AC tig welding tungston splatter

By Bert Brown Date 05-25-2007 16:52

Hello -- This is my first post, so here goes. I have been having a tungston splatter problem when welding some aluminum castings on a friends Linde tig. I have a Lincoln 300/300 tig , and my machine is fine. The castings are about 3/16" thick and are cleaned with laqcuer thinner , I use a 1/8 pure tungston with a mix of 25% Hel/75% Arg. An associate told me that it could be the points need cleaning and adjusted, if so, where are the points and what dimension. I have been tig welding for many years and have never encountered this problem. Thanks for any advise, Bert

By Lawrence (*****)

Date 05-25-2007 16:59

Bert,

Welcome to the forum,

Forget the points, they have nothing to do with tungsten spatter. If the arc strikes when you hit the foot pedal and you are not observing rectification (very rough AC arc) than the points are dandy.

Sounds to me like the electrode is overheating

A water cooled torch will help.

A full length 3/32 or 1/8 Zirconium or Cerium electrode will help as they can carry much more current than a pure tungsten.

If you have balence control set it to 7 or 8 to keep more heat off of the tungsten.

Isopropol Alcohol or Acetone are preferable to thinner (less residue).

Try that and let us know what happens.

By Bert Brown Date 05-25-2007 17:10

Lawrence- Thanks for the tips. I do have a water cooled torch, but I do not use the zirconium tungstons. I will pick some up today and try it tonight. ( I do not want to work over the holidays). Thank you, I will let you know tomorrow. Bert

By Bert Brown Date 05-26-2007 18:42

Lawrence-- The welding store did not have any of the zirconium tungston in stock, so I welded the pieces with the pure tungston. I will get some zirconium for the next batch, which will be in about a month. Thanks, Bert