Stack of dimes?

[illuzion]

I'm starting to play with the TIG a little more for all my light fabrication work (I shelved the wirefed just so I can get some good practice), now I can make a very nice looking "bead" with tig, but I cannot seem to get that stack of dimes or stack of nickels looking weld. How do I achieve that effect? Can it only be done with a pulser, or will a steady arc do it too? And also to get that effect is the torch motion straight or is it a continuious circular motion?? Probably silly questions, but for someone that lacks the tig experience, I found that a few silly questions saves a lot of headache.
Thanks in Advance
-illuzion

PS - Keep an eye out for Horror Story Pt II (was re: decisions), coming soon to a message board near you

[cope]

I don't Tig, but IMHO, the stack of dimes look is way over-rated as a requirement for any welding technique; the main thing you need to do is master basic welding techniques and be sure that your welds are sound. Once that has been accomplished you can start worrying about the look. Excellent quality welds mayy exhibit the stack look, but poor welds with cold fusion may also look that way.

[HAWK]

illuzion,

Glad to hear your TIG is coming along nicely. Pulsing is one way to achieve the stacked dimes, but it also takes considerable hand/eye coordination and practice. Here is how to do it with your machine without the pulser. Set the amperage for your aluminum thickness, (I guess you are working with aluminum), arc frequency at 135HZ, EN balance 75%. Clean your base metal and filler with Scotch Brite and wipe with acetone.

Strike your arc using the HF amptrol and circle the torch counterclockwise just above the begininning point until your base metal puddles good. Add a dab of filler rod, be careful not to hit your tungsten with the filler, then advance your torch forward and continue this CCW motion until the filler puddles good and the weld toes are washed in good, add filler and advance the torch again. Continue this action to form your weld bead. I try to keep the torch moving and continually add filler as needed. You can also back the torch up, add filler, bring the torch forward again, and repeat. This works well, but the bead is not as pretty.

This procedure is for right handed welding from right to left. For left hand welding travel from left to right circle clockwise and advance as described above. Do not run you torch in a straight line without circling. This only causes lack of fusion due to lack of heat input over the weld area.

[Paul Seaman]

Hawk that is the easiest descriprion I have seen for Tig anything. The hardest part is the eye, hand coordination. I've only messed with tig a few times and knew it would be a long road, so I've moved on to practice and build skill on other things. Think I might have to give this another try. Thanks for all the help, by the way my computer is DOA I'll email you when I get the replacement. Thanks again.

[illuzion]

Right now I use a left handed torch technique, with filler rod in right hand, I make clockwise circles, and add filler rod, and I usually end up with a nice *continuious* bead, similar to something you would see with Fluxcored wire fed. I can't seem to figure out how to get that "stack of dimes" effect. I usually (95% of the time) work with mild steel. I haven't had too much opportunity to practice with alum yet (although the few times I tried it was not bad). I think the technique has something to do with the filler rod, I think I am adding the filler too slowly and continuously, as opposed to adding a large amount of filler for a short period of time and then advancing the torch, and repeating, and actually "pulsing" the filler into the weld, as I saw someone doing in a video to achieve that "stacked" effect.
Thanks
illuzion

[HAWK]

illuzion,

Keep up the good work! Let's try to get you stacking your beads. Make a deliberate circle "C" motion with you torch each time you add filler. Slow down and take time. Watch the rod flow and puddle out to wash the toes, then circle the torch and add filler again.

If memory serves me correct, you have the D200DX. Set the pulser for 1.5PPS, 50% peak time, 30% background amperage. Each time the pulse goes high (arc brightens and puddle widens a bit) add your filler. This takes some practice to coordinate the hand and eye. Once you get this you will have your stacked beads. You can certainly stack them with out pulsing, but this will help teach you the technique. You may want to play with the pulse rate to see what suits your liking. Adjust it from .8 up to 2.0 PPS. When you start cranking the pulse rate up to say 200PPS you will only add to the smoothness of the bead. You will also begin shaking the puddle and agitating the base material impurities causing them to float to the top of the puddle.

Walking the cup is another style you may want to familiarize yourself with. Once you bead is started rest the torch cup against the newly formed bead just behind your puddle. Keep your tungsten stickout from the cup short when walking the cup: somewhere between flush and the diameter of the tungsten (3/32")if you are using 3/32" tungsten.

