20 gauge welding test - ITMA

[elebub]

Kemppi MinarcMig 150
0.6mm wire
10 lpm Argon mix gas flow
20 gauge mild steel

As promised, pics of latest test piece.

Took onboard all the advice i.e. 0.6 wire, two hands on the gun and elbow resting on the bench, smaller gap between plates and a slower torch speed. Not exactly scar-like but I am pleased that there is hardly any distortion between the plates.

Your comments would be most welcome.

Andy

 

[Sparkey]

hi elebub! Still a bit too much power i guess... is that 1 mm steel?
I think you'd better not put your elbow on the bench either, just support your torch with the other hand or let it rest on your thumb or even hold the shroud(not too close to your work tho!!!) etc find out what makes you feel comfortable when you're welding, your body has to be at ease to!
keep up the good progress!!
Sparkey

 

[shenion]

Looks real good

You might try going bit faster once the weld gets going (notice not full penetration at start.) That should make the weld a bit thinner. Or cut the power a bit.

Looks better than the 0.6mm welds I did last week on 20GA steel. Doing about 20 feet of seam welds, I got sloppy at times. Was blowing holes at times. Kept lowering power (was well below 20A.) Finally upped the power and moved faster, was easier after getting the feel for it.

Is that argoshield light gas? Looks about right for that gas with welds a bit tall.

Does look like you have a nice machine there. You might play with the inductance (top left dial). It may get a flatter profile (but may also make blow-through more of an issue.)

 

[Sparkey]

hi shenion, now you're here... i don't have much experience with that thin material, do you suppose to have that much penetration?
Sparks

 

[elebub]

Thanks for the replies

Sparkey, its 0.9mm steel. I backed off the machines metal thickness knob (bottom right) to just under 1mm and these are the results. Interestingly there is more distortion now, presumably because there is less penetration with more weld on the top than the bottom.
For the next piece I will return the thickness setting to 1mm and do as Shenion suggests and play with the top left dial (inductance?) and increase the torch speed.

 

[malcolm]

It's a lot easier to start off with 1.5mm thick (if I've already mentioned that please forgive me). The margin between big globs (first photo) and too little penetration (last photo) is very small on the thin stuff and would be easier to achieve with a little practice on the thicker stuff.

Despite what has been said recently I favour a side to side action even on really thin metal. It keeps your speed constant, and also reduces the chances of straying off course.

With a side to side movement you'll be going at hobby welder speed so you'd need to set the dial to a much lower thickness.

Sparkey - the rules for thin are the same as rules for thick. Neither too much nor too little penetration be.

 

[shenion]

I prefer just a tiny bit out the back and the top about as thick as the metal. Hard to do consistently. The welds I did last week had very little coming out the back. As they were corner welds, as soon as it penetrated through, one of the sides would blow through. Also the gap was not that even at times. Add to that, I am using a 12' gun designed for 0.8-1.0mm wire so the 0.6 was a bit sloppy on the feed.

I did find vertical down a lot easier to control as it as less penetration.


Here's a quick weld I did while setting up the machine (still has some tweaking to do.) Done flat:

Still blew holes at ends You can see the thickness of the metal in the left of the bottom pic (the hole is 7mm wide). The top and bottom profile are about the same thickness as the metal. Top weld is about 4mm wide.

Was done with almost no weave, just moved from one side of seam to the other (probably about 2mm.)

If I could I would try to get even a thinner weld. Will take some more tweaking, the beast is designed for 200A+, not used to doing 20A As is, the weld is a bit taller than it should be. Probably should have used a bit more CO2 in the mix.

With my Clarke I could do welds that were real tiny and almost flat.

Heh, I just noticed my 0.6mm roll is almost gone. That stuff goes fast.

 

[elebub]

Still trying to get my head around what the two controls actually do in terms of wire speed and amperage. Will try weaving as you suggest Malcolm.

 

[malcolm]

I'm guessing you have the MiniarcMig Adaptive 150? Manual (pdf) isn't keen to give the game away.

Given that the only things you can control on a MIG are voltage and wire speed I'd be guessing that the knob with the steel thickness on it (which Kemppi describe as power) is the voltage setting (and that would also automatically adjust the wire speed to suit the new voltage setting) and the one with the pictures of fillet welds is a wire speed trimmer - turn it to the right to increase wire speed.

Fairly sensible arangement if that is the case. Though the actual numbers will probably be suited for professional welding speeds (faster than I can weld).

To be honest I'd assume the voltage scale is linear. Mark out 8 settings around the thickness knob. Find out what Kempii think the min and max amps for the welder are (20 min, 150 max would be a good starting point) and plug that info into the calculator, then mark it on the knob. Would probably be a better starting point for the likes of us.

The calculator suggests wire speed too - you could measure yours with a stopwatch and tape measure and mark that on the other dial.

 

[ngt]

Well i have the same problem with mma welding...
Starts with no penetration and a shortwhile the puddle sinks like a boat

 

[Lyhkaust]

You oughta try 'pulse welding' (what I like to call it). What you do, instead of making one solid weld, start at you left, or your right, whichever is more comfortable for you, pull the trigger ONCE while making an upside half moon shape, then let off your trigger. Then left your puddle cool a second, then fire it up again going the opposite direction in the same pattern. You're better off going in a pushing direction using the method I've just explained.

 

[mroek]

I'm guessing you have the MiniarcMig Adaptive 150? Manual (pdf) isn't keen to give the game away.

Given that the only things you can control on a MIG are voltage and wire speed I'd be guessing that the knob with the steel thickness on it (which Kemppi describe as power) is the voltage setting (and that would also automatically adjust the wire speed to suit the new voltage setting) and the one with the pictures of fillet welds is a wire speed trimmer - turn it to the right to increase wire speed.

Fairly sensible arangement if that is the case. Though the actual numbers will probably be suited for professional welding speeds (faster than I can weld).

The leftmost knob does not adjust wire speed, but voltage. If you turn the rightmost knob clockwise, you increase wire speed.

 

[elebub]

Thought I would email Kempii to get a definitive answer.

"Dear Sir,

Please note that the controls on the MinarcMig 150 alter 'power' (large
knob) and arc dynamics (Small knob) - wet fluid arc - or colder, more short
circuit arc."

Does something get lost in the translation from Finnish to English?

 

[ronnie l ventura]

hi,guys im beginer too, i tried welding joining 2mm metal sheet but i cant see the path ,it always wrong way [flat position].can you give advice , thanks

 

[elebub]

Small (and cheap) 12v 20w halogen desk lamp from IKEA was a great help. Bit of fettling and a couple of magnets and it can be used anywhere. You might have to up the wattage to 35 if you have a fixed shade (10) helmet.

 

[Sparkey]

yes, welding in a well lit workshop is much easier! (and it keeps your eyes from getting real tired too!) And as a plus you can mark the line you have to weld with a soapstone or crayon...Once you get more experienced you'll become familiar with what you see, the weldpool and the sparks that bounce of the joint so you'll see where you have to go!
A lot of practise, and your hands becoming steadier will help too!!
Hope this helps you out a bit! Sparkey