Fabricating gates with a mig welder

dal · 5 Jul 2022 at 16:25

Hi all, at some point I want to make a pair of gates out of 40mm mild steel ( prob 3mm thick) box section. Do you think a mig welder would be up to the job, I've done a fair bit of mig welding when I was younger but that was on cars, from what I remember mig can penetrate 3mm which I guess would be ok.
Mig welding is the only welding I've done so would be the obvious choice for me but if not a mig welder any recommendations ?

Cheers

JonRGV250 · 5 Jul 2022 at 16:33

A mig will be fine for 3mm, and some.

sovietspybob · 6 Jul 2022 at 09:56

Yeah 3mm will be no problem at all, i think you can generally go up to 5mm with a home MIG, 5mm+ i'd be using an arc welder at home.

If you've done MIG before i'd stick with it as it's definitely the easiest out of the ones you can do at home, i've got MIG and ARC and ARC requires quite a bit more skill, saying that it's my go to 90% of the time as it's so much easier to setup as no faffing around with gas and spools of wire, just put a rod in and go for it.

DO you have a welding set already? If not that does make it a harder choice as a decent home MIG might be getting on for £300 nowadays where you can get a decent ARC welder for £100

dal · 6 Jul 2022 at 11:43

sovietspybob said:
Yeah 3mm will be no problem at all, i think you can generally go up to 5mm with a home MIG, 5mm+ i'd be using an arc welder at home.

If you've done MIG before i'd stick with it as it's definitely the easiest out of the ones you can do at home, i've got MIG and ARC and ARC requires quite a bit more skill, saying that it's my go to 90% of the time as it's so much easier to setup as no faffing around with gas and spools of wire, just put a rod in and go for it.

DO you have a welding set already? If not that does make it a harder choice as a decent home MIG might be getting on for £300 nowadays where you can get a decent ARC welder for £100

Hi, no not got a welding set yet, I was looking around £130 for a mig, didn't want to spend loads, I've only got a few jobs to do with it.

sovietspybob · 6 Jul 2022 at 12:26

dal said:
Hi, no not got a welding set yet, I was looking around £130 for a mig, didn't want to spend loads, I've only got a few jobs to do with it.

I would say be careful of cheap MIG's, the cheap gasless ones tend to be a bit... well... not very good. You might struggle to get decent welds with a cheap flux core MIG. If you're only wanting to spend that much i'd recommend looking at an ARC welder, i've got a cheap (was just under £100 earlier in the year) 160amp Hyundai one and i've found it really good but like i said before there is more of a learning curve but they are very handy machines as you can weld anywhere with them pretty much.

gc123 · 6 Jul 2022 at 19:14

as above have several migs including gasless from before i retired, but bought a cheap chinese arc welder from ebay for about 60 quid and some rods now easier for me to use than faffing with wire and gas etc.
been 35 years since i arc welded and guess its like riding a bike within about 20mins i was back into the swing

now prefer it to mig

Rich1988 · 6 Jul 2022 at 19:18

If you are going cheap go arc. I have never seen a gasless mig give consistent good welds.

dal · 6 Jul 2022 at 20:36

I've only ever used a arc welder once when I tried my mates one out, I remember the stick kept getting stuck to the metal, that was about 20 years ago though.
How long does it take to learn arc welding so a reasonable standard.

sovietspybob · 8 Jul 2022 at 09:32

Yeah there is much more of a knack with ARC, like you say rods sticking is pretty common. you start be tapping gently until it strikes an arc, you get used to your own machine so it becomes less of an issue. Also as the rod burns down as you're welding you have to keep moving it closer, when i first started i could lay down a really nice looking weld then realise it was about 1cm in front of where it needed to be and nothing was actually stuck together!

But saying all that it's still my go to form of welding as it's just so quick and easy to setup, i'd say it took me a couple of hours to get to grips with it and start doing 'work' with it after just playing around with scrap metal, obviously the more you do the better you'll get. Just make sure you watch a few youtube videos and you'll be ok as long as you're not totally cackhanded.

Chris Wilson · 9 Jul 2022 at 16:09

Stick for really heavy or galvanised stuff unless you have a 3 phase supply. (Although welding galvanised steel is really not good, stick will give acceptable results, MIG and TIG will not)

MIG for better looking welds and more finesse and control.

TIG for aerospace, motorsport or plain show off welds, and welding aluminium alloys, stainless and the more exotic ferrous and none ferrous metals.

Gas isn't very popular these days, probably because of the cost and hoops to go through to hire acetylene. Forget oxy propane, nothing like enough heat for welding, barely enough for brazing heavy stuff in a timely manner.

I don't have stick, although my TIG would be able to stick weld, too. I also have gas and MIG. MIG is what i use for general fabrication, TIG for aluminium, stainless and the odd bit of Inconel.

A USED branded MIG will be far better with a much better duty cycle than some new Ebay Chinese junk. Just like compressors...

I have a 180 Amp single phase MIG and it'll do 3/8 inch plate OK. I've VERY occasionally done 1/2 inch plate with it by pre heating with oxy acetylene, but it's tedious and not really practical for anything other than small one offs.