How to tack with tig?

[deere2210]

I have 1/2"x1/2" square tubing (16ga) that I am trying to make a small cart frame out of. I matched the ends up and thought I would try the tig since I am trying to learn -vs- just breaking out the mig.. What is the right way to tack using a tig? I had the problem of burning through or not getting a good tack so the tubing would not stay connected.. Should I use filler for tacking or just fusion from the torch? I just wanted small tacks -vs- big globs of filler rod (which is what I ended up with)..

[zapster]

Try to get a puddle happening between the 2 pieces and just dip into the puddle with a drop of filler..

Drag the flame off the piece as you lift off the pedal and presto!

But you have to do it at the same time..

Sometimes you can fuse the pieces together but if it don't happen the first time filler is needed..

...zap!

[William McCormick Jr]

Originally Posted by deere2210

I have 1/2"x1/2" square tubing (16ga) that I am trying to make a small cart frame out of. I matched the ends up and thought I would try the tig since I am trying to learn -vs- just breaking out the mig.. What is the right way to tack using a tig? I had the problem of burning through or not getting a good tack so the tubing would not stay connected.. Should I use filler for tacking or just fusion from the torch? I just wanted small tacks -vs- big globs of filler rod (which is what I ended up with)..

Is it aluminum?

If it is aluminum and you are going quickly you have to add some filler to make it work.

If you are standing up the 1/2" x 1/2" bars on a flat surface, keep the heat at the flat surface a bit more while heating. Even let the puddle go underneath the tube. If it does not fuse add a drop of wire, come off the heat slow.

Sincerely,


William McCormick

[scubaholic]

always start your arc on the bigger piece sou you dont move the smaler piece in the process. it is difficult to tack with tig by your self. if you have someone to fit for you it is alot easier

[David R]

To make a tack, start a bead. When it gets going stop.

I don't use filler for carbon steel TIG tacks. A true tack is a small breakable weld......in case its not lined up properly....


David

[deere2210]

Thanks for the info, I'll give it a try.. I think part of the problem is there is a small gap between the pieces. It is 1/2"x1/2" (16ga) square tubing, but where they match up at a right angle there is still a small gap, that I was getting burn through..

I was running 60 amps using 3/32 red with 1/16 filler.. Does that sound right? I tried turning down to 50-55 but it really didn't start to puddle alot and then I would get burn through..

[David R]

you need more practice. 1/16" = about 62.5 amps, give or take.

David

[clark-kentski]

Do you have remote amp control? IE. foot pedal,fingertip control. You definitely need better fitment of your parts and me, i would drop down a size or two on the tungsten 3/32 seems a bit much

[tanglediver]

No Gap!

[pulser]

I've tried to describe this TIG tacking previously, it is one of the top ten "welding tricks" I've ever learned. This is a technique for TIG tacking without adding filler metal, and it is the only way to tack weld very thin sheet and wire. Can you TIG butt weld a joint of 0.035" SS wire?

http://www.weldingweb.com/showthread.php?t=12987

As mentioned above, a tight joint fit-up is essential.
When you try to TIG tack weld without adding filler, there cannot be any gap between the two pieces.
If there is a gap, the melted edges tend to "ball up" and "suck back" away from each other due to liquid surface tension.
If you approach the TIG tack slowly, with low current, trying to melt one edge and then the other, your are screwed, the melted pools tend to pull away from each other and do not "wet" together.

If you get the sharpened end of the tungsten as close as possible and aimed directly at the the root of the tightly fitting joint, and "Zap" tack weld it with a very brief blast of high current, the quick, concentrated blast of current melts both edges of the joint and wets them together.

[sn0border88]

what pulser said is the way to go for thin materials, but for 16ga tubing you should be fine.

Take the pieces in the corners so they pull less.

I would use .045 wire, but thats just me.

[papasloan]

Its the edge of the tubing that gives you the gap. Because its rounded.
Try laying the filler rod in the gap, Then start the puddle next to it on the horizontal and pull the puddle up to the rod and the vertical piece. And be sure to pull the filler out. You can fill the void this way.
For steel you can also melt a drop of filler in to the gap Then heat just the ball of filler until it melts and fuses with the surface.
For a lap ot tee joint if the seam is tight all you need to do is start a puddle on the horizontal and pull it up on to the vertical. Works especially well on stainless.
Butt joints can be a problem. On 16ga stainless tube I will pass the arc back and forth over the gap on both pieces to make the tack.
Hope this helped.

[mr2man]

Originally Posted by pulser

I've tried to describe this TIG tacking previously, it is one of the top ten "welding tricks" I've ever learned. This is a technique for TIG tacking without adding filler metal, and it is the only way to tack weld very thin sheet and wire. Can you TIG butt weld a joint of 0.035" SS wire?

http://www.weldingweb.com/showthread.php?t=12987

As mentioned above, a tight joint fit-up is essential.
When you try to TIG tack weld without adding filler, there cannot be any gap between the two pieces.
If there is a gap, the melted edges tend to "ball up" and "suck back" away from each other due to liquid surface tension.
If you approach the TIG tack slowly, with low current, trying to melt one edge and then the other, your are screwed, the melted pools tend to pull away from each other and do not "wet" together.

If you get the sharpened end of the tungsten as close as possible and aimed directly at the the root of the tightly fitting joint, and "Zap" tack weld it with a very brief blast of high current, the quick, concentrated blast of current melts both edges of the joint and wets them together.

Very cool, I just learned something new today! And a new feature of my fancy welder!

[Speen]

When tacking pipe pieces with a gap I start by warming up one of the pieces lay a ball on that piece, then I warm up the other piece and lay a ball on that one. Then I just repeat until they meet, and presto!

An other example would be tacking metal signs with stuff like S/N, weight, etc on to whatever. I align my tungsten so that the point is side-by-side with the metal sign, aiming for the piece in question. Adjust the amp's with the larger piece in mind. This often requires more heat to melt than the thin metal sign. That's why I'm not aiming at the sign itself, but at the piece. The sign only gets caught in the blast if you get what I'm saying.