Welding Tips and Tricks

Hello all,

I'm working on a small personal project - an aluminum frame to hold some Christmas lights (the outline of a star). I'm trying to figure out how to TIG some .062 wall aluminum tube (5/16 diameter) to a small piece of .128 plate. All of the material is 6061 and I have 4043 filler wire.

I'm struggling to join these dissimilar thicknesses. Right about the time I get a nice puddle on the .128 plate the tube collapses into a blob and breaks off.

I have at my disposal a Miller Multimatic 220, 3/32" tungsten, 3/32" filler, and 100% argon. What I don't have is training - I'm a hobbyist and just trying to figure things out as I go.

I've attached a couple pictures of one of the joints I'm trying to form. I don't need anything to flow through the tubes - it's just the material I had available to make the frame. Note in the pictures that I haven't cleaned the material. In my tests I have.

Thoughts/guidance is appreciated.

Thanks,

j

Sounds like a frequency, and a amp issue. There’s a fine line between breaking down the oxide and melting the aluminum. If your trying to creep up on it then your fighting your self. Aluminum reacts much different than steel. You need to get at it quick, to get it to melt.

150 amps. Yes 150. Focus your arc (and keep it tight ti the plate) and get your puddle. Then add filler and wick over to the tube edge. Add more filler. You will want about 4 dabs at the end of each tube against the plate. Stop after each one, re-orient yourself, and go again.

Once you have your first one done, you can back off the amps using the pedal as you won't need as much amperage for the successive tubes since the plate is hot. The plate needs to get hot quickly.

cj737 wrote:150 amps. Yes 150. Focus your arc (and keep it tight ti the plate) and get your puddle. Then add filler and wick over to the tube edge. Add more filler. You will want about 4 dabs at the end of each tube against the plate. Stop after each one, re-orient yourself, and go again.

Once you have your first one done, you can back off the amps using the pedal as you won't need as much amperage for the successive tubes since the plate is hot. The plate needs to get hot quickly.

+1

also i would tack in the centre at the end of the tube and at the outer edge of the plate.
both places should easier to weld than along the length of the tube. once its tacked in place it will be easier to weld down the length.

Thick with thin, does up the challenge some.
The main thing to keep in mind, is the heat is greatest where you point the torch. Aim it more directly at the thicker material. Once it gets that glassy look, then bump the torch towards the tubing for a second. Back towards the thicker material as you dab filler. Start where the outer edge of the disk meets the tube. Then weld where the tubes meet. The hardest area to weld, is the crevice along where the tube lays against the disk. Very difficult to control where the heat is going . It can be done, but not a good place for a beginner.

Edit,
Tweak beat me to it.

Wow! Thank you all for the advice. I'm going to give it another try in the morning.

If possible, I'd cut a slot in the ends of the tubes, deep enough to slip the disk into that slot. Would be much easier to weld then.

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Something like this.

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If you can't slot it like JayWal says, you might try laying two small beads on each piece of tubing, lengthwise about 90 degrees apart. Just add enough filler so it makes more of a flat on top, then flip the tubing over so those weld beads are like little feet that make it easier to weld to your plate. The extra material will make it more forgiving than the 16th in wall, and the fact that you don't have to reach so far into that crevice will make it much easier also.

BugHunter,

I had the same basic idea, but couldn't figure out how to put it in words, without writing a book. YOU got the idea across in just a few words. Well Done.

JayWal,

I don't know if it is a viable solution for the OP, but your solution would be the easiest of the various ideas to weld up. I didn't even think of using slots, while thinking of various ways I would tackle the problem. Good thinking.

I love this forum. More brains ARE better than none!

wouldn't making the material SUPER clean be beneficial so he is working with the base material and eleviating the oxide layer like Josh mentioned...OR...leave the oxide layer on the tubes to absorb the heat? Jay also has a plan of cutting slots, BUT, if the frame is going to lay flat on a surface the slotted material may hinder.

Thanks again for all of the input, everyone. Ultimately I ended up failing on this project but I feel that I've come away with a bit more experience and ideas. I tried the higher amps while attempting to follow the technique advice and also attempted to run a couple beads directly on the tube, but the tube kept collapsing into a sticky mess. I even tried smashing the end of the tube flat with the vice before lighting up but it would still just melt away like I see cast metals do.

I don't mean to imply that any of the advice was wrong / bad - I recognize that there's a skill and experience aspect that I don't yet have. I appreciate everyone's time.

Regards,

j

I bet if you had somebody there who could show you how to do it, you could get this done. There is no doubt about it, thin wall aluminum tubing is very challenging. Even for people that do it everyday, what you are trying to do is very tricky. You need some very subtle heat input. Then trying to weld to something heavier, it adds another layer of complexity.

I would turn the amps way down, somewhere around 50 or 60 and then try with a sharpened point on your tungsten, see if you can't lay a bead on that tubing. If you can add some thickness to that, this will become a lot easier. That's not to say it will be easy, but it will be a lot easier than it is now. LOL

If I had you in my shop with my Dynasty for about 15 minutes, your parts would be welded.

Do the ends of the pipes need to stay round?

If not.. You canm squeeze/hammer the ends flat you could probably also cut/grind the ends into 'V' shapes so they all fit/slot together and basically create a flat plane where you weld the pieces together from both sides. May not even need the washer at all.

Bye, Arno.

Dear Jaso hi! I run into a similar problem a couple of weeks ago to weld 1,2mm aluminum tubes. Given I mostly weld steel, every time I do some aluminum I run into the same learning curve

Any way, I resolved my welds this way:

Tungsten lanthaned 1,6mm gold tip
Torch angle 90 degrees.
AC balance no less than 85%
AC waveshape AAS advanced square wave.
Max amps 100.
Cup nro 7

I did find that if I punched heat too fast tubes would collapse. So I started the arc on the tubes at no more than 30 amps, then let the wave shape do the cleaning for me slowly and also preheating (no less than 30 seconds, be patient, stay there and let the heat build up), then gradually pushed the pedall down when a small shiny spot appeared on the bottom piece, mostly directing the arc towards it and leting the radiation heat from the arc heat the vertical one. When adding filler metal, moved the arc back slightly to have access to the puddle. The only filler on hand was 4043 of 2,4 mm so the beads where quite heavy but worked fine for me.

I hope this helps!

Regards:

Jerónimo.