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  • Help

    Hello all,
    I find myself seeking help from any one with more product knowledge then I , so that means every one. I have 280'.00 of 304 SS in 1/2” x 2”.00 Flat bar to Polish even before project start / fabrication. 1st question please: I will be using a 6”.00 angle Grinder to polish said materials. I've attempted to find the correct wheel / pad / product and company I can order from, any suggestions what I would use 1st then what product to use 2nd . 2nd. question: My poor attempt / research finds Green compound is what I should use/ I'm again @ such the loss. Understand the material will be 304 SS mill finish so any help direction to take the material from mill finish to a very high luster would buy you a cup of Starbucks. 3rd. Question. Once fabrication has been completed I have to dress the welds. 50% of all the welds are in very tight areas were I can not get above tooling (6”.00 Angle Grinder) in said locations. Suggestions please. And in closing I so appreciate all your time.

    Best Regards,


  • #2
    Re: Help

    if you have no experience in polishing stainless steel and are trying to get a mirror finish , i suggest you do a test piece first and see if that is the type of finish you are looking for .
    i am not trying to discourage you but you should know that ss is not an easy material to work with, you are getting into many many hours of hard labour if you want to get 280 feet of it done .
    to your first question my opinion is that a 6 inch angle grinder is not the right tool for the job , those grinders are just that , they are meant to grind and not to polish.they do have a variable speed and they spin way too fast .
    a 7 inch angle polisher/sander is much better .
    to get mirror finish on ss from mill finish , you probably need to start sanding down from 180 grit then 280 or 320 then 400 or 500 and then probably a 600 , then you could start polishing with a green stainless compound ,if you can not get the sanding lines out with the green compound you have to get a more agressive compound after sanding and before the green or you could try to sand with 800 after the 600 grit.
    for question #3 i would have to see the hard to reach areas , maybe a smaller sander like a 3 inch , cartrige rolls on a die grinder, or a hand held belt sander like ones that dynabrade sells they have a 24 by 1/2 belt but those sanders are expensive


    • #3
      Re: Help

      Do you really mean 280 feet? I hope you are charging a huge price. You said a very high luster. What do you mean exactly? Polishing that much stainless to a mirror finish is an inconceivable amount of work.

      Okay, here goes. I polish a good bit of 304 stainless in my sculpture studio. The first thing to do is to determine what grit of sandpaper to begin with. Assuming the metal is not scratched or dinged, I would think 220 grit would be a good start. Then 400, then 600. You have several things going against you sanding stainless. It's hard (a lot harder than steel), and it eats sandpaper. It takes a lot more time than people think to sand it.

      You said a six inch angle grinder. How fast does it turn?

      For sanding 2 inch flat bar stock I would make a rubber backed sanding pad to fit the sander about 3 inches in diameter. You could make it to use either Hook-It disks or self adhesive disks. 3 inch disks are available but cost a fortune. Buy the paper in 25 foot rolls and cut your own. Buy a lot of rolls.

      You absolutely must sand out all of the 220 scratches with the 400 before going on to 600 or what you will have is nicely polished scratches.

      Get a coarse stainless compound and a fine stainless compound. Caswell sells them. Don't use anything that is not made for stainless. It won't hold up to the hard metal. Use a hard spiral sewn cotton buff. Buffing that stuff could be a nightmare. The buff will be wanting to catch on the edges of the metal and jerk the machine out of your grasp. Putting it on a flat piece of sheet metal will help a lot for that. You will need a machine that turns no more than 3500 RPM for the buffing. A high speed grinder is not good for that.

      You won't believe how much sanding it will take until you try buffing out metal that is not sanded enough and you have to begin again.

      If someone brought me 280 feet of stainless to polish I would head for Texas.