BackStep Technique for Tig Welding Thin Metal

hey Jody here in this week's video we're going to be doing a butt joint a 1g square groove weld 43-thousand stick that's just a little bit over one millimeter and I'm going to be showing a technique called back stepping so let's do it carbon steel doesn't necessarily require a back purged of argon although it wills a lot better with the back purged next best thing is to well that with backing I'm clamping it down here to a big thick piece of aluminum plate however the first plates that I run here I'm gonna use some spacer plates to get it up off that big heatsink it'll still provide some amount of chill and heatsink just not as much as if I clamped it directly down to the aluminum backing I'll do also do a plate where I clamp it directly to the aluminum backing when I get tax on the end of sheet metal like this I add a few extra dabs of filler metal little button tacks that gives me a little bit of extra time when I'm welding to or from to keep from blowing the end away so you see I'm putting two or three little dabs here more than just the absolute minimum once I get the tacks done I'm gonna start around the middle and weld to the end fifty five amps full pedal I'm going to start in the middle well to the end and then I'll start on the other end and weld to the start of the previous bead 43,000 s thick fifty-five amps and number eight Furyk Pro cup twenty CFH there is a rule of thumb in TIG welding that it takes one amp per one thousandths of inch or 40 amps per one millimeter to get full penetration and that holds true up to about a hundred thousandths thick and honestly you're not gonna be doing full penetration weld zhan TIG weld on sheet metal much much more than a hundred thousands without putting some kind of bevel on it now that rule of thumb one amp per 1000 says for carbon steel you need less with stainless more with aluminum and if you use chill bars with any of it you're gonna need more amperage than you would without chill bars let's start here I'm gonna initiate the arc around the middle of the plate I should get my puddle going in less than three seconds that's a good rule of thumb as well if it takes you more than three seconds to get your puddle get moving you probably need a little bit more amperage three-second rule don't you love those little rules when I come to that button tack that gives me a little time to start tapering off the foot pedal you notice I leave the rod in there just a little bit here and there that prevents from blowing away a hand on something really thin once that's done I immediately go back to the other end and I'm gonna start on that other little button tack and then weld to the previous bead now this little button tack I have on this end with an extra couple of dabs of metal also helps me light up on and prevents me from curling it under blowing it away that really helps on thin metal and as I tie in here I'm gonna overlap a little bit add less and less filler as I keep moving and taper off slowly this is cold rolled steel you can't hardly make it crack if you no matter what you do however if it was chromoly or some kind of hardened stainless steel it would crack in the crater so tapering off slowly is a good idea all right full penetration they're not as good as with argon shielding but a lot better than without backing and it for a really thin metal like say in the Oh 20 range back stepping like this and several little really short runs about an inch long can really limit distortion by locking things in place it's just a technique that's useful for thin metal now here I'm not gonna use any spacer plates I'm clamped down directly to the big thick aluminum block I've got a slight gap in there most of that gap will will draw shut just from these two Intex I'm doing the same thing I'm putting just a little bit of extra metal a little few extra dabs on each end again I'm using o45 filler metal and I'm welding that first run and it's requiring 70 amps at full pedal and honestly I wish I had five or ten more amps here I can tell it's just I'm having to go a little slower to be able to ensure penetration however you can kind of see that it's pulling the heat out a little bit better a little bit less discoloration more a little bit more gold and blue in there where I started that doesn't really matter on carbon steel it's just something to notice pay attention to look how I'm shaking here I guess the point here is that you can shake and still make a decent weld but I don't know if I wasn't propped up or I was in a jam with the camera in my way or what but man when I was editing this I'm just noticing I really got the shakes now this piece got full penetration end-to-end as well it looks a little different it's much more silver and shiny because it was shielded better by being clamped ground directly against that chill bar probably a little less distortion also because it pulled the heat out but it's not better it's not worse it's just different if you're going to use chill bars you're going to need more amperage chill bars as well as back-stepping can really help in limiting Distortion well that's it for this week a nice short and sweet video I support these videos with my online store at weld monger dot-com you saw me using this Furyk number eight clear cup in this video those are available on the store what that does for me my eyes aren't what they used to do and it just sort of lights an extra inch or so ahead of me lets me kind of see where I'm going I need that all right well monger comm see you next time you

Channel: weldingtipsandtricks

Views: 140,625

Rating: 4.9523311 out of 5

Keywords: backstep welding, tig welding technique, tig welding tips, tig welding, gtaw, gas tungsten arc

Id: bto3s66zf38

Length: 6min 13sec (373 seconds)

Published: Tue Feb 27 2018