Bench grinder motor load for buffing and wire wheel

[phansen39]

My main grinder is delta 8". But my little old craftman 5" died last night. It was actually my 1st power tool I purchased 1985. I was 14. So in the market for a new grinder for buffing and wire wheel. I'm thinking getting 2 one for wire wheel and another for buffing duties. I have little hf 5" grinder for last year still in box. So the question, applying the same amount of force to grinding, wire and buffing wheels what loads the motor more to less?

 

[kc-steve]

As a rule of thumb, the larger the wheel, the larger the horsepower required whether a grinding, buffing wheel or wire brush. Buffing has some other factors such as how much force of resistance is applied to the wheel. It isn't recommended by many manfacturers of buffing compounds to apply a lot of pressure but it is still beneficial to have a motor with high horsepower, for instance a minimum of 1/2 HP, but 3/4 HP is better.

And many Chinese grinders are made with aluminum windings and can heat up. Not good for longevity.

Steve

 

[2oolhound]

If you go to "Show your grinders" thread you will see how serious you can go on grinding and buffing tools. Most serious buffing companies use 10" wheels and might stack em up to 4" thick. Buffing is all about speed at the surface of the work but you eliminate a lot of pre-sanding if you have a good buffer. The metal actually gets moved around a bit at some stages of the process. There is a ton of info on buffing if you google it.

I use a 3/4 HP 3400 rpm grinder with 8" buffing wheels but now have a 1HP 3450 rpm grinder to try with 10" wheels eventually. It does the job for my own stuff but it takes time. I keep a 6" twisted wheel on my 6" 1/2 hp grinder and it's handy as heck for cleaning rust and gunk off parts.

My 6" has the twist wire wheel and a fine stone for sharpening hand tools.
The 8" is used for buffing
The 10" is for grinding lots of metal fast and has a fine and coarse stone. (the next buffing wheels I get will be 10")