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Top Shop Tips: Welding Aluminum

Dave learns how to weld aluminum from Lincoln Electric welding instructor Karl Hoes. From Machinery Show 713

Mon, 12 May 2014|

Most welding chores on the farm involve steel. And we've all learned some bits and pieces whether good or bad about how to weld on steel but now we start seeing grain boxes. And other items showing up on the farms that are aluminum. And suddenly now, our welding are not sticking like they used to do for today on top shop tips -- gonna talk with welding expert Karl Hoes of Lincoln electric. We're gonna talk about this odd animals that showing up in the metal piles and and on wheels in the farm. And that's aluminum and guys -- complained to me a lot. Gosh it doesn't seem my my well. -- seem to work at all. It's not the same as stealing your telling me. It's a different animal you're you're dealing with something different everybody grows up -- steal everybody learns -- wild on steel and aluminum is just different. Now let's talk about the heat so I have to guess then if you're going to be welding aluminum you don't wanna have a whole lot of high heat in this thankful. Believe it or not he would do you need a lot of heat input to melt the aluminum because it has such high thermal conductivity. You put the heat to it it's a super highway for heat. Aluminum conducts the away. But then ask -- -- gets saturated with -- it changes in the behaves differently so it takes a little getting used to. Karl you mentioned the oxides that build up from the welding that are in the weld itself. What are we talking about their focus really on the aluminum itself aluminum reacts instantly with the air that we breathe. The oxygen in the air combines with the aluminum and it forms a chemical compound on the surface of the aluminum it's called aluminum oxide. In a little relax as would grinding wheels are made out in -- paper you know every -- you see its aluminum accents are very abrasive. Very hard material -- 3700 degrees it melts a thousand degrees hotter that steel. It's a second hardest material known to man as far as a natural occurring material next to diamonds. So here -- this disparity right you have aluminum which has a lower melting temperature -- the steel and aluminum oxide that has a higher melting temperatures. Where that's the challenges that on the backside is actually a form of rocks but it's a tightly and hearing -- and once that surface rust on the aluminum doesn't prosper and that's why don't have to paint aluminum sometimes. Oh that's the kind of hazy it when you first get sent -- -- that shiny bit -- while that out of coming over time that oxide layer grows thicker the problem backside is aluminum oxide actually absorbs things into it. And hydrogen from the air and moisture humidity over time gets you into that oxide and even though when you well you remove the backside with a positive polarity of the I have in the -- cycle in this case of aluminum welding -- loan money see the positive clarity scripting oxide off. The stuff that's in the oxide goes right into the weld now that's hydrogen. Also you're actually porosity you're introducing pollutants right -- right when you read well on this. That causes like he actually cut through that well this is a lot of times full of holes and where does that hydrogen goes right into the liquid weld -- when the well metal solidifies the hydrogen takes up space and that's. Pockets of total gas gas pockets cleanliness is even more important than it is with steel yes even a sharply mark I've noticed you know when you market aluminum. Even -- messes you up a little bit so while wiping it down with acetone and on chlorinated very really Important thing for important step any campaign has to be removed. It's in really give you all kinds of problems and not just right next to the well but away from the well always because aluminum conduct heat right into that paint. If -- if it is painted. In the paint catches fire and all black smoke comes up into your shielding gas it goes right down and you won't contaminates -- we know farmers -- crawling over machinery to -- Maybe in this case inside hopper and agreeing trailer. What -- suited to it to cure this problem with wire bunching up inside -- and one of the more economical solutions is go to school on. And this is a it's 250 apps pulled on here and what you do is use a small. School wire one house rules are allow -- fit in the back here and your only feeding now wire through rate. He's six inch straight okay so then right right here. Right the driver roles are right here. So you're just feeding at this distance here straight through and they need to step up from there you go to push -- down and that's your that's your top -- be doing a lot of aluminum won't use a push poll done. And that's what we're looking at here you were describing this and a push poll got. However there comes a bit pricing -- thing they're quite a bit more expensive but. Worth the investment if you're doing a lot of aluminum -- describe how that works it's actually it's. Polling the wire at the gun right yes you have a set a driver -- an -- that are pulling in at the back in the machine. We have another set of rivals pushing. So that's what I call -- push pull and missed the terms of speed of the wire if you feed into the well and right in this guy can be fifty foot long. So you can have your power source