Polishing mild steel


Cliff

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Anyone have metal knowledge that I can yank out of your brain and utilize? To the best of my limited knowledge, there are maybe 4 ways of polishing mild steel - bench grinder, air/angle grinder, dremel, and sandpaper.

I have no clue what is best, I just know I need it to be cheapish. Buying a bench grinder appeals to me because I will want one at some point to grind tools that require it. I suspect this will not happen often. 

I'm looking at this at the moment: http://www.homedepot.com/p/DEWALT-6-in-150-mm-Bench-Grinder-DW756/203164097

Not sure if I should get a slow speed one or not. I found a thread from a while back that Eric started on this but his price range was about triple what I'm looking to spend and he had different requirements with the turning tools. 

I also saw an intriguing video with an air grinder, using scotch-brite pads but I couldn't find these scotch-brite pads for sale online that go with 1/4" air grinder. 

Anyway, appreciate any knowledge someone could drop on my lap about this. My google results are a bit confusing, as they assume a level of knowledge that I don't really have concerning metal.

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You looking for stuff like this ?

http://www.nortonindustrial.com/uploadedFiles/SGindnortonabrasives/Documents/Catalog_PDFs/NortonCatalog-NonWoven-Discs(2).pdf

I have used it with a cheap HF air drill and gotten ok results. Those air drills do gobble up the air so go another route if your compressor is small. Or work in small bursts then wait for the pressure to build back up.

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Just like wood. The higher grit you sand the smaller the scratch, the easier to polish out. Just like rubbing out a topcoat. 

 

So sand the steel to 600 grit or higher. I have a bench top grinder with a buffing wheel. What I do is load the wheel with automotive rubbing compound and polish away. You want the wheel to turn super fast.  A drill motor is handy with a small buffing wheel for hard to handle pieces. 

 

From time to time as your wheel becomes loaded with compound and gets nasty. Take the back end of a box wrench or big screwdriver and clean the pad. It can be a dirty job polishing steel. I'd suggest you remove the buffing operation outside your shop so not to contaminate the wood stuff.

 

-Ace-

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Cliff, is there a particular object you need to polish? Size and shape may dictate how practical a grinder will be. Whaterver the tool, be sure to progress through the grits in small steps. I sometimes hone with sandpaper, and find that the surface has a nice shine at 2000 grit, but really looks mirror-like only after stropping with "white rouge" compound. Just saying that multiple media may be required.

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7 hours ago, wtnhighlander said:

Cliff, is there a particular object you need to polish? Size and shape may dictate how practical a grinder will be. Whaterver the tool, be sure to progress through the grits in small steps. I sometimes hone with sandpaper, and find that the surface has a nice shine at 2000 grit, but really looks mirror-like only after stropping with "white rouge" compound. Just saying that multiple media may be required.

These

20160507_112742.jpg

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