[usersony]

Hello, I've been having issues welding a small 1" OD (wall 0.085") Ai. bung onto a 2.5" OD (wall 0.075") Ai. pipe. I cannot get the two pieces of alumimum to puddle together. I can get puddles on either pieces, but I cannot get them to merge. I cleaned both pieces thoroughly. Stainless Steel brush and acetone wipe.
Here are my details:
Everlast PowerTig 185
CK TL 26 Flex with SuperFlex line
3/32 2% Lanthanated Tungsten, sharpened to a fine point
1/16 and 3/32 4043 Filler
100% Argon - 2 Bottles
12-20CFH Tried a few different flow rates
#8 pink cup
Stubby Gas lens kit from CK
SSC Controls Foot Pedal
Eastwood Welding Table

Here are my machine settings:
Set to AC and High Freq. Start and connected to 230v
Amps set to 100A currently. Have adjust to 80A and all the way to max 185A. Have foot pedal.
Frequency set at about 120hz to 200hz.
A/C Balance set at 50%. Have adjusted plenty either way
1/4" stickout up to half inch. Cup gets in the way
Sharpened tungsten 1/16" away from root.


The machine starts at 20A, I can see the cleaning action going but its tiny. So I give it more pedal, at around 50A the Ai starts to puddle on one side or the other, but never at the same time and never right at the root, If I point the tungsten to the other piece, the current puddle cools. I cannot get both pieces to puddle at the same time to join them with filler. I can get a blob of filler on each side and then get them to merge that way.

 

[Willie B]

If you puddle away from the joint your arc is too long. You got to get close. You must form your puddle in two seconds. Hit it hard! Once the puddles form, dab filler in the puddles. This part is tricky. You need enough heat in the puddles to melt filler, but it is very susceptible to keyholing. Once fused, move ahead. Heat until it is about to keyhole, dab.

 

[tweake]

3/32 2% Lanthanated Tungsten, sharpened to a fine point

don't sharpen to a fine point. sharpen it to a crayon tip.
the arc comes off the sides of the tungsten so a fine point makes the arc go wider. a blunt tip makes it more focused.
even if you can't start right in the joint, get it going on the sides, bridge it, then you can form a puddle in the centre and drive it down into the corner.

 

[Weld_]

Set your machine to the following.

120 A
Balance 70/30
Frequency around 80
20 chf on the gas.

 

[shovelon]

Start your arc and when you see the two halves melting cram the rod in to bridge the two. Once bridged add rod as usual and if one side flows away too much cram the rod into it to catch it then carry on. Sometimes feathering you pedal can help prevent one side melting away also.

 

[DHFG]

and if one side flows away too much cram the rod into it to catch it then carry on.

Can you clarify what is happening here. Are you cooling the puddle to slow it down?

Thanks

 

[motolife313]

Aluminum takes a lot of amps

 

[TJS]

Stop hanging around with the low amp stuff. Hammer the pedal, you should get a puddle in less than three seconds. Then back off if it seems as you may blow a hole. Listen to Shovelton, this will work.

 

[Oscar]

120Hz should be fine, unless the included angle is acute (<90°). Long taper 2-3x diameter, tiny blunt tip, and yes, stop hanging around with the low-amp stuff. Why do you have the balance at 50%? CLEAN that aluminum properly and crank up the balance to 75-80% EN (equivalently: 20-25% EP) and blast it quickly (IOW: split second) with about 130A to get a good tack. Have the filler ready to jam in in there. But of course don't practice on the actual part. Get some mock-up pieces to dial everything in (hopefully that is not too late). As was said, have to get in there close to make them bridge together, assuming they are actually touching and you don't have a gap! No more than 2mm! 1mm would be even better, if your hand is steady enough. And get ready to lift the torch just slightly when you add the filler as the puddle will plump up as soon as you add filler! It's tricky, but obviously it can be done. "The machine starts at 20A,", this is the main problem to be honest. Assuming you don't even need the cleaning action, just get the tacks going with a quick hi-amp blast. If you have a spot timer now would be the time to learn how to use it if you feel so inclined, but you really need to blast them quickly unless you absolutely need to hang around 1/2 a day slowly ramping up from 20A, lol.

 

[Oscar]

I'm not saying do exactly this, but if you set things right, you can achieve quick, autogenous tacks if you get the "pulse" just-right (along with all the other parameters/technique). Of course you want the pulse to be long enough for you to sneak the filler in there, but I've done this using an on-off switch on my TIG torch on some 0.062" aluminum outside corner, and it works great when you set everything right. High AC frequency helps to narrow the arc cone, as does high EN% (ie: low EP%) to a certain extent.


(first 48 seconds of this video)..

[video=youtube_share;JIVJpDUl8FM]https://youtu.be/JIVJpDUl8FM[/video]

 

[shovelon]

Can you clarify what is happening here. Are you cooling the puddle to slow it down?

Thanks

Sometimes a thinner member will melt faster than a thicker member. When it does concentrate your arc more on the thicker member slightly and cram rod in to catch the thinner member meltback. Or a lap weld will melt the top layer faster than the bottom member. Seeing as it does again modify your torch angle, pull the torch more to the bottom layer and cram the rod in to catch the upper member.

