Drag Cup Tig Welding

[moellerswelding]

Does anyone know the procedure for Drag Cup Tig welding?

[fun4now]

are you refering to "walking-the-cup" ?

[aphexafx]

Yeah...like, do you mean keeping the cup in contact with the work in order to maintain your arc length?

[OldSparks]

moellerswelding

I think the term ‘drag cup’ applies more to plasma cutting. If it’s ‘walking the cup’ you’re after, below is a link with a few pictures. I don't use it myself but have seen it a few times. I'm surprised more novices don't start out with this technique. A few generalizations. It's meant for mild, low-alloy and stainless steels (I doubt aluminum). Fit-up is critical with any material over 3/32" bevelled to a point (no land). Material should be tacked with a gap such that a 1/8 filler rod will not pass through. Use a thin wedge when tacking to keep your gap consistent. Because of the open gap and no land there is no need to constantly manipulate filler and torch to keyhole and add metal for a full penetration root. The filler is bent so it will lay evenly in the groove.
'Walking the cup' refers to keeping the edge of your cup in contact with the base metal. By twisting your wrist you advance slightly along the root while directing the arc to alternate sides of the filler rod. Amperage and speed can vary with metal thickness. You just want to see the rod flatten out as you pass over it. This is where experience will tell you when your root will be o.k. but once learned this maneuver can be very consistent. Less chance of fouling tungsten and excellent gas coverage. Additional passes would involve changing cup to a larger diameter opening which in effect would keep your tungsten back for proper arc length.
As shown in the pics, a very nice cap can be put on. A faster filler rate would be needed then for root and second pass. You have to practice feeding the edges as you advance.

http://www.weldinginspectionsvcs.com/WalkingTheCup.htm#freehanding

Below is a copy/paste from a different article. I did this freehand but the pictures and amperages should still apply.

I've tried to throw together a little demo. The pictures show 3/16th plate with a gap just tight enough that a 1/8th rod won't fall through. Done on the flat. Numbers are amp settings I experimented at. Probably recommend 95 or so depending on how much the plate heats up on you. Lay your rod in the groove and strike your arc. Keep your torch in motion, a few slow weaves across the end of the rod from edge to edge and you'll see it flatten as it melts. Now continue weaving along your rod at a speed that is just fast enough to keep the rod flattening out. With a proper fit up you shouldn't have to worry about intentionally keyholing but you are bound to blow through as you learn the proper travel speed. When that happens, momentarily aim your torch a little higher up one of the bevelled edges while you move your rod closer to butt it up with the existing root.

http://www.hobartwelders.com/mboard/attachment.php?attachmentid=7806

http://www.hobartwelders.com/mboard/attachment.php?attachmentid=7804

http://www.hobartwelders.com/mboard/attachment.php?attachmentid=7805

[ASKANDY]

Welcome OldSparks!!

I liked your explanation of walking the cup. I really didn't master it until I had to do a bunch of SS headers for race engines. It was a little difficult at first but like anything, I cought on after a bit of practice.

Thanks for the input.
see you soon

Andy

[rb455ho]

Oldsparks, great info. Thanks and welcome aboard.

[T0M]

sorry to bring up an old thread guys but I am trying to learn this walking the cup method. most of the information I find refers to thicker material(suck as the link above). I am trying to learn this specifically for welding 16 gauge stainless. does anyone know of any other informative links on this subject?

[HAWK]

TOM,

Walking the cup works great for tigging pipe. Take a look at this link in the Miller TIG Handbook. There is some information as well as a picture on page 65.