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Quick "T" joint question

Posted: Thu Nov 14, 2013 9:09 am
by sgtnoah
Just a quick question if you folks have a minute.

Been working on T joints with aluminum. Using 1" x 1/8" strips of 6061, 3/32" 4043 filler, 3/32" 1.5% Lanth Tungsten (sharpened, point rounded to a small ball), 100hz, 75 balance. Running the torch as close as I dare to the puddle, and contaminating a tungsten once in a while, so thinking that I must be keeping a tight arc :). Trying to think of other relevant details...

When I lay down just a bead, it looks nice, shiny, good cleaning action and gas coverage. It's when I do the T welds that the problems happen, having a hard time penetrating into the corner, if I give it enough amps to wash into the corner, it overheats the material on the legs (filler like water, grainy weld, ripples washed out - not distinct, pretty much all the "you are welding too hot" clues. If I lower the amperage, I can get a decent weld on the legs, but it doesn't drop down into the root. Also when I lower the amperage the arc wants to favor one leg or the other, hard to keep equal heat on both of the legs. Running a straight forward and backward motion, keeping the point aimed right at the root.

Thank you in advance for your thoughts, this site is such a wonderful resource!

-- Pete

Re: Quick "T" joint question

Posted: Thu Nov 14, 2013 3:22 pm
by weldin mike 27
Maybe try adjusting the ac balance towards the penetration side. To focus the arc and get it to punch into the corner. Not sure though . Not an AL guy.

Mick

Re: Quick "T" joint question

Posted: Thu Nov 14, 2013 5:01 pm
by ajlskater1
A few tip that may help. The first tip is to try the technique jody uses it works extremely well for fillet welds another tip is try turning ac balance, filley do not require as much cleaning action because yhe area you are welding us concentrated, on that sane note yoy can also turn your gas flow down slightly. Another little side note 4043 because it flows so nice it kinda a negative when doing fillet welds, 5356 tends to lok nice. One lwst tip is sometimes you have to wait a little bit to let you puddle flow down into the joint, this will help you with 4043 and making it look nicer by letting yoy not use more amps and getting that grainy look

Re: Quick "T" joint question

Posted: Thu Nov 14, 2013 7:40 pm
by Otto Nobedder
Pete, what I've found works for me, is to take smaller steps, and move my tungsten in and out.

What I mean is, once I have a puddle tying both legs, I advance about half as far as I would for a flat 1g weld, and move the tungsten in tight, until I see the puddle tie the legs together at the arc. I then feed rod, while drawing the tungsten back to avoid contact, then advance that tiny bit again... Using a foot-pedal is a help here, as I can "up" the amps as I pull back and dip. Getting the full tie-in you're looking for takes patience. You have to wait on the puddle to advance to where you want it before you dip and pull out.

This is damn hard to put in to words. I wish I had a way to "show" what I mean.

Steve S

Re: Quick "T" joint question

Posted: Fri Nov 15, 2013 7:59 am
by sgtnoah
Thanks for the advice, looks like it's a good time for the weekend to start so there is time to practice these new ideas!
Hope you fellas have a good weekend.
-- Pete

Re: Quick "T" joint question

Posted: Fri Nov 15, 2013 8:33 am
by MinnesotaDave
This vid shows a little of what Steve S. is saying.
http://welding-tv.com/2012/04/19/alumin ... p-and-tee/

You say the metal overheats when you give it enough amps. You prob are not giving the amps fast enough then.

That puddle needs to form in 3 seconds or less or you are too slow and saturating the piece with heat.

Oh, and one inch strips are very small, tend to saturate quickly. Make sure they are long enough to give you some "meat" or you are fighting that as well.

Re: Quick "T" joint question

Posted: Sat Nov 16, 2013 4:15 pm
by Otto Nobedder
Thanks, Dave,

That video does show and explain pretty well what I was trying to say. It is clear in the arc shot that he doesn't add filler until the puddle advances, and you can see him draw back while dipping. The explanation is spot-on as well. I still occasionally have the tungsten and puddle "meet" while feeding, because that aluminum expands so much with heat...

Steve S

Re: Quick "T" joint question

Posted: Sun Nov 17, 2013 9:21 pm
by Nils
Pete,

I know exactly what you're asking here. I have encountered the same thing many times. I am a newbie alum/tig welder too. Many of Jodie's videos, as the one referenced, do not show the very beginning process on this type of joint. Omitting the start of a fillet weld on a alum tutorial is a big swing and a miss. I think the best advice given here was about you possibly not using enough amps on the front end of the weld. This will delay laying the bead as you try to get a puddle going, but will saturate the work with unwanted heat. Also, working with a larger piece of aluminum will help the heat situation.

I have the utmost regard and respect for Jodie and mean no disrespect for any of his fine work and contribution to the welding profession. I personally have benefitted beyond description by his long list of welding tutorial videos and always look forward to his new releases. Jodie is a welding god.