle, etching the blade) lately i started to try to polish the blade by sanding it all the way to 3000 grit and then finishing with a polishing cream, the result is nice as long as you don't look at the blade under the light, it's not really close to "mirror", i mean that you can see your face on the blade but under the light there are many many hairlines (propably from sanding) which won't seem to go away, does anybody know if i should insist more with the sandpaper or Polishing cream, am i using the wrong cream or am i missing a whole step here ?


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## gollum (Feb 6, 2013)

you are revealing the deep scratches that were always there.
most production knives are ground and prepared using 120 or 180 grit
then a quick satin finish to give it a reasonable finish (visually)
it is quite durable,hides fingerprints and machine/finishing irregularities

proper mirror finish is far more involved
going through at least 5 or 6 grades of grit size to fully remove previous grit marks
correct technique is to cross grain sand each step


also the deeper grit has a tendency to get mushroomed over when going to the next grit 
this is because the finer grades clog quickly and dont cut the steel but rub it over and kind of mashes the surface instead of clean cutting
finally alot of steels are not very good at getting a proper mirror finish,they will look waxy or grey 
this is about the chrome content but also the way it has bonded to the other exotic alloy content and the hardening process

it is very complex metallurgy... 
[h=3]_Metallurgy_ [/h]


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## gollum (Feb 6, 2013)

thought I'd add if you are determined 
step 1 would be hand rub with 320 grit until it is fully uniform in appearance 
then cross grain sand it again
then go 600 grit same process
then 800,1200 probably just one way would do
you can go to polishing buff using black polishing compound first then white and final green


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## CNR (Feb 7, 2013)

Hey gollum, thank you so much for all this info, i know nothing about metal working so please bear with me for a while :



> the deeper grit has a tendency to get mushroomed over when going to the next grit



I'm not sure i understand what do you mean ?
You mean i must use "fresh" sandpaper every little while in finer grades to keep it working ? 
I used 400, 800, 2000 and 3000 grit, 



> ..then cross grain sand it again...



If you mean sand it on a perpendicular direction to the one i was sanding it before, that's very difficult, blade is narrow, i allready cut a finger and stabbed a thumb trying to  , any other option ?
I even tried an electric drill with polishing head mounted but it's very difficult to align with blade's surface and very easy (as i found out) to "catch" and destroy the edge. 



> black polishing compound first then white and final green



What is that ? What kind of compound ? can you name a brand so to know what to look for ?

Thanks a lot


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## gollum (Feb 9, 2013)

fresh sandpaper will feel like its cutting into the surface,thats because it is.
as it loads up with gunk it stops cutting and doesn't make for good surface removal

I also would not perform any of these actions with a sharp blade due to the risk of slicing yourself

you could gently run a 600 grit lightly on the edge if you really want to continue
...sharpening the blade is your final task


try using a solid block of rubber or brass and wrap the sandpaper around it (once) and rub the block on the blade,support the blade on a piece of wood or hard rubber,
use water or metho to lube/wash while working



jewellers rouge is a commonly found buffing compound
if you search jewellers or knife supplies they will list it along with the colour and grade you want

usually black is coarse and green is finest( also pink and white depending on brand)
these are best used on a proper polishing mop (cotton or flannel)
it is also a potentially dangerous action,be sure you are familiar with polishing practices.
lead the work into the mop using sweeping motions etc
keep it cool and don't load up your work etc

if you have no idea what I'm referring to try looking at some tutorials on the blade forums or you tube

I guess overall you are looking at a lot of work to get the result you want
usually blade steel is worked to a nice fine grade and then hardened ,leaving minimal work to finish

hope this helps


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## CNR (Feb 10, 2013)

Thank you so much gollum :thanks:


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## gollum (Feb 11, 2013)

CNR said:


> Thank you so much gollum :thanks:



most welcome sir


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## lintonindy (Feb 11, 2013)

Excellent thread and excellent information Gollum! I learned a lot from this as well. I also use a buffing wheel with black then brown then white compound but was unaware of the green compound. I will have to pick some up for my buffing jobs. Thanks again guys!


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## gollum (Feb 11, 2013)

lintonindy said:


> Excellent thread and excellent information Gollum! I learned a lot from this as well. I also use a buffing wheel with black then brown then white compound but was unaware of the green compound. I will have to pick some up for my buffing jobs. Thanks again guys!



cheers lintonindy, btw I use the green compound on a flannel buff for finishing
white and pink on my loose cotton buff and coarse black compound is really aggresive if you use the sewn denim buff
(blends brass really well

like this







bear in mind the polisher is the most dangerous tool if it grabs your work
always lead the work in and use proper technique and safety


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## CNR (Feb 12, 2013)

> bear in mind the polisher is the most dangerous tool if it grabs your work



? What do you mean by this ? What is the danger ? is this compound toxic or corrosive in some way ?


EDIT: Oh, you're propably talking for a high speed revving polishing machine, right ?


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## gollum (Feb 12, 2013)

yes 
its one of the most dangerous tools to use

a lot of polishers are high rpm and can easily grab the work
I have lost small round things before,being too hard to grip
don't want to think what a knife would do


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## lintonindy (Feb 12, 2013)

You are right they can be very dangerous! I use a craftsman bench grinder with extensions and a rough and soft wheel, mostly to polish my motorcycle parts. I did try my knife once and lost it. It flew right in to the drywall and stuck so only one side got polished that day. I had to step away, drink a beer, and calm down after that episode. I told my self no more polishing sharp objects. Now my titanium light or my wedding ring every once in a while that's another story all together. Good luck to all and BE CAREFUL!


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## gollum (Feb 12, 2013)

LOL
the polisher is a great tool 
I just restored a CB450 ('71) and used it to shine up lots of parts

things like rings can be looped through some locking wire and still carefully polished but it allows better coverage 

I did a knife with so many bits jutting out it was a nightmare to polish

I just did very light sweeps and held on very firmly

btw I have always used 5inch by 2 inch wide mops they are much nicer to use than the more common (and cheaper) 1/2 or 1 inch wide ones

a bit harder to find but worth it 
I also use a 4inch x 2 inch wide flannel mop for finishing 
it has a superior finish than cotton.

haven't seen them for sale in ages 
let me know if you find one

cheers Jason


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## lucca brassi (Feb 21, 2013)

http://www.fronius.com/cps/rde/xchg...us_international/hs.xsl/79_18798_ENG_HTML.htm

http://www.fischione.com/product_support/model_110_application_notes.asp

http://www.diyprojects.info/bb/ftopic42795.html

http://www.diybanter.com/metalworking/16364-electropolishing-recipes-version-two.html


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