Full transcript
0:00Angle grinders are arguably the most
0:01versatile and useful tool in metal work.
0:03However, they can also be the most
0:05dangerous. In this video, we're going to
0:07go over angle grinders, the different
0:09wheels or discs you might use on them,
0:11some of my favorite applications, and
0:12also how to use it well and be safe
0:14while you're at it. These are the five
0:16angle grinders that I have. They're all
0:184 and 1/2 in grinders. There's also
0:20larger sizes available if you're doing
0:22really heavy stuff. Um, but there are
0:24some differences between them. These
0:26three right here are corded and these
0:28two are cordless. I still prefer corded
0:31grinders whenever I'm working near an
0:33outlet because they just seem to have a
0:35little bit more power. Now, between
0:37these different grinders, something that
0:39really sets them apart is the type of
0:41switch that they have. So, these old
0:43DeWalts, these are a little bit higher
0:44amperage grinders. These things uh are
0:47pretty powerful and hard to bog down,
0:49and they just have a slide switch right
0:51here that you can turn on, and if you're
0:52doing a lot of heavy grinding, you can
0:54turn that on and just not worry too much
0:56about it. Now, from a strict safety
0:58perspective, this is not as good as a uh
1:01paddle trigger like this right here
1:04where you have to hold it down. So, if
1:05it got away from you for whatever
1:07reason, it would turn off. There are
1:09also some with a handle trigger back
1:12here. That's more common on larger
1:13grinders, but they do make some smaller
1:15ones that have that also. Now, another
1:17difference between these is the amperage
1:19on this Harbor Freight one is quite a
1:21bit lower on the motor, so it's a lot
1:23easier to bog down. Now, if you're
1:24shopping for your first angle grinder, I
1:26would look for something with a paddle
1:28trigger like this 4 and 1/2 in grinder.
1:30Um, and I wouldn't be afraid of
1:31something corded, unless you know you're
1:33going to be doing a lot of work on the
1:35go. Let's just talk a little bit about
1:37installing the different wheels and
1:38discs. Um, each of these three installs
1:41in a different way. So, just about every
1:42angle grinder has a threaded spindle
1:44here with a backing plate and a nut. And
1:48some of the wheels like this will just
1:52thread right onto there. And that can be
1:54pretty convenient. Tighten it down like
1:56that and you're ready to go when it
1:58comes to using these wheels with a
2:00standard diameter right there. Um, then
2:02you install the backing plate right
2:04here. And this has a shoulder on it. But
2:06notice these two are different
2:08thickness. So this is a thinner about an
2:11eighth of an inch thick uh wheel. And so
2:13you drop that on and it sits basically
2:15flush with that shoulder. And so when I
2:17install the nut, I want to put it with
2:19this side down right there to cinch it
2:21in place so it won't sit loose. However,
2:25when I'm installing this thicker
2:28wheel like that,
2:30notice there's still quite a bit of
2:31room. And so I can install this the
2:34other way around like that
2:38with that shoulder
2:40down inside the wheel. Just about all
2:42grinders have a spindle lock on the
2:44back. You just press that button. It
2:45prevents it from rotating. They come
2:47with a spanner wrench you can use to
2:49secure the spindle nut. You don't need
2:50to go crazy on how tight it is, but
2:53honestly, I usually just grab this
2:56together and then crank it tight with
2:58the wheel. Then when I'm done, if I just
3:00grab the wheel, it'll grab that nut and
3:03spin it off. So, I don't usually end up
3:04using the wrench, but uh sometimes you
3:07end up needing to. I just mentioned the
3:08guard here. I know some of the cool kids
3:10brag about removing their guards. I
3:12think they need to do something more
3:13impressive to brag about. But regardless
3:16of that, it's a good safety measure in
3:18case one of these pressed wheels
3:19explodes or um if you have a bunch of
3:22debris or if your hand slides, it's just
3:24uh it's nice to have there. Now, if you
3:26are using a cut off wheel, a fully
3:28contained guard like this is also a good
3:31idea. or on these Milwaukee grinders,
3:34it's pretty nice because they have an
3:35attachment that just slides right over
3:38the existing guard um for those
3:41situations like that. Now, while we're
3:43on the topic of safety, let's just talk
3:45about some of the personal protective
3:46equipment that I'd recommend. Um
3:48definitely want to wear safety glasses.
3:50You can have stuff flying all over the
3:52place and sometimes you'll lose a big
3:53chunk or with a wire wheel. Some of
3:55those will go shooting out like
3:56javelins. Uh they're loud. Definitely
3:59want to protect your ears one way or
4:00another. Noise cancelling headphones.
4:02Don't uh do that unless they're
4:03specially designed to. Um breathing.
4:06This is a respirator. You probably want
4:08a dust mask or a respirator if you're
4:10doing a lot of grinding cuz it sends a
4:12ton of stuff up into the air. Now, full
4:14face protection is a good idea beyond
4:16just regular safety glasses. And you can
4:18wear a face shield, but I usually just
4:20use my welding helmet turned onto the
4:21grind mode for full face protection.
4:23Gloves can also be a good idea, but you
4:25want to make sure and keep them far away
4:27from that spinning wheel where they
4:29could get caught. Let's go over the
4:31common wheels and discs that I use, when
4:32I'd choose them, and how to get the most
4:34out of them. Let's start off by looking
4:36at a standard hard rock grinding wheel.
4:38Now, they have a label on them that
4:40typically shows the max RPM as well as
4:42if they're a face or an edge grinding
4:45wheel. And this can work for both. So, I
4:47have my workpiece clamped in place and I
4:49can get a good grip on the grinder like
4:51this. And I'm going to grind on that
4:53edge, holding it up at an angle. I'm not
4:55trying to use the whole face. I'm trying
4:57to use that edge up at about uh 15 to 30
5:00degrees and then move as consistently as
5:03possible. And you can see just after
5:04that first pass, you can get a pretty
5:07even bevel with it uh if you move
5:09steadily. So, one method if you are
5:12using this to bevel a plate, which is a
5:14good use for a hard rock grinding wheel.
