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Bench Grinder for polishing parts

Old 03-24-21, 05:42 PM
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Frenchosa
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Bench Grinder for polishing parts

I have always wanted a bench grinder for polishing parts. I lived many years in a condo with no basement, now I do have a basement and can start to buy some power tools. I see this bench grinder on Craig's list near by and I am wondering if it is adequate to do some polishing.



Do the sides come off to change the wheels?
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Old 03-24-21, 05:57 PM
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really too small for practical polishing., you don't really want those high rpms either. something like this would be a better choice. or a handheld tool
https://www.grizzly.com/products/gri...olisher/t32003
got this guy it works great. https://www.amazon.com/Bare-Tool-Mil...6630189&sr=8-2
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Old 03-24-21, 06:52 PM
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For polishing a common bench grinder is not the first/best choice. Too slow for buffing speed, limited access to the buffer wheel being the biggies. For starting out I might suggest a hand held like a 1/4" (or 6mm) die grinder. If you must get a bench top unit that was intended for grinding then you'll likely be removing the wheel guards to get better access. Position the grinder on the end of the bench too. Andy
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Old 03-24-21, 06:55 PM
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yo0i don't want high rpms the wheels with just fly apart. most big bugging setups are 1750 or so rpms. .
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Old 03-24-21, 07:02 PM
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Thanks for the insight! I think I will pick up that grizzle!
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Old 03-24-21, 07:04 PM
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Originally Posted by Frenchosa View Post
Thanks for the insight! I think I will pick up that grizzle!
if you were closer I would sell you a great etude thats just collecting dust in my shop. I set one up with 4 wheels so you can go from bought to perfect without any changing wheels.
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Old 03-24-21, 07:09 PM
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Originally Posted by fooferdoggie View Post
yo0i don't want high rpms the wheels with just fly apart. most big bugging setups are 1750 or so rpms. .
Polishing is generally done with cloth wheels. Stone wheels (which might fracture if run at too high a RPM) will result in a rough surface. Polishing is a smooth/mirror like surface. If I started with a ground flat surface (and done with a bench grinder like imaged and not a very well controlled specific surface grinder) I would be using hand held sanding cloth in finer and finer grits long before any real polishing begins. For the lugs and such that some builders polish the finest grit cloth used is often around 600 to 1000 grit. The common bench grinder stones are around 50-80 grit as example.

BTW a good technique in prepping for a polishing is to sand each grit step at right angles to the previous coarser sanding. When that coarser sanding surface no longer shows scratches (having been sanded away with the3 finer grit step) you can move onto the next even finer grit step. Andy
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Old 03-24-21, 07:14 PM
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Originally Posted by Andrew R Stewart View Post
Polishing is generally done with cloth wheels. Stone wheels (which might fracture if run at too high a RPM) will result in a rough surface. Polishing is a smooth/mirror like surface. If I started with a ground flat surface (and done with a bench grinder like imaged and not a very well controlled specific surface grinder) I would be using hand held sanding cloth in finer and finer grits long before any real polishing begins. For the lugs and such that some builders polish the finest grit cloth used is often around 600 to 1000 grit. The common bench grinder stones are around 50-80 grit as example.

BTW a good technique in prepping for a polishing is to sand each grit step at right angles to the previous coarser sanding. When that coarser sanding surface no longer shows scratches (having been sanded away with the3 finer grit step) you can move onto the next even finer grit step. Andy
yep cloth soft and firm and the right compound. I found a 12" grit wheel that was about 600 grit. it was great for the bulk of work. you need to watch out for the dust the wheels shred and fine dust and
fibers fly around.
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Old 03-25-21, 08:36 AM
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Originally Posted by fooferdoggie View Post
.... you need to watch out for the dust the wheels shred and fine dust and
fibers fly around.
And having the wheel snatch the work out of your hand if you do not maintain a firm grip. Hand, eye, face and chest protection are advised. I use leather gloves, goggles, a face shield and a leather apron with a thick catalog tucked in. All have taken hits that would have gotten me had I not been protected.
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Old 03-25-21, 09:35 AM
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I spent a few summers working in a plating facility and spent many a hour behind a buffer polishing bumpers and the like. Have fun but take care, anodizing will need to be removed first on aluminum and wear protective equipment.
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Old 03-25-21, 10:07 AM
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Originally Posted by dsbrantjr View Post
And having the wheel snatch the work out of your hand if you do not maintain a firm grip. Hand, eye, face and chest protection are advised. I use leather gloves, goggles, a face shield and a leather apron with a thick catalog tucked in. All have taken hits that would have gotten me had I not been protected.
great add. its amazing how spinning things can yank stuff out of your hands. inflatable drum sanders are about the worst. here is what I used start to finish. but this was mostly on flat surfaces.
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Old 03-25-21, 11:03 AM
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Oh, also make certain that the motor is securely fastened to the workbench with screws or bolts. Clamps and the like can work loose.
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Old 03-26-21, 10:46 AM
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+1 for things flying out of your hand while polishing. If possible make some kind of back stop that can catch little bitty parts that you loose this way. Watch out when you polish brakes or derailleurs. The clamp nut for the brake or shifter cable will often spin off if you didn't tighten it securely and fly into the alternate universe , never to be seen again. (which is why I have trays full off little spare parts on my workbench).
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Old 03-26-21, 11:30 AM
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O.P.,
Bench griders are fine if varible speed...low speed and high torque are what is needed. you will be limited by the length of the shaft when doing larger pieces. I also have a foredom that works well and at times I have used a drill press with a conical buffer to polish parts.
If you are going to use the grinder pictured, you will need to remove the rear gaurds in order to manipulate the parts relitive to the budffing wheel. Cotton wheels are the what to use,if parts are particullary rough, you may need to to fine sand them first. If not red, white and green polishing compounds will get you there.
There are a lot of videos on U-Tube that you will find informative.
Good Luck.
Best, Ben
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