Welding Tips and Tricks

Still very new to Tig, so I'd like to work out what I'm doing wrong here.

What do you think the base metals are and what filler rod are you using?

-Sandow

Filler rod was 316, fittings were all 316 and I'm fairly certain the keg is 316.

Looks like you didn't have good argon coverage. Were you pulling the rod out of the gas shield between dips? Was there a breeze where you were welding?

I probably was pulling the rod out of the gas shield between dips due to the position I was in. I thought my gas pressure was plenty (without being too much), around 10L/m. Maybe I should switch to a gas lense?

Did you back purge that keg before you welded it? That helps your puddle behave but it looks like really laid the heat in there. You are likely to get cracks in the HAZ. I do quite a bit of keg welding. They are 304 series, 18ga. and purging is a must. I usually weld fittings on at about 55 amps and concentrate the arc on the thicker fitting and wash down onto the keg with 309l rod. The gray look of your welds means you used too much heat. You welds should be that nice straw/salmon color. You need to get in and get out on stainless. Weld a little and stop, use a wet rag to draw out the heat and then weld a little more, rinse and repeat.

exnailpounder wrote:Did you back purge that keg before you welded it? That helps your puddle behave but it looks like really laid the heat in there. You are likely to get cracks in the HAZ. I do quite a bit of keg welding. They are 304 series, 18ga. and purging is a must. I usually weld fittings on at about 55 amps and concentrate the arc on the thicker fitting and wash down onto the keg with 309l rod.

Good tips mate, much appreciated. I was using around 65 amps from memory and had done a quick dodgy purge, but admit that it probably wasn't sufficient.

This is how it should look. Its been wire brushed but you get the idea. Using not enough amps is just as bad as too many. Not enough and you will overheat your base trying to get a puddle, too many amps and you blow holes. I would recommend a bit of practice before going at a good keg. Pick up a clunker and practice on that first. Stainless welds really nice but you have remember it doesn't conduct heat worth a damn and the heat builds up as you are welding and all of a sudden you have a big hole drop out. Good luck. PM me if you want more pics and pointers.

The comments about back purging certainly have merit. If the outside looks grey, the inside may well be sugared. It is worth taking a look if you are going to be putting liquids through it.

My guess at the overall problem would be insufficient shielding and too long of a welding time. A jumbo gas lens and higher amps and some pulsed welding will likely bring it into line. Grab some scrap and try a few things out. Stainless is finicky.

-Sandow

- Change your collet body to gas lens.

- I'm pretty sure that you have a gas leak in your system. Check every connection/joint with soapy water or so and make sure
you wont get any bubbles. Your welds does look like there have been a lot of oxygen mixed into shielding gas.
Oxygen tends to make welds pretty ugly and also weld puddle is much harder to control. So you don't want it in the shielding gas.

-Stainless welds don't need to be pink in color. That is common misconception. Even in pink colored stainless welds corrosion resistant is reduced a lot! So that in mind color does not tell almost anything as long as you have had proper shield over weld puddle. All that matters is heat input and that needs to measured in different ways than checking a color of the weld, because you can over heat weld with big gas lens and still get a neat color.

Little fun fact too
Did you know that in TIG orbital welds there have tried out mixed gases that contains few ppm's of oxygen??? This was tested because oxygen is cheap and when mixed into shielding gas it creates deeper penetration than plain argon. Which means better penetration and increased weld speed.
Why it's not used today though? Because it does create ugly welds, puddle control is not that good, it can create color in to the pipe root and it tends to wear tungsten faster than wanted to.

Wow, great tips guys, much appreciated. I'll check my gas lines and get myself some stubby gas lenses.

Reply us when you got some new results