beginner's luck

[slngsht]

So I finally got a little bit of time to play with the new TIG.

 

surprisingly, I had a pretty easy time welding steel (I've never touched a TIG, stick or oxy). Here's my 2nd attempt to weld:

 

http://www.usa7s.com/aspnetforum/upload/1655906440_CIMG2197.JPG

 

http://www.usa7s.com/aspnetforum/upload/993878401_CIMG2194.JPG

 

These welds were the easiest possible... tight fit between surfaces, etc...

 

After these, I tried Aluminum, and although I was able to make a weld without melting the pieces, they're ugly as hell... It's time to do alot more reading and practicing. I think pre-heating would have helped.

[JohnK]

If you have a "pulser" on your machine, learning to use it will make Aluminum welding work correctly. If you don't, learning to flutter the pedal at the right rate (roughly 1/2 sec period) will do. Aluminum turns to something not quite the consistency of water moments after it melts (you know this already) - you want to dial in enough heat to melt it, and then back off a tad so that it doesn't become a hole or something that runs away from you. This is a balancing act between pulsing the heat and dipping the rod directly into the center of the puddle (which cools the puddle just as backing off the heat). This is not easy to do for most mere mortals- your left hand has to become amazingly dexterous. It's a rhythm that you get going (at the start you may think that it's when the moon is in just the right phase and when the god that's in charge of such things (I forget his/her name) is smiling on your efforts) and your bead winds up looking like something out of a text book.

What I finally paid attention to that made Aluminum welding something I could do successfully and repeatedly was heeding the directions from all the instructions that speak to such matters is that everything (gloves, rod, tungsten metal, work surface, ...) had to be clean. This is true for steel too, but not so conspicuous as aluminum. If you see little black specs in the puddle, turn up the "cleaning" - that black stuff is soot and contaminates the weld, but more importantly will make it difficult to control the puddle. Soot can also be from not enough Argon - increase the CFM. That brown spot right of center on your lower photo is where the tungsten touched the puddle. When that happens, the steel wicks into the Tungsten which contaminates (weakens) your weld since there will be oxides produced in your weld. When that happens, stop and resharpen the electrode I have a local supplier who's specialty is abrasives - I got a Boro??? adhesive-backed disk to reshape the tungsten. The shape of this electrode is dependent on the power source you're using and the process ( AC or DC). Tungsten is really hard and commercial sharpeners use diamond wheels for this purpose. If you grind any metal other than tungsten with it, the other metal will contaminate the tungsten.

Persevere. Learning how to TIG weld opened up a world of stuff I'd only dreamed I could do, and new things keep appearing on the horizon. It's an incredibly enabling technology

Cheers,