Page 1 of 1
Stack of dimes... almost...
Posted: Fri Nov 16, 2018 7:07 pm
by ekbmuts
I'm doing some practice with some 1/4" 6061-T5 aluminum.
I'm using a PT185, set to 175 amps, AC, 72% penetration, 12CFH argon, no pulse.
I'm using a 1/8" red tungsten, sharpened and flattened off, with a 1/8" 4043 AL rod, gas lens and #8 pink cup. I'm brushing my aluminum and giving it a quick wipe with acetone.
I think the welds are sound and that I'm getting penetration but I'm not getting that classic stack of dimes look. The dimes are there but they're melted together somewhat. They're not distinct.
I'm jumping on my foot pedal to get started, moving relatively slowly and not massaging the weld puddle. But still, I'm not getting it.
Any suggestions would be appreciated.
Jon
L1020446.JPG
L1020445.JPG
L1020444.JPG
Re: Stack of dimes... almost...
Posted: Fri Nov 16, 2018 9:03 pm
by cj737
For 1/4”, you’re probably a bit low on heat actually. The distinct ripples come with distinct travel distance. Your beads appear to be more of a laywire filler add technique. Add more filler, then move a specific distance, like an 1/8”. Then pause, add filler, then move that distance again. Varying your travel distance effects the appearance of ally welds greatly. You also can play with your frequency to help with penetration a bit.
Re: Stack of dimes... almost...
Posted: Fri Nov 16, 2018 10:56 pm
by ekbmuts
cj, Yeah - sounds about right. My PT185 maxes out at exactly that: 185 amps and I do have a bit of a time getting the bead started and it feels like a lot of effort to keep it going. Sadly, I can't adjust frequency
with this machine and one day I'll invest in an inverter-based welder but right now this is what I've got.
Tracking on the pausing and then moving. I'll get my butt back in the chair and run some more beads...
Thanks again.
Jon
Re: Stack of dimes... almost...
Posted: Sat Nov 17, 2018 1:17 am
by trainingGrounds
The very bottom bead last picture has concavity. The easy fix for that is to add more filler wire as you go along. I agree with what cj737 says about it looking like a laywire technique. Be careful with that technique. You have to run it hot to get adequate fusion into the base plate. The filler wire cools the puddle if you have one at all in the base plates. So that's why the laywire technique has to be fast and hot to ensure fusion. While the laywire technique is easier to do it's actually more difficult to get complete fusion in my opinion. That's why the dimes method is what cj737 said. You are pausing and then moving because you are pausing for the purpose of fusing in the base plates.
Re: Stack of dimes... almost...
Posted: Sat Nov 17, 2018 6:55 am
by cj737
A decent training trick is to take a piece of flat stock. Scribe 2 parallel lines say 1/8"-3/16" wide (since you're using 1/8" filler). Then, mark across those lines every 1/8" (envision railroad tracks). Use these lines as bead guides. Add filler until the puddle is as wide as the rails, then step to each line to establish the puddle spacing. You will quickly see how much more filler you need to add than what your first pictures show.
Lots of filler!
Since your machine is restricted to 185 amps, both 1/4" material and 1/8" rod are too much material for your box. You could drop down to 3/32 filler and possibly get better results. But you can get better "dimes" with thicker filler as you're already adding lots more rod with each step.
Shove the filler into the middle of the puddle, slightly backing up or raising your torch. Wait until you see the puddle "grow/swell", remove the filler and move that specific distance, repeat. When you "slide" along with ally, you get those small, tight, ridge lines. But understand this:
The ridge lines are actually weak spots. The potential for cracking increases with those larger dimes
unless you have adequate filler and penetration. Those types of beads look beautiful on IG, but to get that result, those weldors have also established the heat, penetration, and arc control for strong
and beautiful welds. Start with strong welds, beauty will follow
Re: Stack of dimes... almost...
Posted: Sat Nov 17, 2018 10:00 pm
by ekbmuts
trainingGrounds & cj, Thanks for some great advice. I kinda had a feeling I was not adding enough filler even though it seems to me like I'm shoving it in there like there's no tomorrow! And I was also having trouble with 1/8" rod - I could not get a clean break with it. I'd shove it in the puddle and then when I pulled it out it would come out with a damn tail on it like I just cooled everything down too much. It all seemed so "sticky". So I'll stick with 3/32".
That drill with the lines is perfect. I'll probably grab some 1/8" AL (seeing as 1/4" really is a bit too much for my machine) and using a 3/32" tungsten and 3/32" rod, I'll go at it.
As far as the lay wire technique goes, I'll steer clear of it. I find that technique easy on mild steel and stainless (at least it's easIER) but with aluminum it seems that it takes a bit of mastering.
Really appreciate your feedback. Thanks a lot!
Jon
Re: Stack of dimes... almost...
Posted: Mon Nov 19, 2018 3:14 pm
by pgk
Here are a couple of Jodies video's showing what CJ was talking about, Jody looks like he ever so slightly move back and up while adding filler, Iv'e tried it and it does help me as my hands are not as steady as they once were. If you have any 1/8th setting around that would help you achieve better penetration, also you might want to try 2% Lanthanated too.
http://www.weldingtipsandtricks.com/alu ... lding.html
Re: Stack of dimes... almost...
Posted: Tue Nov 20, 2018 8:44 pm
by starvncoyote
I got a couple of wedlers that will pump the foot pedal as they move, it really looks nice and seems to be just as good as welding normally. depress while adding filler, let up the pedal and move forward. Also helps keep control of the heat input.
Re: Stack of dimes... almost...
Posted: Sat Nov 24, 2018 2:36 pm
by Warrenh
There are some guys in my shop that do that but it's not good technique and it's not necessary. Their welds never look as good as mine and I'm not convinced they are as strong. You need to see the pieces melt together in most joints and pumping the peddle doesn't make that happen consistently. It's a chest not a technique.
Sent from my moto g(6) (XT1925DL) using Tapatalk
Re: Stack of dimes... almost...
Posted: Sat Nov 24, 2018 2:37 pm
by Warrenh
I meant cheat.
Sent from my moto g(6) (XT1925DL) using Tapatalk