Mig for thin 1.2mm plate bodywork

[Jelly_Sheffield]

0.8mm wire and a series of tack welds is usually how car body repairs are carried out. Around 120amp or so, decently hot for the tacks to run nice.

I have never once seen a car welded as a continuous weld so this 30 amp thing makes no sense to me

You can get a continious weld going if you make a joggle at the edge of the repair piece (effectively adding a backing plate), but it takes phenomenal concentration...

I agree that if tack welding you want the wire feed set high enough to get a decent amperage to ensure proper penetration...

My normal settings on a fully manual machine would work out around 73-90A, at 29V.

The little synergic welder I started using prefers to run about 19V and 110A for the same material, and it took some getting used to.

 

[JOEPRO]

You can get a continious weld going if you make a joggle at the edge of the repair piece (effectively adding a backing plate), but it takes phenomenal concentration...

Heat is also your enemy when welding thin car bodywork. Hence why I use a series of tacks and a air blow gun to cool them quickly as I go.

I have no doubt I could run a full bead, especially with a joggled edge but the heat would destroy and warp most panels doing that!! The weld will also pull and shrink the surrounding meral.

This is as close I get to beads on thick Merceded coupe cill steel with R Tech 180

 

[GC77]

Agree with what's been said so far.....the older technology machines are transformer based and for panels you ideally want a 90 to 160 (max) amp machine (if your looking at migs) - much higher amperage machines such as 180 amps plus) won't have flexibility at the bottom end. Some of these were constructed with car bodywork in mind, so there is sometimes a clue in the name eg autostar, autoweld. I've used a Clarke mig pro 90 (gas) with 0.6 wire for years and it's range for thin stuff is great...and it will also do 4mm if correctly prepared. Don't bother with flux core really bc of the amount of cleanup of spatter after it - nor pub gas either IMO. Otherwise your into the inverters, and these days you can take your chances with the Amazon/eBay products.....some of which offer 2 or 3 year guarantees.....but then need to return to China for a fault (unless you buy a brand with a UK base... which limits the range of possible machines quite a lot). It is a minefield really and there are few straight answers I'm afraid.

Thanks

 

[jo1010]

0.8mm wire and a series of tack welds is usually how car body repairs are carried out. Around 120amp or so

this 30 amp thing makes no sense to me

Put welders in a room and someone will disagree....at least in part . Surely on thin stuff 0.8 wire can put more heat in the joint on thin metal.....yes it works but I find I can step down the voltage using 0.6 ...and put less heat in the joint so less chance of warping or pulling. (My personal experience but not on rtech).
The 30 amp thing makes some sense - its a pita to try to use 40 amp machines on thin stuff - their voltage range usually is too high and too much heat ends up in the joint, and no doubt there there are some 30 amp machines that do better than others with thin stuff....all I'm saying is that there are a lot of variables....and general rules often don't make much sense....

 

[jo1010]

My normal settings on a fully manual machine would work out around 73-90A, at 29V.

The little synergic welder I started using prefers to run about 19V and 110A for the same material, and it took some getting used to.

...and I bet you find your synergic is easier to use with that lower voltage....

 

[Jelly_Sheffield]

...and I bet you find your synergic is easier to use with that lower voltage....

Nope...

Found it a lot harder to use until I adapted to it, now both are fine but need different techniques.

With a low voltage the arc is more prone to wandering and you don't have the same arc force to push metal where you want it with the torch.

Yes that reduces your chances of immediately blowing through, but it also makes it harder to get consistent penetration which means you have to linger a bit longer to make each tack giving you more chance to spend too long and put excessive heat into the work.

Also when trying to get into awkward corners, push metal into a pinhole, or precisely put a tack into a small hole, the arc force of a higher voltage helps... Eventually I got to the point where I would "save up" all those tasks, and manually crank up the Arc-Force settings on the synergic welder to do them.

Ultimately there's lots of effective ways to do this, but it's what works for you that matters.

 

[GC77]

Took the jump and bought a StaticArc 140D. Let’s see how it goes.

 

[eddie49]

Could be this one:

MIG 140D Inverter Welder 4in1 Synergic MMA TIG LIFT Gas Gasless ARC Welding 140A

STATIC ARC WELDING SUPPLIES, MIG TIG MMA ARC WELDERS FILLER RODS ELECTRODES WIRE TUNGSTEN CONSUMABLES MB15 MASK HELMET GLOVES CLAMPS TORCH 14AK PLASMA CUTTER PT31 GAS REGULATOR GASLESS FLUX WIRE FEED ROLLER CABLE ANGLE GRINDER BENCH SANDER DRILL POLISHER STEEL FLAT ROUND SQUARE ANGLE BARS SHEETS...

staticarcwelding.co.uk

Looks good, has a detachable Euro torch and a metal wirefeed assembly.
I would be interested to know how the torch polarity is reversed ( Positive for solid wire with gas, Negative for gasless fluxcore ), since it looks like the power input from the inverter to the brass Euro socket is a solid copper busbar.

 

[tigdlo]

I would be interested to know how the torch polarity is reversed

There is a cable on the front panel just below the euro connector, I'm assuming that will plug into one of the dinse sockets, they have cropped the images so it doesn't show what I would assume is a dinse plug.

 

[GC77]

Could be this one:

MIG 140D Inverter Welder 4in1 Synergic MMA TIG LIFT Gas Gasless ARC Welding 140A

STATIC ARC WELDING SUPPLIES, MIG TIG MMA ARC WELDERS FILLER RODS ELECTRODES WIRE TUNGSTEN CONSUMABLES MB15 MASK HELMET GLOVES CLAMPS TORCH 14AK PLASMA CUTTER PT31 GAS REGULATOR GASLESS FLUX WIRE FEED ROLLER CABLE ANGLE GRINDER BENCH SANDER DRILL POLISHER STEEL FLAT ROUND SQUARE ANGLE BARS SHEETS...

staticarcwelding.co.uk

Looks good, has a detachable Euro torch and a metal wirefeed assembly.
I would be interested to know how the torch polarity is reversed ( Positive for solid wire with gas, Negative for gasless fluxcore ), since it looks like the power input from the inverter to the brass Euro socket is a solid copper busbar.