Learning to weld was a massive part of my whole first gravity racer build. I’ve always fancied a go at it, and when I moved into a house that had a garage perfect for workshop use, I finally had the chance to get a welder and all the necessary tools and have a proper crack.
Many years back I’d bought a MIG welder that I had a go with for a bit, but this time I wanted to try TIG welding. I’d read that it was more expensive and more difficult to learn, as well as being slower, and in many ways this is all true. But TIG welding has several advantages that make it super worthwhile for me. What follows is my experience of TIG welding. Of course, your mileage may vary, and there’s plenty more info online, most of it from more experienced welders that myself.
It’s clean. TIG welding is almost completely free from spatter, sparks, smoke and fumes. Basically, you could do it at the dinner table in your underpants, if you were so inclined. When you’re in a workshop that’s not soleley used for metalworking (I have wood and paint and other stuff in there) this is really useful as it’s difficult to start a fire. It also means that I can share the workshop, as long as the other person doesn’t look directly into the arc.
TOP TIP: It can be easy to forget that TIG welding still makes the metal REALLY FUCKING HOT because you’re not getting showered in sparks and cack. Don’t forget. It definitely does.
Strong. TIG works on the fundamental principle of melting the two parent metal surfaces together, and adding filler as a supplement to that. With MIG it’s possible to have a lovely looking weld bead that’s not actually sticking anything together properly and falls off when you bang it with a hammer. With TIG, it’s got a much higher chance of being strong even if it looks a bit messy. Hence the use of TIG and stick welding (no MIG) in strength critical applications such as the nuclear power industry.
Power range. TIG welders can go down to really low power levels, which means that you can weld very thin metal. If you look online you’ll see plenty of examples of two razor blades getting welded together, or two soda cans. Try that with MIG! My car is made from 14 gauge (1.6mm wall) steel box section, and with a bit of practice I almost never blow holes in the metal with the welder set to around 70 amps. The upper power level is dependent on the model you buy, but going up to 120 amps I’ve welded steel up to 6mm thick, which is the top end of what you’ll encounter building gravity racers, I would have thought.
Flexible. TIG welding can weld all kinds of different metals, including aluminium if you get a welder that offers AC power as well as DC. All you need to do in most cases is to change the filler rod that you use. Use a mild steel filler rod for welding mild steel, use an aluminium filler rod for welding aluminium. Simple. TIG can even weld dissimilar metals together, either by using rods that are a chemical mixture of the two different metals (for welding mild steel to stainless) or by using a method called TIG brazing, which uses silicon bronze rod to “glue” the parent metals.
Aesthetic. TIG welds (once you have the skill!) can look really nice. Of course, this isn’t massively important, but hey – it’s worth mentioning. If you take a lot of pride in your welding and you care about producing nice looking work, TIG welding will allow you do that. Eventually.
Expensive. TIG welding uses Argon shielding gas, which is not especially cheap. I use the Hobbyweld system, which basically means you buy the bottle (around £50) and then pay for each refill (again, around £50). I used two tanks of gas, welding my frame together. It’s not mega money, but more expensive than MIG welding where you only need CO2, which is cheaper, or you can use flux cored wire that doesn’t need gas at all.
Fussy. TIG requires the metal you’re welding to be spotlessly clean for best results. I always clean my steel with acetone, and then prepare all welding surfaces with a grinder and flap disc to get right down to clean and shiny bare metal. If you skimp on the prep, the welding just doesn’t go well at all. When you’re welding, you need to give the area a good going over with the wire brush each time you stop and restart too. TOP TIP: brush the weld before it cools and it comes clean much easier!
Indoors Only. Because TIG welding is extremely dependent on the Argon shielding gas, you can’t easily weld outside, or anywhere where there’s wind. If you want to (or have to) weld outdoors you’ll need to construct some kind of wind break. If you don’t, and your shielding gas is getting blown away, your welds will be an epic explosive disaster of gargantuan proportions.
Slow. TIG is pretty slow when compared to MIG welding – it takes much longer to weld runs of any great distance. If you were doing a lot of long runs, especially in areas where ultimate strength isn’t a consideration, then MIG is usually a better bet if you’re up against the clock.
Hard. TIG is a steep learning curve and until you’ve got the hang of it it can be a struggle. There are a million tutorials online (and I’ve watched most of them!) but there’s nothing like having a go and working it our for yourself. I find the hardest past of TIG is getting into a comfortable position to allow the range of movement and steady hands, but hey, you’ll almost certainly come to the same conclusion when you give it a try.