Mag, Mig and Arc Welding How To Tips and Information

Hi I'm Mike Edwards from Home improvement Doctor, part of DIY Doctor As you know we are builders and every now and again we need steels welded together Lintels made for door openings etc and when we need something like that we come to the experts We come to see Ivor at Special Welding Services and he puts it together for us We thought this was a great opportunity to teach you a bit about welding. Today we are going to show you Arc Welding To weld 2 surfaces together a strong electrical current passes through the electrodes and melts the metal around the joint using a metal component in the welding gun itself to complete the electrical circuit The metal fuses together to form a joint as strong as the actual materal, if not stronger the first thing that Ivor is going to show us is A MAG welder so that's metal active gas M A G and you can see the central core of metal there. The welding gun itself passes out a gas and as the current is passed between the surfaces it fuses these bits of metal together The gas keeps all the oxygen away It's the oxygen that contaminates the weld and causes problems in the weld bubbles and impurities make it a weaker weld in all instances of arc welding, whether we are going to be using the MAG or some stick welding - we will demonstrate later - everything is designed to keep as much oxygen out of the way as possible That's a brief explanation of MAG welding I'm gonna give this to Ivor He's going to weld this together and show a joint using a MAG welder over to you. Ivor says: [you might need to filter the lens - it might be too bright] Helmet and safety gloves on! That is tacked up Ready for the weld That joint is now done There's one successful mag joint I've got a couple of questions for Ivor so we can understand - that looks dead neat mate! Mike: You said you were going to 'tack' it before you weld it - what did you mean? Ivor: That holds the joint together so it doesn't move Mike just a couple of spots to keep it together? What were you bashing off with the Bolster afterwards? Ivor: Just a bit of slag at the top of the weld puddle, which can contaminate the weld and allow oxygen in So oxygen is the thing that makes a bad weld And whats the next type of welding We are going to do on one of the other joints? Manual metal arc - a basic coated electrode The gas protects the weld in MAG welding, here you have a metal core with a flux coating to protect the outside form the oxygen getting in. The gas protects the MAG weld the flux protects the Manual Metal weld - from oxygen getting in You have different thicknesses. Thicker for heavier metal. What's the thinnest metal you can weld? MAG welding .6 of a millimeter, Manual metal arc about 1 or 2 millimeters. Definitely DIY stuff Yes we realise that lots of our users go out and buy small welding equipment for their DIY projects It's great for them to see what the professionals do The important thing is I mean I have heard of 'Arc Eye' I am assuming that is why you are wearing a welding mask? what is that? The welding helmet has sensors inside to instantly darken the lens as soon as the welding process starts. However even someone walking by can catch a flash and the light is so intense it can burn the retina of the eye causing blindness. Arc Eye is like intense sunburn on your eye It is really painful So be safe and get the right equipment It is so important We will let you get on with Stick welding I'll get out of the way Take the slag off the joint Another perfect joint by Ivor that joint is made by stick welding or manual metal arc the flux around the stick keeps the oxygen away. Oxygen is our enemy when we are welding Ivor where does the current come from in this process? In the MAG or MIG welding the power comes up through the bench and burns the wire as it makes contact With manual metal arc welding the current can either come up through the bench or through the work itself. You can have DC negative power. So you complete the circuit one way or the other? AC current is more the DIY market - it can be plugged into the mains DC welding makes it easier to get a smooth joint as there is more power coming through the equipment AC welding will give off more sparks - you get a break in the arc so that's why people try DIY welding and say "this isn't for me"? That's right because it is much more difficult than using the professional equipment So there you go DIYers and Home Improvers If you want to do welding go and spend 5 or 6 grand on the kit! Instead of 200 pounds for the DIY equipment You only get what you pay for That's fantastic We now have a lovely T section that's going to go into a building and hold up some bi-fold doors for us The answer there is we genuinely believe, if you want a job like this done You should come down to the professionals We are grateful to Ivor and Special Welding Services for showing us how this weld works. We will continue to use them Hopefully you have someone local who can do this job for you Mike Edwards - Home Improvement Doctor - and that's Arc Welding!