So I bought a used MIG welder...

[slim_boy_fat]

@RJY Firstly, welcome to the forum.

First thing I'd do would be to give your machine a good clean out to get rid of all the cr*p inside. It may just be body filler dust but there could also be grinding dust in there too, given that it's come from a body shop, and the electrics don't like that if it's allowed to build up.

Good luck with the learning curve.

 

[RJY]

@RJY Firstly, welcome to the forum.

First thing I'd do would be to give your machine a good clean out to get rid of all the cr*p inside. It may just be body filler dust but there could also be grinding dust in there too, given that it's come from a body shop, and the electrics don't like that if it's allowed to build up.

Good luck with the learning curve.

Thank you. Is there likely to be any nasty big capacitor in there to zap me, I wonder? Soft brush and vacuum?

I had better not actually use it in the kitchen, I suppose. Sparks would fly!

 

[hotponyshoes]

These Hobbyweld Ultra bottles look good, but as you say, £190 deposit, ow!

From their website: capacities (standard temperature and pressure, something else? I don't know):

Original 1.4 m3 gas 137 bar
Plus 4.86 m3 gas 230 bar
Ultra 6.34 m3 gas 300 bar

Unfortunately SGS does not state a "gas volume" (at whatever pressure), only that it's "intended fill capacity" is 200 bar so presumably roughly 15% less gas than the HW 20L one.

The contents of gas is just the bottle size multiplied by the pressure.
So a 20l cylinder at 200 bar would be
20x200=4000. Divide that by 1000 to give you 4.0m3 of gas.

The deposit is a one-off cost but the gas is an ongoing expense.
If you work out the cost of the gas per m3 you can see how it works out cheaper in the long run.
Although the Ultra deposit is nasty and you also need to pay for the gas at the same time. The inbuilt regulator is decent but if you already have one it's not really saving you anything. Quick connections are only a few quid anyway and not really much use if you only have one welder.

 

[slim_boy_fat]

Thank you. Is there likely to be any nasty big capacitor in there to zap me, I wonder? Soft brush and vacuum?

I had better not actually use it in the kitchen, I suppose. Sparks would fly!

I'm not into elektrickery , but if you leave it without power going to the machine for a while I think any capacitors would have discharged - maybe some of our 'sparkies' will comment/advise. Vacuum would remove the worst of it before delving into the innards.

 

[Munkul]

You can do a LOT of MIG welding with a standard 20l bottle at 230bar.

I would tool it up for 0.8mm steel wire, it will be its most comfortable working size. 0.6 is fiddly.

 

[Turbo]

You can do a LOT of MIG welding with a standard 20l bottle at 230bar.

I would tool it up for 0.8mm steel wire, it will be its most comfortable working size. 0.6 is fiddly.

+1 on that.

My 20l bottle has lasted me 2 years so far with only occasional hobby welding.

 

[northwest]

I would tool it up for 0.8mm steel wire, it will be its most comfortable working size. 0.6 is fiddly.

.8mm wire seems to me the best all round size and I know a good many who use .8mm almost exclusively for everything, I am no welder by a long shot but I use .8mm wire and I too use it for every job I point the mig at, with some success too on occasion.

 

[bourbon]

Welcome from me as well. As @slim_boy_fat says, a good clean will help loads, You can buy replacement liners easily enough and new tips and a shroud would be a good start. Then lay some beads down on various thicknesses of metal to get the 'feel' of the machine. Sorry, can't help with the gas as my mig is set up for gasless

 

[Easywelder]

Welcome, are you in Milton Keynes? I‘m near Dunstable you would be welcome to bring it down and try it out here I have gas, usually use agoshield universal. I run a cebora 300amp bought second hand a number of years ago and I’ve never had an issue with it, great machine.

 

[Robert Weaver]

Can you point me at the guide and settings you mention, please? There is so much information here!

https://www.mig-welding.co.uk/tutorial.htm

 

[RJY]

Welcome, are you in Milton Keynes? I‘m near Dunstable you would be welcome to bring it down and try it out here I have gas, usually use agoshield universal. I run a cebora 300amp bought second hand a number of years ago and I’ve never had an issue with it, great machine.

Sorry, missed that. Thank you for your kind offer. I am hoping to get a regulator tomorrow, and I have some gas now; I will see what happens, and let you know!

 

[julianthegypsy]

I must be plus four saying get a roll of 0.8mm wire. Usually the feed roller is reversible and will be marked .6 and.8mm. old wire is also prone to rusting, even with the copper coat, and it can cause problems like intermittent slipping, which is really frustrating, especially when you don't know why. You often can't see the rust very clearly either, but the wire should be dead smooth if you slide it through your fingers. If it isn't, junk it!

 

[RJY]

I must be plus four saying get a roll of 0.8mm wire. Usually the feed roller is reversible and will be marked .6 and.8mm. old wire is also prone to rusting, even with the copper coat, and it can cause problems like intermittent slipping, which is really frustrating, especially when you don't know why. You often can't see the rust very clearly either, but the wire should be dead smooth if you slide it through your fingers. If it isn't, junk it!

"old wire is also prone to rusting, even with the copper coat".... yes. As long as the coating is intact. If there's a scratch, in the presence of air and water, the copper coating will cause the steel under to corrode faster (electrolytically). They copper coat car brake pipes!

I'll give 0.8mm a try in my testing which I hope to start this side of Christmas. It's too frizzing cold outside to deal with what I actually want to deal with now!