smontanaro 

Sort of only peripherally related to C&V, though it could be...

I have a cheapo (one speed) Black & Decker dual-wheel grinder. I don't use it much (mostly to sharpen lawn mower blades). It's got two grinding wheels. Can I replace one of the grinding wheels with a buffing wheel to expand the tool's repertoire, or is there some reason it wont work (wrong RPMs, for example)?

Murray Missile 

You sure can, I know a lot of people that switch back and forth between grinding stones, wire wheels and buffing wheels on their bench grinders.

dweenk

^^^^ Yes you can!

jackbombay

I'm currently using mine to polish aluminum :-)

Hobbiano 

Yes you can. You can even remove the guard (depends on the particular grinder & only on a buffing wheel) for better access. But be sure to not approach the buffing wheel with the work against the direction of rotation but angled with the direction of rotation so it wont be grabbed by the wheel and thrown (opposite how you would approach a grinding wheel) and always position yourself to one side of the wheel and not in line with the wheel. Grinders and buffers usually run at either 1700 or 3600 rpm and ether is okay. Be careful and wear eye protection and no loose clothing that can be caught by the wheel. Wire wheels always throw off strands of wire so eye protection and standing to the side out of line with the wheel is especially important. The biggest hazard with the buffing wheel is it grabbing and throwing the work, so be aware. Again stand to the side. Grinding wheels can crack and basically explode when the machine is turned on so you always want to stand to the side for a minute after turning the machine on before beginning work. Never position yourself in line with the wheel.

smontanaro 

Thanks. Your responses prompted me to run out to the garage and take the bench grinder down to my basement lair, where I quickly performed a right-wheelectomy. (Blood loss was minimal. Only needed a small touch with the cauterizing iron. ) It was five-inch with 1/2-inch arbor. I've now located a (hopefully suitable) buffing wheel. Just to confirm - 3600 RPM isn't going to be too fast for polishing? If so, I imagine I can find an inline dimmer of some sort to control the speed.

I'm filling up my Amazon shopping cart. I was already there to get a new laptop battery and a Raspberry Pi. I figured I might as well get everything I need in one stop. Do people have favorite polishing compounds for this type of work? I'll primarily be polishing aluminium bike bits.

gugie 

I guess I need to do a more thorough job with my Atelier tours...;-)

I've got two grinders - one with two stone wheels of different roughness, the other has a scotchbrite wheel on one side, polishing cloth for the other, both spinning at 3600rpm. I get my polishing compound at Harbor Freight, but if you've got a cart going on Amazon, this will work.

The scotchbrite wheel is great for pre-polish, but you have to be careful on aluminum, it'll cut through it quicky if you're not careful. Polishing wheel with rouge gets things nice and shiny.

xiaoman1 

Yes, but I would be careful to either keep the buffing pad very clean or put it away before grinding any metal...small metal particles on a buffing pad can really cause one a bad day when polishing that fine 3ttt, Cinelli stem or an unobtanium vintage piece.
Best, Ben

merziac

smontanaro

I'll just add that the motors are typically the same. Dedicated buffers will have longer arbors to space the wheel out from the motor for better access and lessen the damage if it catches the workpiece and throws it into the bench and doesn't necessarily get tangled up in the motor.

This is where it should have a clean wood surface to minimize the damage.

This is where finesse comes in, go slow and be patient, it is an art to be sure.

RobbieTunes

Repertoire?
Really?

dddd

Running an AC electric motor on a dimmer switch is usually a big no-no as it will heat up the windings and burn out the motor.

An AC motor usually has to be designed to higher-cost levels to work with whatever electric speed control might be used, and a "dimmable" AC motor doesn't come with a bench grinder.

Note that a typical fan 3-speed switch is not wired anything like a dimmer switch. A variable-speed drill or Dremel motor on the other hand has a special wiring design for this.

smontanaro 

I love me the occasional 25¢ word.

JohnDThompson 

That's what I do with mine. One side holds the grinding wheel, the other either a buffing disc or a wire wheel, as needed.

smontanaro 

So I can use something like a 3sp fan switch? Or is that a wiring difference as well? Something I can put online to safely control motor speed? I know just enough about electricity to keep from shocking myself while changing a light bulb. Usually.

JohnDThompson 

Wear face and eye protection, and try not to stand directly in front of the buffing wheel, if possible.

merziac

This too.

And while I wholeheartedly agree, I like you have spent my whole life wrangling and handling tools of all types in all types of environments, many far from less than hazardous, as it usually is.

I always hope that the safety side of the situation is a given being a rudimentary part of the process once it's assessed, step into a shop, turn on or pick up a tool and you should already have your wits about you as well as your common sense.

If you are unfamiliar with a tool and or a process, your common sense should already be elevated, this is how you learn the right thing without learning it the wrong way.

Kabuki12

If you want to get good results with your aluminum get some jewelers rouge and treat the wheel with it (while it is spinning!) . You will be amazed at the mirror like finish. Be careful around logos or printing as the buffing wheels tend to remove a bit of material.

madpogue 

Depends on the provenance.

smontanaro 

Thanks for the safety advice. Will take it to heart.

Aside: I still have my dad's old Craftsman table saw (cast iron table and extensions). It's probably 70 years old or so. It never had a blade guard that I ever recall. In fact, I never knew it had one. Years later, I stumbled upon a users guide for the saw. Lo and behold! There was a blade guard in the parts list. I imagine my dad tossed it out before first use. Since that was the only saw I ever used, I thought blade guards were a more recent invention.

jiangshi

This is a great source:

https://www.caswellplating.com/buffing-polishing.html/


Edit: Good starter kit:
https://www.caswellplating.com/3-4-h...ing-kit-8.html

merziac

Well Mr. Thompson reiterated the safety side that prompted my take on it.

Yep, me and mine too, the good old days when men were men and safety equipment was an impairment to getting the job done. Many of them had highly dangerous jobs that made running a table saw child's play for them. He was an expert with most any and all tools and machinery, fortunately he imparted some of that to me through my Dad and directly from hanging out with him when I was little. He had no sense of humor about it and instilled that very early on and it has served me well.

Mad Honk 

My buffing grinder only works well with Jazz in the background. Smiles, MH

RobbieTunes

All this French....

BFisher

You can even hang your grinder/buffer on a French cleat:
https://www.stochasticgeometry.ie/2017/09/09/french-cleats-and-bench-grinders/



I have a brass wire wheel on the bench grinder in this photo:


Super handy!

gugie 

Just like table saw safety.

Also note that you should wear an air filter, at least one of those inexpensive disposables. When I think I'm just going to do a quick polish, I end up with black boogers - some of that gets to your lungs.