First time MIG welding after ARC welding since 1999

[Franknstein]

So, as the title says, I've been ARC welding for 17 years, my dad taught me when I was a teen and been doing it as a hobby ever since. Used to build security bars and gates for money in South Africa in the mid 2000s, and in 2012 built a 22ft boat trailer... But in all that time, never touched a MIG and always wanted to.

A recent purchase of a 328i BMW to build as a track car prompted me to buy a MIG (GYS Smartmig 160) - as I'm going to be doing some work on the exhaust and will definitely have further use for it welding thinner stuff, like bodywork (although the car is rust free!)

Very happy with the welder, bought it 3 weeks ago from a member of these forums, and had good service.

Got a hobbyweld cylinder and rigged it all up.

First use, what can I say - blown away. I could probably do with more time fiddling the settings and getting used to the new format, but what a difference in so many respects compared to stick welding! No more rods sticking to the piece, slag chipping, stopping to change rods etc... and the most impressive thing I have found in my 10minute use of the new machine is its ability to bridge two pieces of steel which sit 8mm apart from one another without burning through! I could never do that with my arc welder. Probably not best practice to do that sort of thing, but nice to know you can. Attached pic, bottom left weld shows the pieces welded which were 8mm apart... excuse the lack of cleaning of the pieces, I just dove right in as I had very little time to test it out.

Anything glaringly obvious from the picture that would suggest I need to adjust something for better outcome? Heat/speed/technique etc?

Also, one other question. When you're done for the day and want to purge the gas out the machine do you just shut the regulator and press the trigger until the gas is purged or is there a better way without wasting a foot of welding wire?

 

[cumbriasteve]

Glad you are enjoying your new machine, re purging..that's something many often debate, personally I don't do anything other than simply turn the bottle off.

 

[rich r]

I suspect all those years arc welding gives you an advantage over people new to welding starting with MIG, as you're already used to moving at a consistent speed and arc length and have a good understanding of how the weld pool behaves. Only now it's a lot less smoky and fierce

One day I'll convert from arc to MIG, but at the moment I wouldn't use it enough to justify buying a machine. However I'm sitting on here soaking up the advice for when the day comes...

 

[Richard.]

So, as the title says, I've been ARC welding for 17 years, my dad taught me when I was a teen and been doing it as a hobby ever since. Used to build security bars and gates for money in South Africa in the mid 2000s, and in 2012 built a 22ft boat trailer... But in all that time, never touched a MIG and always wanted to.

A recent purchase of a 328i BMW to build as a track car prompted me to buy a MIG (GYS Smartmig 160) - as I'm going to be doing some work on the exhaust and will definitely have further use for it welding thinner stuff, like bodywork (although the car is rust free!)

Very happy with the welder, bought it 3 weeks ago from a member of these forums, and had good service.

Got a hobbyweld cylinder and rigged it all up.

First use, what can I say - blown away. I could probably do with more time fiddling the settings and getting used to the new format, but what a difference in so many respects compared to stick welding! No more rods sticking to the piece, slag chipping, stopping to change rods etc... and the most impressive thing I have found in my 10minute use of the new machine is its ability to bridge two pieces of steel which sit 8mm apart from one another without burning through! I could never do that with my arc welder. Probably not best practice to do that sort of thing, but nice to know you can. Attached pic, bottom left weld shows the pieces welded which were 8mm apart... excuse the lack of cleaning of the pieces, I just dove right in as I had very little time to test it out.

Anything glaringly obvious from the picture that would suggest I need to adjust something for better outcome? Heat/speed/technique etc?

Also, one other question. When you're done for the day and want to purge the gas out the machine do you just shut the regulator and press the trigger until the gas is purged or is there a better way without wasting a foot of welding wire?

As Steve said its a heavily debated question as to whether you empty the lines or not. I always do Along with shut any valves and back off the pressure adjusters (if it has one) and I do it for 2 reasons.
1 to Take pressure off the regs and diaphragm. The pressure then stops at the bottle tap giving your reg a better chance of living longer. It also keeps the diaphragm moving/flexing If your taking off and putting on gas pressure which will reduce the risk of cracking/perishing. Again prolong its life.
The second reason is its a good habit. Although for inert gases it's not such a big deal for fuel gases it really is. If your in the habit of doing it every time you shut off a bottle for the day chances are you'll less likely forget when it's your burning bottles. You will waste a little bit more gas but it's fractional really. Regards to wasting wire simply take the feed roller pressure off so it's not feeding out while you press the trigger.