Thread: Filler rod size for TIG

Gidday

I love picking up stuff from forumites! Thx for the insights Karl top post!!!!

Regards Lou

One thing I was told about TIG many years ago (and not just for Al) is that the sound of the arc is a good indicator of whether the settings are right. With some practice I'm beginning to hear what they meant.

Karl, the material was cut with a guillo or shears - no lubricant involved. Good point about ramping up the heat quickly - another thing I do sometimes but need to be more conscious of. More practice this weekend...

Michael

Um..............I think you mean Mig

No, I do mean TIG. The sound changes subtly when the amps are about right - not as high pitched?

Michael

Gidday

M8 if that works for you................... you got better ears than mine! I usually have earplugs in when Im working and besides I can hardly tell when these new inverters are on!!!! The only way i can is if the Led display is Litup!..............Laughing I must be going deaf!

Ive done a lot of training in Tig recently and the best advise I can pass on is to look at your weldpool its the single most important Indicator that tells you your in the ballpark for a good setting...............

To be honest I havent done as much work as Karl on Aluminium hopefully he might comment about what he looks for in a Weld Pool???????

Regards Lou

Originally Posted by NewLou

Gidday

M8 if that works for you................... you got better ears than mine! I usually have earplugs in when Im working and besides I can hardly tell when these new inverters are on!!!! The only way i can is if the Led display is Litup!..............Laughing I must be going deaf!

Ive done a lot of training in Tig recently and the best advise I can pass on is to look at your weldpool its the single most important Indicator that tells you your in the ballpark for a good setting...............

To be honest I havent done as much work as Karl on Aluminium hopefully he might comment about what he looks for in a Weld Pool???????

Regards Lou

As you said MichaelG, there are subtle changes to the arc sound when adjusting Tig, but they are very subtle, varying between welders also, making them a bit hard to read for new players.
What to look for in the weld pool? Well, lets start at the beginning, you have hit the trigger and your arc has initiated, you should see small particles of aluminium oxide being blasted off the material and a shiny area appearing fairly soon, this will vary between say, less than a second for 1.6mm material up to 30 seconds when welding a heavy fitting into a 6mm thick tank. If you linger too long, you will notice that the 5 or 6mm dia weld puddle will begin to widen and widen and widen until - PLOP, there goes your sheet in a lovely blob on the floor. We don't want to do that, so when we had our nice shiny 5-6mm puddle, we added a little filler material into the leading edge of the puddle and slightly withdraw the filler, keeping it within the shielding gas envelope - don't let it melt in mid air and drop into the puddle, when added, we looked to see that the filler melted off cleanly and was smoothly drawn into the puddle, if it sat up like a pimple, we either pause a little longer to add some more heat or increase our amperage input - experimentation will teach you which one is right on the day. Now for the tricky part that needs the coordination, we move our tig torch and filler rod holding hand along slightly and dip our filler once more into the leading edge of the puddle looking for the clean melt and smooth transition from one ripple to the next. Repeat until you get to the end of the joint, then add a bit more filler than you normally would, take your finger off the trigger to let the arc extinguish, you will notice the puddle suck back and even a slight crack may appear, (typically on a restrained butt joint), hit the trigger again to reheat the puddle, add another dab and let the trigger off. Do this until your crater is full and maybe even give it a hit without adding filler last of all. This cools the end of the weld gradually. True,you could use the crater fill setting on some welders, but I prefer this method because I can control it for each individual weld which is often crucial when doing repair work, (think crack in the middle of a cast aluminium sump that want to keep cracking when it cools).
Examine your weld, it should be nice and shiny with a consistent width, if it looks frosted then you have too much heat input and either need to drop your power or travel faster, yellow or black specks indicate contamination which needs to be addressed.
If it all starts to go pear shaped and get away from you, all is not lost. You can either let off the trigger and start again, (letting off the trigger allows some of the heat to be heat sinked away by the sheet), sometimes a larger dose of filler may bring things back under control.
Little pointers on the whole operation.

• Get yourself comfortable
• Breathe, you would be amazed how many people hold their breath while welding
• Hold the tig torch so that you control it
• Don't drag the gas shroud, there is a technique known as walking the cup used on steel and stainless - it is a fatal mistake on ally as the gas shroud will have enough heat in it to melt the ally and spoil your nice bead.
• Hold the filler wire close enough to the end so you can control it and then feed it with your fingers, it takes practice but once you get the hang of it you will love it
• Don't lift the torch away until the post flow has finished, not so bad with ally, but if you do this with stainless, the end of your weld oxidises as it cools and is harder to clean up
• Keep a consistent arc length, a longer arc means a wider weld. Arc length means everything with tig - particularly when working with stainless.

Originally Posted by Karl Robbers

Little pointers on the whole operation.

Great info Karl... I'd like to add:

• plan ahead - when you're coming to the end of the weld, particularly near an edge you need to anticipate the build up of heat and back off the amps accordingly, and be ready with the filler to help control it.
• grind or drill out any contamination (like a tungten inclusion) - don't try and weld over it, it's just not going to end well.

Regarding you're previous comment about using 3.2mm filler exclusively: I found I was using 2.4mm exclusively for everything just out of habit, but on one 'off day' on some thin stuff, I reverted to 1.6 and was pleasantly surprised at just how much easier things were...

Cheers

- Mick