Welding Tips and Tricks

Good Afternoon!
So I have to TIG weld some 3/16" plate together (butt weld) and I wanted to ask how some of you would go about doing it.

Would you go for a single pass weld with no bevel?
Would you bevel and multi pass with lower amps?

Im curious because I tried to do a single pass with no bevel and the puddle gets pretty large. I was using about 150 amps with 3/32 filler. I think a multi pass weld would have looked a lot nicer.

I guess it depends I would bevel and root pass for the strength it provides. If your concerned about profile being above surface than bevel and do a root cap pass. Pretty thin for many passes. 125 amps max IMO with pedal you can always run 150 and modulate.

I would gap and bevel, but I am not sure that necessarily means multiple passes. It kind of depends on your machine and ability I think. you'll be running at least 170 amps or more if you are trying to single pass it. Try a sample and play with the gap and the bevel angle and see if you find a combination that gives you full penetration and enough bead profile.

If it's a one time thing, or only comes up on occasion, play it safe: knife edge bevel, tight 3/32" gap, small root pass 80 amps watching it keyhole.
I use a 3/32" rod so I can "freeze" the keyhole on each dip.

Fill it on the next pass, or 2 fill passes if you need them. Increasing amps as needed, 150-160 amps works pretty good.

TIG penetration is best done with the grinder in my opinion.

If you'll do a lot of them at a time, more playing around with settings can get you a faster result.
What I wrote is just a fairly slow, but easy to do, method that works because you can watch the keyhole.

Full credit goes to Jody's channel. I wouldn't even have tried it that way if I hadn't seen how easy the keyhole technique is on his videos.
For class I demonstrate it with a lift-arc ESAB 161 (no foot control). Works on 1/4" too.

Can you get at both sides?

weldin mike 27 wrote:Can you get at both sides?

Good point, I was describing a method for welding from just one side.

MinnesotaDave wrote:If it's a one time thing, or only comes up on occasion, play it safe: knife edge bevel, tight 3/32" gap, small root pass 80 amps watching it keyhole.
I use a 3/32" rod so I can "freeze" the keyhole on each dip.

Fill it on the next pass, or 2 fill passes if you need them. Increasing amps as needed, 150-160 amps works pretty good.

TIG penetration is best done with the grinder in my opinion.

If you'll do a lot of them at a time, more playing around with settings can get you a faster result.
What I wrote is just a fairly slow, but easy to do, method that works because you can watch the keyhole.

Full credit goes to Jody's channel. I wouldn't even have tried it that way if I hadn't seen how easy the keyhole technique is on his videos.
For class I demonstrate it with a lift-arc ESAB 161 (no foot control). Works on 1/4" too.

Yes, the keyhole method is a nice sure way. When I used 150 amps and no bevel, I almost got through, but the other side was pretty gray from no argon coverage.

How do you do lift arc with no foot control and control the puddle when you get to the end of the weld. For example, when I co.e up to the edge of the plate, I need to lift up on the foot pedal or it melts everything away.

weldin mike 27 wrote:Can you get at both sides?

Yes I can get to all sides.

Ant428 wrote: How do you do lift arc with no foot control and control the puddle when you get to the end of the weld. For example, when I co.e up to the edge of the plate, I need to lift up on the foot pedal or it melts everything away.

If your TIG box doesn't have slope control, you can't. Its either Arc ON or Arc OFF with Lift Arc in the absence of amperage controls. This is where you see experienced welders apply an extra dab or two at the end, and snap off. They will come back as needed and grind down that end of the weld to fit/suit the application.

cj737 wrote:

Ant428 wrote: How do you do lift arc with no foot control and control the puddle when you get to the end of the weld. For example, when I co.e up to the edge of the plate, I need to lift up on the foot pedal or it melts everything away.

If your TIG box doesn't have slope control, you can't. Its either Arc ON or Arc OFF with Lift Arc in the absence of amperage controls. This is where you see experienced welders apply an extra dab or two at the end, and snap off. They will come back as needed and grind down that end of the weld to fit/suit the application.

What he said^^^

Normally if I add and extra dab or two, and snap out just right, you won't really notice much difference in my termination.

Really gets hidden if that is also where I'm starting the next bead - like a direction change (around a corner).

Also helps me if I have a tack right there that gets re-melted and added to the termination.
The more heat that I'll have built up when I get there, the bigger the tack I leave there - it's probably cheating in some way

In something 3/16 thick (5mm) I would have no gap and a small 1mm prep on one side. 150 amps can be reasonable expected to melt 2-2.5 mm in from both sides and therefore you'll get a nice strong weld that wont require the skill of keyholing.

weldin mike 27 wrote:In something 3/16 thick (5mm) I would have no gap and a small 1mm prep on one side. 150 amps can be reasonable expected to melt 2-2.5 mm in from both sides and therefore you'll get a nice strong weld that wont require the skill of keyholing.

Thanks for the reply. When I use 150 amps, and 1/8 rod, the weld is gray and looks awful . It looks like I went too hot. What's the reason for this? Moving too slow?

I never have 1/8 rod. Never even use, 5/64. I only use 1/16 but then again I don't need to use much filler. Grey colour on the weld is a sign of poor gas coverage. A number 8 normal gas shroud should give you a decent coverage and have a tungsten stick out of only less that 3/8.

Using that thick of a rod on this job at this amps will suck out all your heat and make it difficult to get the weld flowing