Limitations for use of 180 Amp Mig Welder ???

[knots43]

I am not new to welding however am planning a new welding project that is a first for me, and that demands respect because of loading requirements of the application.

The project is fabrication of a hydraulic press frame wih an active load of 30 tons. Although I am skeptical of using one of my 220 volt milier 180 amp millermatic welders for this project it sure would be covenient for me if I could.

So my question is - Is using a Mig welder for structural applications such as this press frame a fools errand ?

When welding I always grind or brush the weld areas clean, and grind for penetration as preparation.

[Cgotto6]

Mig is used in structural applications each and everyday. Many think stick is the only choice for load bearing weld mental which is just not true.

What thickness steel?

[knots43]

Mig is used in structural applications each and everyday. Many think stick is the only choice for load bearing weld mental which is just not true.

What thickness steel?

There are 1" thick elements that are to be welded to 1/4" thick tube. I figured a good preheat would be a compensation for the extra thicness. If so how much preheat is needed ?

[kize]

My Chinese made press that I inherited was made with mig. I don't for see any problems if done correctly.

[MMW]

My Chinese made press that I inherited was made with mig. I don't for see any problems if done correctly.

"if done correctly" is the key here.

knots43 -- I don't think you will get great penetration on 1" plate with your machine. I assume these welds will be in "shear"? No one here can tell you of your ability. I wouldn't trust it if it were mine. This is something that has the possibility of letting go violently under load with your head/body right next to it. Do you really want to be thinking about your welds every time you are maxing it out?

[aametalmaster]

So my question is - Is using a Mig welder for structural applications such as this press frame a fools errand ?

So how thick and what shape is your metal? I used my MM185 on my press and didn't have it maxed out...Bob

[knots43]

"if done correctly" is the key here.

knots43 -- I don't think you will get great penetration on 1" plate with your machine. I assume these welds will be in "shear"? No one here can tell you of your ability. I wouldn't trust it if it were mine. This is something that has the possibility of letting go violently under load with your head/body right next to it. Do you really want to be thinking about your welds every time you are maxing it out?

Yours is the obvious answer. Maybe with preheating it could work but the problem with preheating a sizeable frame is that it cannot be pre-heated all at once. Local pre-heats would likely cause distortion. I agree that without pre-heating the 1" plate that the results would be questionable at best.

For something this heavy about all I can rely on using the MIG would be tacking to get everything in alinement and set for the real welds.

Anybody ever use a toaster oven for a rod oven ?

[benweldingawhile]

Limitations for use of 180 Amp Mig Welder ???

No mention of metal transfer, could be short arced. But, spray would be better. Get a cylinder of 98/2 ( argon oxygen or argon CO2 ).

[MMW]

I don't know if the 180 has enough power to get into spray. There are ways to do this but the op has limited experience, limited machine & all he needs is to make a few welds for himself. My advice would be for him to tack it up & let someone with a larger machine weld it. No one here has even seen the design yet so saying it is o/k is irresponsible.

It may be fine forever but it only takes once when something lets go.

[benweldingawhile]

Limitations for use of 180 Amp Mig Welder ???

I believe 0.035 ER70S-6 wire will transition to spray at 24.5 + volts with a 90% + argon bi-mix shielding gas at 160 amps. May bump the duty cycle hard.

[Bistineau]

I am not new to welding however I am skeptical of using one of my 220 volt milier 180 amp millermatic welders for this project it sure would be covenient for me if I could.

Does this mean you have access to another welding machine besides the MM180? What other welding machine may you have available to use for this?