Welding burps

[Steeler]

New to the forum, please pardon my inexperience. I use a Millermatic 135 (115V) MIG for doing very light sculptural work with very thin steel sheet and steel rods. I'm using .023 wire with a CO2/Argon mix gas. I seem to have the amp/wire setting dialed in well...BUT...

Every so often a weld will sort of "burp"-- like a gas pocket gets trapped inside the weld and then a finger or metal bubble erupts out of the weld. I can pry the protrusion off with needle nosed pliers and see a vacant opening inside where gas or air was trapped. Any advice or remedy to this would be appreciated.

This problem never seems to happen in early welds-- it seems to happen after 20-30 minutes of continuous work.

Thanks--

[landman]

sounds like your not getting good gas flow. If your outside that would be your problem

[sn0border88]

It can also be from contamination on the base metal. Once its trapped in the hot weld metal it will burn and release gases which cause the bubbles you see. Make sure your removing mill scale, dirt, grease and paint before welding.

[DesertRider33]

Torch angle can cause it too. If you're laying the torch down too much the gas doesn't cover the weld like it's supposed to.