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Thin sheet metal (Beginner question)
Posted: Mon Apr 11, 2022 11:37 pm
by Cross_22
After coming to terms with 1/8", 1/4" and 1/2" steel, I went in the other direction and tried to join some 26ga sheet metal (1018). Not much luck with that. The only thing that worked out consistently was spot welding by sandwiching two pieces, setting max amps to 45 and flooring the pedal for 1 second.
With butt and filet joints I could not get the pieces to tack - it goes from cold to burn through in a split second. My setup was a 1/16" electrode and 10A max. Any suggestions on what I could try?
Re: Thin sheet metal (Beginner question)
Posted: Tue Apr 12, 2022 1:21 am
by tweake
chill blocks and perfect fit up. insanely close arc length.
the other trick which can look horrible is to use filler and light up on the filler.
also a spot timer can help or use pulse.
Re: Thin sheet metal (Beginner question)
Posted: Tue Apr 12, 2022 8:20 am
by cj737
tweake wrote: ↑Tue Apr 12, 2022 1:21 am
Insanely close arc length.
^^^ This.
With thicker material you can get away with a longer arc as is there is more mass to tolerate the added heat from the arc. But with super thin material, you have inadequate control of the arc if you are too long. Nearly touching it is the proper distance. And you might use a backer/chill block to hold the joint in a truly touching configuration. Any gap will very likely blow out, no matter who you are or how long you’ve been welding.
Re: Thin sheet metal (Beginner question)
Posted: Wed Apr 13, 2022 12:58 pm
by Cross_22
Thank you very much.
I tried pulsing, but minimum base current was still too high. Chill blocks were in place. I am going to blame poor fit up as the most likely culprit.
Re: Thin sheet metal (Beginner question)
Posted: Wed Apr 13, 2022 11:55 pm
by cj737
I am not a fan of pulse for tacking. Easier to use straight amperage with a pedal or switch in my experience.
Re: Thin sheet metal (Beginner question)
Posted: Thu Apr 14, 2022 8:40 pm
by tweake
cj737 wrote: ↑Wed Apr 13, 2022 11:55 pm
I am not a fan of pulse for tacking. Easier to use straight amperage with a pedal or switch in my experience.
you can use extremely low pulse to act as a kind of spot timer, ie it turns off more accurately than you can. its a hack but can work.
the other way is to use high pulse to make it run cooler. as many affordable welders do not do low amps very well, its a way to get a cooler arc at higher amps.
that also can mean the pedal will have more usable range in it. thats something i do quite often for thin material.