 

[Jawslandshark]

Maybe practice at aluminum and get proficient at it rather than jumping right into welding a part? I get people bringing me stuff that they worked hours on only to cobble it up because they thought just because they had a tig welder they could weld aluminum. I usually hear that they watched YouTube videos on how to do it, that's a great idea if you want to make brownies. Usually takes me longer to clean it up and get it back to normal then actually weld. I am all for helping people but you have to put in the seat time and gain the knowledge, trial and error, master the technique and don't be afraid of hammering the pedal.

 

[Oscar]

that's a great idea if you want to make brownies.

:laugh:

 

[usersony]

I've upload a photo so that it shows exactly what the joing looks like and how close I get to the root. Thank you all for you help and comments! I appreciate the help!

edit: for some reason the photo came out 90 degrees rotated. And when I spark up I get closer that what it looks like in the photo.

 

[usersony]

Thank you for the settings, will give it a go!

 

[usersony]

If you puddle away from the joint your arc is too long. You got to get close. You must form your puddle in two seconds. Hit it hard! Once the puddles form, dab filler in the puddles. This part is tricky. You need enough heat in the puddles to melt filler, but it is very susceptible to keyholing. Once fused, move ahead. Heat until it is about to keyhole, dab.

Thank you, will definitely hit it hard when I try again! Aluminum is such a finicky ^@%$^$@

 

[usersony]

Maybe practice at aluminum and get proficient at it rather than jumping right into welding a part? I get people bringing me stuff that they worked hours on only to cobble it up because they thought just because they had a tig welder they could weld aluminum. I usually hear that they watched YouTube videos on how to do it, that's a great idea if you want to make brownies. Usually takes me longer to clean it up and get it back to normal then actually weld. I am all for helping people but you have to put in the seat time and gain the knowledge, trial and error, master the technique and don't be afraid of hammering the pedal.

Yes you are right about not being proficient at all. I am trying and trying hard. I bought plenty of practice material, and have at least 5 to 6 hrs already in seat time on this specific project. On the other hand I did manage to join 2 pieces of intercooler piping together with a nice bead all the way around. Thank you for your input and I will definitely hammer the pedal.

 

[usersony]

Thank you for the tips and technique! I did get plenty of practice/mock-up materials so that is what I have been practicing on. I will definitely try your way, I have been afraid to blast from the start. I appreciate your time.

 

[Kevin Morin]

usersony,
my remark is about my description of starting the arc and getting a puddle to weld TIG aluminum. I agree with the basic idea of 'blast it' or 'full pedal' as the spirit of the method to get enough heat into the part- at the weld zone- to melt the parent metals' edges.

But I'd describe it slightly differently- because the event seems to me better described by saying " as soon as your start the arc/contactor in your power supply- begin adding amperage- rapidly- so you'd end up with a full pedal IF you got that far?"

There are several cases of power supply settings involved - and I think they have to be taken into account when discussing arc/puddle forming with the newer/low hour TIG welder?

The pedal, knob, slider or TIG Button all represent a % of the MAX output as dialed into the power supply. So; if you're MAX output is 300 A ( or 200A?) and your power supply is set to that MAX : THEN the fully depressed pedal or slider is the full 100% output of the setting or 300 A (or 200 A as the power supply is set to limits?)


IN THAt case I'd say that "full pedal" might be too much? as the MAX output may be too much amperage for the planned weld to accept without dropping out or melting through?

That is the case where I'd describe the starting process of "ramping up the amperage rapidly" - but.... as soon as arc foot print on the parent metal gets liquid and shiny?? SToP!! and back off a small amount, add filler and get going.

However, there is another entire method of setting the MAX output to 're-range' the pedal or sliders' control range. By lowering the MAX output of a 300 A power supply to 220A or 100A, as examples; the pedal or slider only provides a low to highest percentage of ThaT value.

so in this second case; the full pedal may well be exactly what is needed to get a puddle going- as in this 2nd case; the MAX output of the power supply is limited to the lower amperage's suggested above.

The gain to using this method is really set up by practice plates. Clamp the parts adjacent to one another -clean and prep both parent metal and filler metal rod- make sure there is an adequate pre-flow so the arc initiates under a gas shield and start the arc and push the pedal all the way "to the floor". Count to three- two count is often enough time? IF the puddle has not wetted out in that time- stop the weld/tack.

Now add some amperage to the MAX output setting of the power supply- say 20 A? And repeat this until the 'full pedal' move causes a wetted out puddle to form.

Now, every time you initiate an arc - for those particular size pieces in that weld position- you'll get a wetted out puddle in a short time by simply flooring the pedal.

In the first case- once you've welded aluminum TIG for a while your pedal movements (at full MAX output) will stop - you'll see the wetting out begin and your reflexes will stop your pedal foot from adding more amperage. However, until you get to that state of recognizing the puddle forming at its initial stages, you can go through the exercise to set the MAX output (just high enough) and then make use of a 'full pedal' move to get started.

Hope this come across in words? I hope it helps you consider exploring both methods- to reduce your frustration as you get your hand-eye awareness of aluminum puddle appearances more refined.

Cheers,
Kevin Morin
Kenai, AK

 

[usersony]

Kevin, thank you a bunch for your informative post and willingness to help. I finally got a couple homogenous tacks on the pieces I was working on. I also read this reply of yours about arc shift based on distance, which also helped me tremendously http://www.glen-l.com/phpBB2/viewtopic.php?f=7&t=28367&start=30 . Thank you once again, and thank you to everyone else that took time to give me pointers.