.6mm or .8mm sheet with Clarke pro 90?

[rooz121359]

Hello,

Trying to weld some bits and bobs on my vehicle.

I have a clarke pro 90 that I used with 1.0mm sheet before without any issues.

Now, I have some 0.6mm sheet as it's a LOT easier to shape and bend.

However, when I was running some tests lastnight, I realised I blew some holes in the 0.6mm sheet.

I played around with the wire speed and the amps and the gas... I couldnt figure out what was the cause of the holes!

I never had this issue with 1.0mm sheet!

Is there any specific settings for clarke pro 90 (wire speed, gas and amperage) to use for .6mm sheet?

Or should I simply ditch the 0.6mm sheet and use 0.8mm sheet?

Thanks

 

[carbon]

What size wire are you using?

 

[rooz121359]

What size wire are you using?

Sorry I should have said.

I'm using 0.6mm wire with CO2 + Argon gas.

 

[Robert Weaver]

What's causing the holes is too hot a puddle for the gauge of parent metal. Heat input is melting a pool greater than 0.6mm deep, hence the molten metal drops through. Surface tension on the edges pulls the hole wider.
The 1mm sheet is thick enough to have unmolten metal beneath the pool, so defeating gravity.

Backing bar, lower input (volts, wfs) or pulse probably the options. The second and third might eliminate the pro90 on this material gauge.

 

[Dozzer]

What @Robert Weaver said, plus try turning down the gas.
With really thin material many people use lots of individual spot welds, not a long run.

 

[Robert Weaver]

Yeah, forgot. Lots of successive overlapping spots giving a bead.

 

[roofman]

Very hard to run a bead on car body stuff using 1mm or under metal...i always spot and let the next spot absorb heat from the last to stop burn through, if you have your welder set right and the contractor pulling the power in is not lazy then you can kinda spot fast enough to seam weld from a pretty basic welder. Here is a mower repair i did using the same principle.

 

[Popcorn]

Mig Welding Technique for Thin Metal

Techniques and a video showing how to weld thin metal using a stitching technique.

www.mig-welding.co.uk

 

[moleb]

I find this on sub 1mm, it needs a softer start than most cheap sets have and consistency. Beware folk who say they can weld thin with anything, typically they are meaning 1mm or 1mm patch over something thinner. The more expensive the mig, the lower the start amps will be. 20amp sets start at around £1500 and go upwards, the IFL MP200 has a soft start, for example, the Lincoln 200 starts at 20 as do others. Before you go there, it's counter-intuitive but watch this guy turn it up and push more heat in for decent results:-

Finally, here's a test of cheap to expensive where they actually test on thin sheet rather than banging 2 bits of 3mm together. You can see the difference between cheap and expensive on .8mm sheet at 11:43 here:-

 

[rooz121359]

I find this on sub 1mm, it needs a softer start than most cheap sets have and consistency. Beware folk who say they can weld thin with anything, typically they are meaning 1mm or 1mm patch over something thinner. The more expensive the mig, the lower the start amps will be. 20amp sets start at around £1500 and go upwards, the IFL MP200 has a soft start, for example, the Lincoln 200 starts at 20 as do others. Before you go there, it's counter-intuitive but watch this guy turn it up and push more heat in for decent results:-

Finally, here's a test of cheap to expensive where they actually test on thin sheet rather than banging 2 bits of 3mm together. You can see the difference between cheap and expensive on .8mm sheet at 11:43 here:-

Unfortunately I cant buy an expensive welder. I have to use what I already have which is a clarke pro 90.

The pro 90 amperage is between 25 to 90 I think so not that bad I reckon.