All MetalShaping

Go Back   All MetalShaping > General Metal Shaping Discussion > Welding Sheet Metal
  Today's Posts Posts for Last 7 Days Posts for Last 14 Days  

Thread Tools Search this Thread Display Modes
Old 06-02-2018, 02:12 AM
longyard longyard is offline
MetalShaper of the Month September 2013
Join Date: May 2012
Location: Winston-Salem, NC
Posts: 1,082

Cass Nawrocki says that if this issue happens with TIG welding, it can often be overcome by setting the amperage much higher than usual, but cutting the burst time significantly. He believes that in TIG welding, the issue is caused by "cooking" the metal and getting it to boil. Melting the metal should be the goal, not boiling it. He suggested to me a two-step pedal action. The first step is to melt the rod, but then move right on to a burst of pedal to melt the panel, but end this quickly. Cass has done many rosette welds with a TIG.
Bill Longyard
Winston-Salem, NC
Reply With Quote
Old 06-02-2018, 07:59 AM
Rick Mullin Rick Mullin is offline
Join Date: Mar 2012
Location: Malvern,PA
Posts: 88

I agree with Cass that you can over heat causing the puddle to percolate. Although I have experienced that, my experience with an occlusion that has erupted has been about oxide contamination.

In the certification courses that I have taken for aluminum MIG, ramp down, tailing off and allowing the gas post purge to complete is always a serious consideration. I realize aluminum is different than steel but I would think that the same rules would apply.

The new advances in welders, both MIG and TIG, when used to their potential have eliminated so many of the operator error issues making it much easier to produce a strong and attractive weld. I would like to think that I am a good welder but I have yet to out smart my new machine with all of it's software.
Reply With Quote
Old 06-03-2018, 07:50 AM
Kabous Kabous is offline
Join Date: Jun 2011
Location: Stellenbosch, South Africa
Posts: 71

I had the same problem with stick welding - if we are talking about the same thing - where the last second of welding ends up looking like a microscopic vulcano. I guess under magnification the cone-shaped arc means the rod is melted and sprayed in a circle thus creating an inner lack of material and leaving the pinhole.
I have solved this problem by 'smearing' the last half second of the weld finish across the face of the pool to fill up the hole.

Dont know if this might pertain to mig welding as well.
Reply With Quote
Old 06-28-2018, 07:34 PM
Oldnek Oldnek is offline
Join Date: Mar 2011
Location: Ulladulla, Australia
Posts: 1,344

I actually had this same problem today, welding brackets to a old diff housing.
After I welded and ground smooth there were craters, so I drilled those out and tried welding again, only to be in the same situation, so my issue appears to be contamination, from Diff oils and impregnated corrosion on the housing.
EK Holden V8
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 07:42 PM.

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.