1 00:00:11,210 --> 00:00:15,889 Hi everybody, welcome to another video from Grimsby Institue, I am Joe Brodell 2 00:00:15,989 --> 00:00:20,069 and this video, we're going to run through a very, very basic introduction of MMA 3 00:00:20,170 --> 00:00:25,829 welding. MMA Welding is, manual metal arc and it can also be known in the trade as 4 00:00:25,930 --> 00:00:33,630 stick welding. Or it can also be known as SMAW, which is shielded metal arc welding. 5 00:00:33,729 --> 00:00:38,170 It was first developed in eighteen eighty eight in Russia with an electrode that had 6 00:00:38,270 --> 00:00:43,270 no flux coating and early nineteen hundreds they started to use the flux 7 00:00:43,369 --> 00:00:50,510 coating. And this is what we've got now. So this is a 3.2mm electrode. 8 00:00:50,610 --> 00:00:59,389 Other standard sizes, 4mm and also 2.5mm. On the electrodes themself, they have 9 00:01:00,139 --> 00:01:07,720 some markings on the end. So this one says E6013. So E means electrode. The 60 10 00:01:07,819 --> 00:01:12,910 is the tensile strength of the rod. The 1 is what position it can be used in. 11 00:01:13,010 --> 00:01:17,809 And this 6013 rod from Oerlikon is a well rounded multipurpose position, Rod. 12 00:01:18,230 --> 00:01:24,130 And the three at the end is AC or DC. On the packet of rods themselves. Again, 13 00:01:24,230 --> 00:01:27,769 I've got two packets in front of me. We've got some two point five millimeter rods 14 00:01:28,309 --> 00:01:31,160 and these ones on the on the packet it would tell you what the can be used. 15 00:01:31,430 --> 00:01:38,889 So these can be used between 60 and 90 amps in a range of positions. On a three 16 00:01:38,989 --> 00:01:44,739 point two rods, again, from Oerlikon, these should be run between 110 and 135 17 00:01:44,839 --> 00:01:49,610 amps and again, nice multipurpose rods can be used in a multitude of positions. 18 00:01:51,709 --> 00:01:59,180 Basic tools and equipment for MMA welding, we've got a chipping hammer. We've got 19 00:01:59,279 --> 00:02:11,349 a wire brush. A magnet for helping to set things up at 90 degrees or forty five 20 00:02:11,449 --> 00:02:23,619 degrees. And a set of tongs to save our PPE. Talking about PPE there's a multitude 21 00:02:23,720 --> 00:02:27,860 and all different types of PPE that you can wear. So we'll start with. 22 00:02:29,970 --> 00:02:36,970 Welding gauntlets, sort of a basic standard pair. And then we get 23 00:02:37,070 --> 00:02:44,959 some slightly fancier ones from wild line Lincoln Electric. On your hand as well, 24 00:02:45,059 --> 00:02:50,239 you could also wear a heat shield, this deflects the heat away. To protect your 25 00:02:50,339 --> 00:02:56,779 head, you have welding kromers, again, these come in different styles. 26 00:02:59,270 --> 00:03:02,329 And some different welding hoods as well, so these ones are the basic one 27 00:03:02,429 --> 00:03:09,369 in my right hand and the orange one is a nice Firefox one. To protect your arms, 28 00:03:09,470 --> 00:03:16,259 if you start doing positional wellding, then you can get leatherjackets. Or, 29 00:03:16,360 --> 00:03:25,119 welding sleeves. All just giving you an extra layer of protection on your arms. 30 00:03:25,220 --> 00:03:33,729 welding screen-wise, again, these are react like welding screens, all different 31 00:03:33,830 --> 00:03:37,839 patterns and pictures on the side of them. This is a really nice one from one 32 00:03:37,940 --> 00:03:44,169 of the new ones from Lincoln Electric. And then we get the more expensive with 33 00:03:44,270 --> 00:03:48,860 the airflow on them as well, to protect you from any hazardous fumes, 34 00:03:49,130 --> 00:03:58,769 because when the flux coating