Welding Tips and Tricks

I have seen many videos where the weld looks like "stacked dimes" but mine seem to be the correct height and width but smooth. Lincoln Square Wave 200, 1/8" mild steel, 3/38 Lazr tungsten, 120 amps, 1pps. Ideas?

bulletbusiness wrote: ↑Fri Aug 18, 2023 4:35 pm I have seen many videos where the weld looks like "stacked dimes" but mine seem to be the correct height and width but smooth. Lincoln Square Wave 200, 1/8" mild steel, 3/38 Lazr tungsten, 120 amps, 1pps. Ideas?

No doubt with a key word of "dimes", there will be other posts. It's one of those favorite subjects.

To get "dimes", the puddle has to (at least partially) freeze. That can be achieved with torch movement and with the addition of filler. A larger filler will cool the puddle more and a "dab and step" movement will leave the required lumps.

What filler are you using? Usually no filler = no dimes.

Dimes are not a requirement for a successful TIG weld but are often a side effect of adding filler.

You are using quite a small tungsten.

Jack

sorry - 03/32 tungsten. I've tried several different sizes of filler (70-2) . Haven't quite figured out how to add a photo, but will eventually. TIA

3/32 tungsten is perfectly fine for welding 1/8” steel. I would suspect the travel speed is the culprit for your “smooth” beads.

As Jack said, add enough filler while you pause your torch movement until the bead get to the proper width then move and pause again. The slight pause is what creates the chill zones (dimes) when you move.

Not sure if the attachment went but this is what I'm looking at. Piece of 1/8" DOM scrap

The bottom bead shows too long of a torch movement between pauses.
The middle bead is better.
The top bead reflects heat-soaked base metal and thus your beads are not using sufficient filler to create a chilled puddle.

You can quench mild steel between practice beads to cool the metal down without issue. Don’t do it to production products though.

I appreciate the help! I do on occasion quench the coupons between passes but sometimes think...."just one more", I'll throttle back the pedal a bit. Am currently using a Lincoln Squarewave 200 but have been looking at the primeweld 225. Am I crazy?

is it possible I'm dragging my tungsten in the pool?

What else would cause the stripe, it's in several of my beads.

Torch angle and too fast a travel speed. What grind angle do you have on your tungsten?

Torch angle too shallow or too steep? Here's the tungsten grind, I'm guessing 15 degrees. I have noticed that the course wheel I'm grinding it on isn't nearly as nice of finish as the diamond grinder. Does it matter?

I would say torch angle to shallow, like you’re pointing ahead. You want as close to 90* whenever possible which normally results in about a 15* lean in one direction.

Your grind angle is fine, and the only thing that polished grind ensures is a clean, crisp start and no wandering arc. For practice, you’re fine.

Make sure you NEVER snap the tungsten to length. Always grind them in half then sharpen the ends. Snapping them causes micro fractures or worse.

I'll work on it. Thx for your help!