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prkaye

Well Known Member
I recently bought a small bench grinder from a hardware store. I removed one of the blue grinding wheels it came with and put a 3m Scotchbright wheel on. I left the other blue grinding wheel on the grinder, thinking I can use it for more aggressive grinding tasks (like smoothing corners of parts I have to fabricate from aluminum angle).

Question - is it OK to use the general purpose grinding wheel on airplane parts? Or is there a chance that the grinding wheel will contain some metal content, and that this could get worked into the aluminum I am grinding, opening the door for corrosion by dissimilar metals?
 
Never - Ever use a grinding wheel on aluminum parts or any non-ferrous material. What will happen is the grinding wheel will load up with aluminum, go off balance and could come apart with disastrous effect - especially if your face happens to be in the way of the flying shrapnel of broken wheel. The part you are trying to smooth will come out with a terrible finish also - having seen the results in high school shop class - the guy got lucky though when the 10" wheel exploded and nobody was hurt. He got thrown out of class for not paying attention... :eek:
 
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Can you use silicon carbide wheels for non-ferrous metal??

From Norton's (wheel mfr) web site:

"The Norton Bench and Pedestal Wheel line encompasses three tiers and two abrasives ? to answer all your deburring, shaping and sharpening needs: aluminum oxide for high speed tool steels and other metals and silicon carbide for non-ferrous metals."
 
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mdredmond said:
Can you use silicon carbide wheels for non-ferrous metal?? "QUOTE]

Yes - silicon carbide wheels are intended for that purpose, but in my machine shop experience it was used to put the fine finishing touches on dimension, not take alot of material off to shape. If you do use it make sure to keep the part and wheel wet with LPS, WD40 (I've even heard of crisco being used) so the wheel stays clean. Once melted particles of aluminum get into the wheel the only way to get it out is to dress the wheel with a carbide dressing stone. What we found in the end is that the coarser ScotchBrite wheels did the same job with alot less hassle for low tolerance work. We still used the silicon carbide wheel on the surface grinder though, but that was for precise dimension that we are not after here.
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The best tool to use for any work with not ferrous metals is a belt sander. I use a 1" wide Delta benchtop belt sander. I use coarse , medium and fine abbrasive belts as necessary for the job at hand. If a belt tears the worst that can happen is it will make some dust. Grinders are dangereous.
 
The best tool to use for any work with not ferrous metals is a belt sander. I use a 1" wide Delta benchtop belt sander. I use coarse , medium and fine abbrasive belts as necessary for the job at hand. If a belt tears the worst that can happen is it will make some dust. Grinders are dangereous.
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I bought a Delta 1" vetical belt sander with the small (5"?) disk sander on the side. Seems like a good tool. Maybe I'll slap a coarse scotchbrite wheel on the other side of the grinder.
 
I have a 3M scotchbrite light deburring wheel on one side and a 3M cut and polish wheel on the other side. They are both 6 inch X 1 inch wheels and do a great job. All other grinding and smoothing operations are done with air tools with assorted sanding and polishing wheels. The 1 inch belt sander is also a great tool. One little piece of advice would be if you have the little tool rests on the grinder attached keep them very close to the wheel at all times or remove them. The gap between the wheel and the tool rest is what usually gets people hurt. I see no reason to have them on for our purpose anyway. They just get in the way.
 
abrasives for aluminum

Phil
In general, the abrasive used to make most homeshop type grinding wheels is for grinding steel (aluminum oxide) Don't let the name fool you, aluminum will clog the bejabers out of your wheel and you will have a mess trying to get your parts smooth. Contact any good industrial supply company in your area and request info.on silicone carbide wheels for grinding aluminum. Their grinding wheel people will advise you on grit size and wheel hardness for your intended use. The same applies to disc and belt sanders. Look up Norton in your industrial directory, they are one of the worlds best for grinding and polishing supplies. Doug Bell Sr.
 
Don't forget to wear a mask when using silicone carbide wheels. It is not good for the lungs. It gets in the air much worse than aluminum oxide wheels do. The reason it cuts so good is it breaks down fast and doesn't load up. All that silicone carbide that is breaking down goes in the air. This is assuming you are talking about the common green colored silicone carbide wheels that I use to sharpen carbide cutters.
 
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