Could be an angle grinder in my future

Perhaps a little off topic for the board ... but then again, firewood shelter construction would be one of the beneficiaries ...

I've never owned an angle grinder but I have a lot of steel pipe and corrugated iron, which is cumbersome to handle with a hacksaw and aviation snips.

Just wondering what you use yours for. I know I can cut steel and smooth jagged surfaces, but what else?

I should admit here that I'm a serial power tool buyer. When I'm in the hardware store they call to me with their honeyed voices, "Take me ... use me ... I need you ... you need me", but then I get them home and they sit on a shelf in the shed pouting and sulking.

What do the various disk diameters mean? Is bigger better? Any brands to avoid? Are battery ones actually usable these days or a waste of time? Any other advice/observations?

 

A 4" ish angle grinder is. One of the most useful tools you could own.
Get a 10 pack of cutoff wheels. And a few grinding wheels . And a cup and a straight wire wheels. A buffing wheel is handy if you have a job for it.
The cordless DeWalt 20 volt tools are a Very good tool and Very useful. But if you have a lot of work to do a corded is better. I have a Mikita and some off brand . The Makita is a barrel grip and the off brand has a grip and trigger. The Makita is by far the better tool but the off brand has accomplished A lot of work.
No shop is complete without an angle grinder.
The 7" and 9" are heavy duty tools that will remove A lot of steel in a hurry.
All of them Must be respected. !!
They will git ya if you get complacent .

 

I use them for what Cold Trigger Finger said. I flap disks better than grinding stones. They grind faster and do a better job. For your first grinder, get one that is variable speed. I think I have five 4'' gridners, each with something different on them.

 

But a 4.5" grinder, any name brand will do, dewalt, Milwaukee, Bosch, etc. No harbor freight or tool shop garbage. Get decent cut off wheels, wire wheels, and a few hard wheels. For beveling, taking off material in a hurry and stripping paint and rust, use the soft pads, you'll need a backer and a nut that will last you a long time, and you'll need good pads. Cubitron 36+ grit are the best I've used yet, and believe you me, I've used thousands. I don't even bother with hard wheels anymore. My DeWalt 13 amp I use at work it well over 8 months old, and I use it every day, in a professional setting, using it hard quite often. The cubitrons not only work better in most applications, but they are also WAY WAY WAY easier on the grinder itself and your hands. A lot less vibration.
Also, for crying out loud, while using a cut of or hard wheel, do not push the Sparks away from you, your asking for a kickback. With the grinder peg facing away from you, use the right side for cutting, wire Wheeling, hard Wheeling, etc. Invest in a face shield with replaceable lenses, and where safety glasses and gloves minimal at the very least. I use a grinder every day at home and at work, every day. I cringe every time I see someone on national tv pushing Sparks away with the cut of wheel.

 

3M™ Cubitron™ II Fibre Disc 982C | 3M United States
They are expensive, but worth it. If you don't use them much, keep them dry, and or under pressure to keep from curling. What I do is put a bunch on a bolt with a couple washers, turn a couple the opposite way and put a nut on and tighten it.

 

In addition to what was said above, I also use a diamond masonry wheel. Cuts stone and concrete with ease.

 

Get one that you run the trigger with your finger or fingers as part of your grip, rather than one with the little thumb trigger that slides forward. The catch on the thumb style wears out so you will have to hold it continually with your thumb. This is a problem if using it for an extended period of time or for out of position jobs.

 

I also highly recommend a 4" grinder. I have a Milwaukee but any name brand will do. These things run at high speeds and if it would fail - it can and will cause serious injury. Same with blades/wheels/disks - I've personally had a few harbor freight grinding wheels desinegrat at full RPM. Scary. Buy quality - especially when buying high speed tools.

Uses for a 4" grinder that I can think of:

cutting pipe/angle iron, strut, plate steel

Sharpening lawn mower blades - use a flapper wheel as the grinding wheel will "overheat" the metal and you will loose your edge quickly

Cutting concrete, FIRE BRICK (just used mine to get my fisher religned), tuck pointing

Must have when welding

And tons and tons more. Buy one.

 

Buy one! I'll bet after 3 or 4 years you'll have at least 4 of them, all with different wheels & wire brushes on them.
For some reason I got started with Makita, I'm up to 7 of them now. I've never had to throw one of these Makita's away but along the way I've had a Dewalt and possibly a Milwaukee and both of them didn't make it but this was over the past ? 25 years. I do periodically grease the gears on them, like every 5 years or so.

 

I agree with getting a "trigger" switch instead of an on/off switch (slide) only because when things happen they happen fast and you can immediately let off/turn off the machine.

Another GREAT piece of advice. High RPM's and disintegration are not two things you want happening. I require my students to always wear safety glasses in the shop, but whenever using grinders also a clear face shield is required. When buying discs or wire wheels know your grinder's rpm's. Look at the item you are purchasing and see if it is built to operate in that rpm range. I used to think "if it fits it is for it". Not true. Otherwise, a very handy tool and you will wonder how you did without it.

 

I had a el cheapo ($14.95) HF 4.5" for ten years did a lot of cutting and grinding with it the switch finally gave out.

 

Thanks for all the advice. I will digest and come back with any further questions.

Don't think me rude if my responses are delayed. It's a matter of zones. Some of you are in the Pacific zone, some Central, some Eastern, whereas I ... I am in a land of both shadow and substance, of things and ideas. I've just crossed over into The Twilight Zone.

 

Flap disks are the best. Genius invention. I've got two running, one with wire brush, one for flaps, cut-offs etc. all the rigid disk stuff like that I can change by hand in a flash where the wire wheels are more of a pita.

 

I have a 4" DeWalt. I'm not a tool guy, but I use that grinder for sharpening mower blades. I mow alot of grass and it was worth the cost just for that use.

 

You can use them to cut off the bent bits and some off the other end to re-balance the blade after you've mowed over one pile of rocks too many as well.

 

Most used power tool in the shop. Hold on tight, it'll inflict mayhem on you if you aren't careful.

 

I have a Makita battery grinder and I love it for the smaller job or when climbing.
I have 2 Metabo corded grinders and I guarantee they will outlast any other brand. We use our grinders hard!

As for the switch, it's preference.
I won't buy the paddle style, ever!
And I want the thumb/slide/locking switch on the back of the body, not on the side.

Look for the cutting wheels called Slicers. They work good and cut really fast because they're thin.
We use a lot of the 40 and 60 grit Flap Discs. They take off paint faster than anything else.
A twisted wire cup brush removes rust the best.
If removing a lot of metal, the old grinding disc is still the best.

 

i use one with a narrow diamond bedded wheel to cut plaster for my remodeling business. makes an epic mess but is accurate and effective.