Welding Mild Steel Sheet Metal | TIG Time

hey welcome to welcome home of TIG time hi I'm mr. TIG and today we have a request coming from one of our viewers arc streams and arc streams has asked us to take a look at what's the best technique a welding mile steel sheet metal now he was requesting 16 gauge and we're here at the track at the Indianapolis Motor Speedway and we were able to round up about 18 gauge materials so I think we can show you a little bit about this anyway what I've got here is just it's mild steel it's very low carbon steel and you can tell that it's got a lot of rust on it so all we did was we prepped it by going over to our power wire brush wire brushing off the rust and I'm placing it in this fixture right here and this fixture is only for holding purposes typically we use this for welding titanium and Inka nails and things like that but there's no argon gas flowing from the backside nor is there any needed so I want to talk about the the setup for this you know ideally in a lot of welding processes you want to put a gap in your part and the gap is designed for penetration typically and sometimes you get gap and you don't want it but in this particular case we don't want gap it's not our friend so we're going to make this part fit up as tight as possible we're going to tack weld it and again this this purge block does not have purging in it it's just for holding purposes now the procedure is this we're going to use a 2% thoriated tungsten which we have ground to a point and it's a 1/16 diameter and it's 2% thoriated the have no fear we're not losing 2% thoriated tungsten it's not going to disappear off the face of the planet so you can use that you can use serrated there's a lot of alternative Tungsten's I prefer this one it hole the point much better and in aiding myths the arc initiation a lot better so my personal preference we're going to be using argon gas I've got a gas lens right here gas is going to be flowing at fifteen to twenty cfh now on the machine I've got a high frequency start the arc initiation is going to start at about five amps that's what I've requested the machine to do now I'm using a precision TIG 375 and you can actually ask it to start off at two amps I don't need that for for eighteen gauge material so I've got high frequency start it's only going to initiate the arc and then it'll it'll disappear DC electrode negative or DC minus now when we talk about free flow and post flow here's what I like to do on the machine there's a built-in half a second free flow and what that's designed for is actually just to clean out the system clean out the cables and by the time you start welding you've got gas coverage now the post flow to me is more important because what I do is I use the post flow also for the pre flow and you say well why would you do that well you get a surge of gas if you get on your welding machine you hit the foot control you get this quick surge what I like to do is I liked it hit the post flow let it run for about five seconds and before that post flow goes off I go ahead and hit the foot pedal again start my arc initiation and it's very low amps so again fifteen to twenty cfh there is no argon coming up from the backside and finally the filler material that I'm going to use this filler material is er 70s - and it's just a mild steel filler material I like using 0.045 a diameter and it just feeds a lot better it wets a lot better and I don't have to add a huge amount of amperage to get this to melt so that's pretty important to you technique of the puddle that you're welding so oh four or five and I'm just going to be dabbing dabbing dabbing and I'm going to tack this part in a couple places because it's going to have a tendency to try to move and it's going to try to overlap and once it overlaps in this direction well you're going to have nothing but Distortion so you can put as many tax as you want so let me get my gear on I'm going to attack it weld it and I'll show you the results okay what are my amps okay go ahead and keep calling them out every ten seconds okay steel you know typically doesn't world quite as clean as some of the other materials just you know there's a lot of phosphorus in it and you can see it actually kind of float to the top blue got a little win okay I had to stop abruptly just because there's a little bit of breeze coming through the doorway here so I zoomed the world I hesitate just a little bit and I'm still getting a little bit of breeze so I'm probably going to have to shut the door anyway it said that it's welding a pretty plain at the end of the world add a little bit of extra filler back off on the foot control let it re solidify and there we are okay we're running pretty slow travel speed it probably notes a little bit of bubbling in the puddle and that's just the metal itself you're going to get that until you add filler your filler kind of stabilizes it it's just constant damming technique damn they have and you know I'm not using a lot of amperage I'm probably somewhere between 13 ounce or so and the beauty behind TIG welding is you can get out of position and you can stop and restart your arc is make sure you overlap your start and stop okay so I'm going to do that right now I'm going to actually taper off add a little extra fill or I do it on every all the way and I back off and resolidify the puddle and that's it nokey i'm repositioning start the earth again exactly where finished off and what I do is I let the puddle get the full diameter and I'm back up just about a sixteenth of an inch and they start all over again there's there's no real hurry in this it's it's more artistic you know you're trying to run your tick torch and your foot control add filler at the same time I'm gonna get near the end of the plate so I'm going to go ahead and add little extra filler back off I'm down to ten seven about five amps and I hold the post flow in position for about five seconds here and that's it okay now that I finish welding I you know I welded maybe six inches and I stopped just about one inch shy I tell you what's really critical you probably heard me talking about stopping the arc adding filler when you restart make sure you start on the same exact place and then get things boiling and get it to liquid and then back up maybe a sixteenth of an inch and once you do that then you'll tie in to your existing wheel then you can take off running again do that as many times as you need to so what I'm going to do right now is I'm going to go ahead and take the plates out do a little a little visual inspection you know the first thing that I look for in a visual inspection as I as I actually look at the top side first and I look and see if the the filler material is above the parent material and if it is I'm in good shape that drops below then I could very easily have a weakness but a lot of times when you're doing sheetmetal work and things like that things are in a radius shape and they holder their shape real well so take a look at this I don't have any underfill anywhere I don't see any cracks or transverse cracks or anything here so topside looks pretty good now let me turn it over and let's take a look at the backside and I do the same thing here I don't need a lot of penetration but I do need to make sure that it wets to both sides because a lot of times it will try to try to go to one side and chill now I did this with about 30 or 35 amps and the only way that I can succeed getting that small of a bead is my arc has to be very very close very very tight and that correlates into voltage so I'm probably running about nine volts now you as an operator can't see the voltage on your machine but you certainly can see how close you get the tungsten to the puddle and of course the hazard of that is that if you get it too close you're going to contaminate your tungsten and you have to re grind so take a look at this I just dabbed at a very consistent rate you know your dabs maybe 10 dabs an inch and minor 13 there's nothing wrong with either of them to just make it consistent so this one right here this this passes the visual inspection and that pretty well wraps it up with the steel carbon steel again er 70s to 0.045 diameter thanks for watching take time I'm mr. Teague

Channel: Weld.com

Views: 309,420

Rating: 4.7533255 out of 5

Keywords: welding mild steel, Welding, TIG Welding, Weld, How to Weld, Welding Tips, Weld.com, TIG Time, Tungsten Inert Gas Welding, Heliarc, GTAW, Mr. TIG, mister TIG

Id: zrPIbYnvDdo

Length: 12min 23sec (743 seconds)

Published: Fri May 24 2013