[fattyJr]

Hello out there,

Started a new job in jan this year as a painter. The company found out I had previously been welding etc at work and at home so asked me to help out in the metalworking side of things during a busy period.

I can mig weld and tig weld, but run into a little problem with how they do things at this company.

They use a lot of 16 gauge mild steel sheet for manufacturing item and rely on a lot of tacks to hold items together (instead of small seam welds)

I have done tack welds in the past to hold things together prior to full welding, but they have always used a little filler. The company tend to do a lot of internal tacks that i can't seem to get right. I did a piece last week that was to the drawing, but they said i used TOO much weld and heat (was running around 45amp on a inverter tig unit and used 1mm filler rod and did 1/4" to 1/2" runs) All they want is a tack with no filler rod (just strong enough)

Problem is if i try to do the tacks at 45 amp, you have to hold in position for a little longer and tend to blow through. I have tried turning the heat up to just give me a 1/2 second (or less) pop of heat. I have tried different positions etc and can't seem to perfect this " tack "

Will try to get some pictures today to show exactly what i mean

[LtBadd]

Hello out there,

Started a new job in jan this year as a painter. The company found out I had previously been welding etc at work and at home so asked me to help out in the metalworking side of things during a busy period.

I can mig weld and tig weld, but run into a little problem with how they do things at this company.

They use a lot of 16 gauge mild steel sheet for manufacturing item and rely on a lot of tacks to hold items together (instead of small seam welds)

I have done tack welds in the past to hold things together prior to full welding, but they have always used a little filler. The company tend to do a lot of internal tacks that i can't seem to get right. I did a piece last week that was to the drawing, but they said i used TOO much weld and heat (was running around 45amp on a inverter tig unit and used 1mm filler rod and did 1/4" to 1/2" runs) All they want is a tack with no filler rod (just strong enough)

Problem is if i try to do the tacks at 45 amp, you have to hold in position for a little longer and tend to blow through. I have tried turning the heat up to just give me a 1/2 second (or less) pop of heat. I have tried different positions etc and can't seem to perfect this " tack "

Will try to get some pictures today to show exactly what i mean

When tacking with no filler be sure you have a good fit up, no gaps, metal is clean, and keep a tight arc. If you draw the tungsten away it spreads the heat out, you won't get a puddle as quick and in thin material, as you discovered, it can cause you a lot of grief

[Oscar]

Fit up is the most important part. Once that is there, you need to experiment with the amperage. Depending on your arclength and torch angle, you may need upwarda of 1.5x the normal amperage. 45A typically won't work unless it's stainless. For mild steel try 70-75A. Again ago this will vary on a few factors. You need to try it for yourself and remember that there needs to be zero gap, other wise you will be chasing your own tail. Also try using a very long taper on the tungsten, about 3x diameter.

[fattyJr]

Thanks for the tips, Will have a crack at what was suggested.

[Markus]

Try to use fast pulse. Lowers heat input, but also it tends to suck up corners together much better.

[Otto Nobedder]

I "pulse-tack" stuff all the time, stainless and carbon, in thicknesses from 16 ga. to 1/4". I set the machine at 200+, and floor it for about three-fourths of a second (that's about a half-second of pre-flow and a quarter-second of blazing heat).

If the fit is tight, it works every time.

40A will not do this.

Steve S

[Oscar]

I "pulse-tack" stuff all the time, stainless and carbon, in thicknesses from 16 ga. to 1/4". I set the machine at 200+, and floor it for about three-fourths of a second (that's about a half-second of pre-flow and a quarter-second of blazing heat).

If the fit is tight, it works every time.

40A will not do this.

Steve S

yup, 40A is like holding a lit match-stick to a stick of butter. Just gonna melt things in not such a good way and makes a mess