Basic amps / wire thickness question.

[julianf]

Current setup -

Portamig 215 welder
Parweld m15 torch
0.6 wire

When welding up thicker stuff (3-4mm) I've managed to set the m15 torch on fire before.

I have to make some long welds on 6mm angle to 3mm box.


I'll buy a M25 torch. I assume I should just go for 1.0 wire, right?

I get by with 0.6 for most stuff (wasn't chosen, just happened to get a 15kg roll of it with the welder) and I'm thinking 0.6 to 0.8 won't really be a huge difference and I should just go for 1.0?

Thank you

6mm to 3mm -

3mm -

 

[a111r]

Try 0.8, that should do everything.
Doesn't seem much but 0.8 compared to 0.6 has nearly double the csa (16: 9)

 

[julianf]

"Try"ing will cost me about £50 or something in wire, tips, postage (i have nothing but 0.6 here)

If its 0.8 that i need, then ill go for that... i just cant quickly load up some and give it a go, if you see what i mean?

 

[julianf]

I thought there would be loads of these tables about, but, surprisingly, they seem few and far between (in metric at least, and my brain cant do the conversions on the fly!) -

 

[Dcal]

0.8mm will be my choice for 3 or 4mm.

 

[julianf]

0.8mm will be my choice for 3 or 4mm.

3mm going to 6.35mm?

I dont know if you choose by the thick side or the thin side...


Ive never had to think about this before - i just grab the welder and spin the dials until it works! But clearly what i have wont work now with what i want to do, hence having to work by something other than trial and error!

 

[Munkul]

Go by amps for wire size, and match the amps to the size of steel you're welding.

A 3mm to 6mm weld should have a leg length nearer the 3mm than the 6mm, and the amps will be ideally set around the 4-5mm range to get extra heat into the 6mm.

0.8 will do everything you want, its usable range goes up to 150 amps, higher if you push it but not reccomended.

 

[500e]

Have a look here Julian
https://www.mig-welding.co.uk/calculator.htm

 

[julianf]

Have a look here Julian
https://www.mig-welding.co.uk/calculator.htm

That does not really have a comparison between amps and wire diameter.

 

[backpurge]

0.6 wire is nowhere near large enough, 0.8 or 1.00mm is what you need

 

[Mark 2]

I think it is about deposition rate. Surprisingly, 0.8 will put down nearly twice as much as 0.6 if my maths is correct.

 

[julianf]

To be clear -

I have to buy one or the other (0.8 or 1.0)

I don't want to buy both.

I have 0.6 currently.

I felt that 1.0 would do for the job in hand and give me more flexibility in the future.

But there's no point in getting 1.0 if 0.8 is what I need currently.

 

[Mark 2]

.0.8 from me.
(strictly come welding)

 

[metalmelt]

I would switch to an MB25 and use 1mm wire, the 25 will handle around 250 amps without issues and they are more suited to industrial welding so more in abundance in quality brands, 0.8 realistically welds to around 160-170 amps and you have a 215 amp machine so both the torch and wire will cope with that and give you the flexibility you require along with additional safety.

 

[Munkul]

To be clear -

I have to buy one or the other (0.8 or 1.0)

I don't want to buy both.

I have 0.6 currently.

I felt that 1.0 would do for the job in hand and give me more flexibility in the future.

But there's no point in getting 1.0 if 0.8 is what I need currently.

If you feel the need to weld any bodywork panels at all, then 0.8 is a better choice. 1mm just doesn't run well at all under 80 amps.

 

[julianf]

If you feel the need to weld any bodywork panels at all, then 0.8 is a better choice. 1mm just doesn't run well at all under 80 amps.

I wasn't planning on throwing out the 0.6. I'll still have that and the mb15 torch whatever else I buy...

 

[Mr Roo]

"Try"ing will cost me about £50 or something in wire, tips, postage (i have nothing but 0.6 here)

If its 0.8 that i need, then ill go for that... i just cant quickly load up some and give it a go, if you see what i mean?

0.8mm wire will be more than sufficient for the job. I use a mig with 0.8mm wire for near enough everything in my own workshop.

 

[creepy]

Might be worth checking what your feed rollers can support 0.6 and 0.8 is a common pairing, then 1.0 and 1.2 but I would be going with 0.8, if heavier "stuff" was to be the norm then poss move to 1.0 but 0.8 is a nice std for most light work.

 

[Turbo]

I use 0.8 for everything, from body panels to thick plate up to 10mm.

Think of it this way - you can stick weld any thickness of metal with a 2.5mm rod, but you will need more passes & joint prep on thick plate. 3.2 or 4mm rods will make things easier but you will need a welder that can run them nicely.

Another thing to consider - is your welder able to run 1mm wire properly? To get your full 215a you will need a 32a supply and the full 230v supply. If your workshop is a long way from the incoming mains supply you will suffer significant voltage drop that will affect the welder output. Put it this way - you would get better welds running the 0.8 at its upper limit than trying 1mm at its lower limit.

I would go for the MB25 & a 0.8 setup if I was you.

 

[metalmelt]

If you feel the need to weld any bodywork panels at all, then 0.8 is a better choice. 1mm just doesn't run well at all under 80 amps.

Munkul, he already has the 15 and 0.6 wire, Julian wanted flexibility and with a 215 amp machine and the 25 along with 1mm wire he would get this as this allows him to switch to the 15 with 0.6 and go to the 25 with 1mm wire so he wouldn't be running it at under 80 amps and he could safely use the full capacity of his machine safely.