[illuzion]

HAWK,
Thanks for all the great advice. Yes I do have a D200DX (and almost a spectrum 625 - more on that later), Now I understand why the pulsing teaches you the correct technique for a stacked weld, it has to do with the pulsed filler addition. I have to admit, I have not tried the pulsing feature yet (haven't had the need yet, everything I tigged was heavy enough that I wouldn't blow though, and if it seemed to be getting too hot, I back down on the amptrol (finger). I have never heard of "walking the cup" but I will try it, how exactly does it work? And it does not contaminate the weld? I assume, it is certainly a cooling issue, as the cup touches the puddle, it causes it to freeze in the shape of the cup edge? And if you make these indentations in the weld repeatedly, it gives the "stacked" effect?
Thanks
illuzion

[HAWK]

illuzion,

The cup touches the solidified weld metal. The puddle has already cooled enough to be solid. Resting the cup only gives you a place to be steady. You are really just rocking the cup back and forth against the weld bead you have already put down as you are moving forward. It has nothing to do with weld contamination or shape as far as the cup touching the welding. The bead shape is altered by the rocking motion of the cup as you move forward. Walking the cup is really more applicable to pipe welding where you have a groove or bevel joint. Don't worry to much about it with plate. I just threw it out as something else to try. It is easiet to do than it is to explain. What is up with the plasma cutter???

[illuzion]

Here is one of my early attempts at stacking on mild steel, this was a few weeks ago. I have gotten a little better since then, but haven't had much of a chance to take pics lately.
-illuzion

[HAWK]

illuzion,

Nice attempt. Where is your balance set? When properly set you will see a lighter area all around the weld bead perimeter. This is an indication of the cleaning action. Time spent welding will help you as much as anything. The proper technique is important also.

[illuzion]

I thought balance/cleaning only applied to AC Tig, this was a DC Weld (mild steel). In my case, I'm sure practice will prevail. I just need time to sit and play with it. I'm trying to perfect working with steel before I really start with alum. I have run a few beads with AC on aluminum just to see how the machine performs, 80/20 Balance, 150hz, 3/32 2% Thoriated, 15CFH Argon, 4043 Filler, not a bad result at all with no preheating.
-illuzion

[HAWK]

illuzion,

My fault. You are correct. It looks a lot like aluminum. I think it is the way the light is shining.

[illuzion]

I'm not 100% sure, but I think I tend to be a little heavy on the amperage, as the weld is really penetrated into the metal, if you study it, it almost borders on undercutting around the edges of the weld, not sure if this is a bad thing or not, but I have seen much nicer looking TIG welds that look much more on the surface than mine.
-illuzion

[HAWK]

illuzion,

I think you are too hot and maybe trying to push in too much filler. Keep practicing and good luck.

[ASKANDY]

Guys,
There are many ways to get the"dimes". And I realize that how people master that technique will vary but you can easily get the stacked look without any type of torch circles or "C" movements. The only time I use these methods is when I'm doing heavy weldments and I need to swirl the torch to get the toes to tie in. Otherwise just dab and move...dab and move. Most of my students when they start out, tend to add too much filler and not move the torch over far enough along the joint. The result is a bead that is higher and has too much filler overlap that all you did was stack your dimes too close. I cut some 1/8" Alum into 6" strips and welded them up with 3 different spacing. Keep in mind that the wider the spacing, the more chance of crater cracking or toe cracks because you do not have sufficient overlap to cover the crater of each bead. You see alot of these wide bead placements in racing seats or things that do not need to be structurally sound. Yea they look neat but in reality they are a bad weld. These seats will never break as there is so much material deposition around the whole seat. However, if this were a smaller critical weldment under stress, I could easily see a failure.

I did all these welds in about 3 minutes total and cover Butt, outside corner and fillet. Each sample has normal spacing, tighter spacing and wide spaced beads. No torch movements except forward. These were all done on Aluminum which is generally harder to do than steel but the same technique is done for steel.

I would try to master the dab and move method before trying to swirl or walk the cup. These will come later as you get comfortable with your torch and filler coordination.

Please see the following pics on the next page.
Keep in mind that these were done quickly and I'm no photographer

Hope this helps. If you need additional pics, let me know and I'll try to do some.

Andy