5:16Honestly, this little grinder is is a
5:18bit small to bevel some 1/2in plate, but
5:20um it's a good example here. Now, if I
5:22work my way across evenly like this, I
5:25think that is the method that gives me
5:27the most consistent bevel. However, it
5:30takes a long time. And so, another
5:32approach is to just work in about 1 in
5:35long sections like this and work an inch
5:39at a time down to the size that you're
5:41shooting for. So, uh a few different
5:43approaches there. I'm sure other people
5:45have other ways of doing it, but uh
5:47either way can give you a nice bevel
5:49with a hard rock grinding wheel, and
5:51that's the main place I'd look to use
5:52them. They can really gouge your parts
5:54if you're trying to dress welds. Now,
5:56this is a cut off wheel, and this is one
5:58of the most common that you'll see used.
6:00I have the full guard like I'd showed
6:02earlier on it. And notice the way that
6:04this rotates. I want to position it so
6:07it will pull away from me if it were to
6:09get caught. So, that's uh what I'm doing
6:12here. And then I have a firm grip on the
6:14tool and I just want to allow the tool
6:16to do the work. So I'm not pressing too
6:18hard into the work. Now I want to keep
6:21an eye on the sparks and I'm standing to
6:23the side so they just work their way
6:24past me and uh let it eat until you make
6:28it through. And you can get a pretty
6:29nice cut with those. Now they do make
6:31these steel ones. This is made for metal
6:34even though it looks like a tile wheel.
6:35And I was really excited when I saw
6:37these a few years ago um because they're
6:39supposed to last a lot longer. or they
6:40won't explode like the other ones. Not
6:42that that happens very often. Um, but I
6:44found these to be very slow and they
6:47vibrate a lot. So, I don't like them. I
6:49like the uh traditional style more. Now,
6:52when you're cutting through a piece of
6:53bar like this that's a little bit
6:55longer, this flat bar, there are two
6:57schools of thought. One is to cut
6:59through the short way on the short edge
7:01like this. And this can be really
7:04effective and you can cut pretty fast
7:06like that. Uh, however, it is more
7:09likely to bind if you do have residual
7:11stress or something else that pulls it
7:13together on your wheel. So, another
7:15approach uh is to just work your way
7:18down through the surface and you
7:21basically score it and then continue to
7:24grind your way down through. Now, Jason
7:27with Fireball Tool did a little uh
7:30experiment a little while back where he
7:33tried both methods and uh believe that
7:35the wheels last longer with this. I
7:38think both work pretty well, buth you
7:40just have to be pretty cautious. Now, if
7:43you are going to clean this up, don't
7:45grind like that with a cutff wheel.
7:47They're not made to handle a side load.
7:49So, instead, switch over to a flap disc
7:52to debur. We'll look at flap discs here.
7:55Um, now I use these more than anything
7:58else and I use them to dress and finish
8:01welds. So I range from 40 to 120 grit.
8:06My most commonly used is an 80 grit like
8:09this. And that's usually fine enough for
8:10the functional things that I do. I'm
8:12just going to weld an outside corner
8:14joint here with MIG, which is something
8:16that I do all the time, whether it's on
8:17mitered tubing or uh just the sheet
8:20metal work. And that weld isn't bad. You
8:22could probably leave it for a lot of
8:24functional things, but if you wanted to
8:26dress it up, this is where a flap disc
8:28is really nice because it engages that
8:30whole surface. It's just a little bit
8:32more compliant and it takes a lot less
8:34skill to get that to uh smooth out than
8:37you can with a grind wheel. So, it's
8:39really nice for that. And you can work
8:40your way down through finer grits. So,
8:42if you're finishing welds, flap disc is
8:45my go-to. Now, they're also available
8:48with a curved edge like this for fillet
8:50welds. And I just pulled this out of the
8:52scrap bin, a little uh coupon from a
8:55previous video, stick weld. And if you
8:57work your way down in with these curved
9:00wheels, they can uh come out really nice
9:03and smooth. It's kind of a hassle to do,
9:05and it's difficult to do without
9:07thinning the material a little bit next
9:09to your weld. So, I wouldn't do this on
9:11all of them, but if you have a special
9:13need for a look like this, or if you lay
9:15down a stinker, it can be pretty nice.
9:17Now, this right here is a um strip disc
9:21they call them. They're just off of
9:22Amazon and they're pretty cheap and it's
9:24one of my favorite things I found for
9:26weld prep. So, it can remove mill scale
9:28and rust and those sorts of things
9:30really fast without eating into your
9:32steel. So, I really like it for that.
9:35So, um these are definitely something
9:37that's worth keeping on hand. You can
9:39see that was just in real time how quick
9:40you can prep that surface. One last
9:43wheel we'll look at that's especially
9:44useful if you run uh flux processes like
9:48stick welding or flux core is a wire
9:50wheel. Um this can just be really useful
9:53to finish removing the slag from your
9:55weld. Uh prep it for another pass. Hey,
9:58thank you so much for tuning in today.
10:00If you enjoyed this or learned
10:01something, let me know by hitting that
10:03thumbs up below. And if you are just
10:05getting started with welding, I've put
10:06together some affordable online courses
10:09linked in the description below that'll
10:11walk through step by step and help you
10:13to learn so much faster than you can
10:15learn on your own because it really puts
10:17some structure to your practice. So, be
10:19sure to check those out and we'll see
10:20you next