What Is the Best Grinder ?

[delmarrey]

Originally Posted by bangkaboat

I can only comment on the basis of my own experience & education. A few years ago, the nice people from Walker spent a day educating us(Vancouver Drydock) on all of the equipment they were supplying, after one of our labourers hurt himself. As we steelworkers were using their 5" grinders, exclusively, we were surprised that they spent so much time on the issue of mixing disks in the afore-suggested manner. Still, as we were paid to be there, no one complained. Now, after about 35 years of using grinders, formally & informally, I now have a piece of paper that says that I know how to use one.

However, when I was 19 & a steel fab. apprentice, I used the remnants of a 9" disk in a 7" grinder & ended up with 162 stitches in my left thigh, when the disk exploded. I had a lot of time to think about it while riding to the hospital with a first aid attendant's thumb holding my artery against my femur. So, once again, I suggest that this is an ill-advised practice.

Mike

Yes! And I've seen a guy get all wound up in a lathe because of one single thread hanging from his apron.

The operation of powered tools is an assumption of risk we all take any time we hold a tool. I too had a nice gouge taken out just above my knee (10 stitches) from a 9" grinder. But in my case it bounced off a unseen weld and hit me right in the leg. Instant meat grinder. I now use a death grip on the big ones.

If one doesn't feel comfortable down sizing discs, then they shouldn't do it!!!!
But on FG I doubt that would even be necessary.

[boatsmith]

Disks for steel are different than disks for aluminum. A steel grinding disk used on aluminum will load up and the aluminum will get hot, expand and the wheel will likely come apart. For fiberglass I have always used phenolic sanding discs, not wheels. If they are loading up then they are too fine for the task. I blow my tools out regularly. I don't think blocking the airflow with filters will do anything but generate more heat which is what kills tools the fastest. I have Milwaukee 9" 7" 4 1/2" Makita 4 1/2" 5" Dewalt 4 1/2" 7" I also have Milwaukee and Makita 7" variable speed sander/polishers that we use a lot. We also have a full complement of air sander/grinders from 2" to 9". I have used worn 9" and 7 " in smaller grinders for 30 years and have never had a problem or heard of this happening in the yard. Wheels that come apart have usually been damaged or are being improperly used. just my thoughts