you're -- machine on the floor and have this up inside -- trailer working. Quite -- ways -- quite a ways away because you're pushing from the back in Poland from the front and you can -- quite a long distance now another thing we've been seeing more more. In -- shops and that's take well. Guys that. I'll learn them the benefit Kate especially when it and the standard stock. That's the limit when it comes through aluminum right. They -- wells -- thicker aluminum with take if you have a big enough machine Gagnon you know 275 EF 375 -- machine if you're willing thick sections of aluminum but when you need to control to -- a repair a little casting. Our some dinner aluminum intersections are taking this is the way to go. So when it comes to Feller medals are there common killer medals like. A lot of guys certainly have gotten that way with Nagin stick welding they usually keep a stock on hand -- handled most problems. Yes I would keep to too common filler medals on hand at all times and you'd be able to do probably ninety more than 90% of your welding the would -- on a farm. And that would be 5356. Which is Elena magnesium. And 4043 which is -- basilica. Now I noticed that some of these filler medals we've got a number pressed on the hand this is 4045. 4043 all 4043 -- it is small I mean I -- now one of these days sometimes are hard to read. But what if you don't have a number on them because -- look at this how would you tell the difference between that and volatility talked about if you only have two of them on hand right I can tell by bending some time. That we've done this before and 4043 bands really easy oh what is -- -- right if you go to what 5356. And I think that's what I got here. Suffered oh it's a little more so that you know right away from him and any other way as I dropped on the floor. And the 5356. She frames. Him 4043. -- all I see so I have only those two I can tell one from the other without even getting my vitals. What we get to welding aluminum it's not the same as Steele either because you're dealing with a metal that first of all. Dissipates heat but also melts at lower temperature Heidi world that. It changes as you well that's why it's really nice to have that put -- in the beginning a well. You actually got to get more heat into that aluminum and you can do that by traveling slower staying there a little longer before you get an -- the filler metal. And then as you get into the piece that piece starts to get saturated with heat. It conducts heat away from the wells and a slower pace so well is it becomes liquid and usually you start woman along pretty good speed. When you get near the end of the well that plate might be heated up this if you -- smaller plates could be heat up to 6700 degrees. And you no longer need get 130 -- you have when you started out you might drop on the fifty camps. You were telling me that what you do it the into the well. Well this also crucial to prevent the crack for reform and Witten user okay well what tig welding you have that put panel when I get to the end of the Apollo. Her to the end of the well when I wanna stop welding instead just letting off that foot -- -- torch away. Let off the foot pedal -- and freeze at call back up and come down with a little bit. Still lower current and they have a little extra filler metal on top and Phil black crater -- so it's convex. Instead -- case. In May and -- was -- -- sometimes doubling back at the end. And you know get to the end of -- well bubble -- can go back into the -- -- the crater in the middle of the well instead of at the end. Carl you're all set up to weld you actually need to set the machine though much like you do with steel. Obviously this is something that we tried to help people over the years. How do you determine and aluminum because it is that much radically different. Welding process. Say the difference between what we have years to really. Six structural aluminum. Well the guidelines in the back of the book and also on the covers of the welding machines all -- actually show you. 18 aluminum they give you different sizes a wire you can use what you're what you're looking for a 125 -- -- 150 apps so something like this. If I can do -- -- -- 14 because you're right in that range right Kate so you jump up to. Creates aluminum. You're starting to look at 240 to 300 camps and this is some half inch aluminum so you're looking at 360 to 380. That's a big -- change -- actually gonna need a bigger machine while the sticker material this is where heavy industrial machines come in when your welding something like this. Well it sounds like setup is so crucial and a lot of that information is available not only on your welder. But also in the book that you're holding up here Lincoln provides a great guy don't Illumina for our gas metal arc welding. And you can get these books either order malign or find the information online at Lincoln Electric dot com check. Right our needs can be actually dollars on your computer and PDF format instantly so you can get them right away -- could send away for the copies like I have here which is always a good thing to have in the shop anywhere great to be Evelyn resource I mean is that the -- things off. Well I know a lot more about aluminum welding I did before and I'm even willing to take it on. Sometime next time when I'm out my brother shop full thanks for that information Carl. Okay I'll see you next week on another pop shop tour.