I have typically seen fabricators use DCEP polarity for all SAW processes in the shop - granted my experience is limited to bridge fabrication.

Do most fabricators use DCEP polarity for SAW process?

I have recently come across a fabricator that wants to use DCEN polarity for a dart welding process that is fillet welding both sides of T joint simultaneously.  An example of this would be to use a Dart welder to fillet weld a stiffener to a girder web along both faces of the stiffener simultaneously.

My understanding is that DCEN results in less penetration which would be beneficial in controlling undercracking in a dual electrode process such is that described above.  However, Lincoln Electric does not recommend DCEN for use in SAW, and LE's certificate of conformance is run with DCEP.

What polarity have others seen used with SAW?

Thanks.