burns, it gives off a CO2 shielding gas. The plant 35 00:03:58,869 --> 00:04:06,360 itself, this is a really basic, it does MMA and it also does scratch TIG so basic 36 00:04:06,460 --> 00:04:14,069 setup of the machine, the electrode holder itself, here. Well, we always start with 37 00:04:14,169 --> 00:04:20,669 it going in the positive. And the return lead or the earth lead, as is it sometimes 38 00:04:20,769 --> 00:04:27,329 known in the trade, also goes into the negative. Switch on the back will switch 39 00:04:27,429 --> 00:04:33,329 the machine on and as long as we are set on MMA, on the lever, it's nice and simple 40 00:04:33,429 --> 00:04:38,910 to change our amps, just here. The electrode goes into the electrode holder. 41 00:04:39,010 --> 00:04:53,239 Just slide it in. Grab hold of it and tighten it up. Next thing I'll do is I'll 42 00:04:53,339 --> 00:05:00,759 show you how to strike an arc with a machine. On the bench behind me. OK, 43 00:05:00,859 --> 00:05:04,910 so I've got my PPE on, my air fed welding is screen and my gauntlets, 44 00:05:05,299 --> 00:05:09,880 flame retardant overalls, steel toe capped boots, and I've also got my extraction 45 00:05:09,980 --> 00:05:13,190 hoods as close as I can next move, because it's not as close as what I normally like. 46 00:05:13,399 --> 00:05:55,019 That's why I've got my air fed welding screen on as well. Hopefully you saw 47 00:05:55,170 --> 00:05:59,119 on the video there how just a scratch it and lift it slightly, what I'm looking 48 00:05:59,220 --> 00:06:03,329 for is a nice close arc and I'll talk through some of the defects in a minute. 49 00:06:03,690 --> 00:06:06,779 But what you'll notice as well with the welding rod, it starts to burn away 50 00:06:07,290 --> 00:06:11,190 and you'll end up with a stub when you finish. This can just be discarded. 51 00:06:12,059 --> 00:06:16,089 The fumes that were coming off are from the flux burning. And what it does, 52 00:06:16,190 --> 00:06:20,309 it leaves a protective layer over the top of the weld, which is called slag. 53 00:06:21,019 --> 00:06:24,889 So some of the basic tools we talked about earlier, chipping hammer, this is used now 54 00:06:24,989 --> 00:06:46,279 just to chip some of the slag away. So nice and carefully when you are chipping 55 00:06:46,380 --> 00:06:50,869 the slag away and a little bit of a wire brush just to finish it off. I'll now head 56 00:06:50,970 --> 00:06:58,100 over and we'll talk through some of the welding defects. Few welding defects with 57 00:06:58,200 --> 00:07:07,239 MMA that, you can get this weld has got some excess spatter. And also some under 58 00:07:07,339 --> 00:07:13,910 fill, so excess spatter can be caused by going too slow or having the settings 59 00:07:14,010 --> 00:07:17,959 and amperage at the wrong setting, too high setting. Also actually can be caused 60 00:07:18,059 --> 00:07:26,320 by a long arc length. This one here is very similar again. A bit of underfill. 61 00:07:26,420 --> 00:07:33,070 So either we could use a bigger welding rod, I was using a 3.2 or we could use 62 00:07:33,170 --> 00:07:37,660 a four millimeter to help fill that fill that gap in. This one here is one 63 00:07:37,760 --> 00:07:41,739 of the main defects that you can get with MMA welding, and it's called a slag trap. 64 00:07:41,839 --> 00:07:47,820 So the slag gets caught in the molten pool. What we ideally are looking 65 00:07:47,920 --> 00:07:54,290 for is something like this one where the slag started to peel away on its own. 66 00:07:58,160 --> 00:08:05,000 And that is very basic introduction into the MMA machine and what we look for, 67 00:08:05,000 --> 00:08:07,839 for a good weld. Thank you for listening.