TIG cup grinding
Posted: Fri May 28, 2010 3:01 am
I was welding a tricky joint that needed more tungsten stick-out than I had a cup to enable (the largest cup I had was a size 8, gas lens type.) The largest the local welding supply had for my torch (a type 17) was a 10, non-gas lens, which I bought but it didn't do the trick. I figured I needed about 3/4" of stick-out for my joint...
I managed to modify my gas lens cup into a large (size 11-12) "shortie" by grinding out a gas lens cup. I tried grinding it on the bench grinder, which kind of worked, but left a bit of a ragged finish and wore down the grinding stone by about as much material as was removed from the alumina cup.
I finished the cup grinding with a diamond rotary burr, of the 1/4" arbor variety, with a head diameter of about 3/4". (I bought it previously to grind on stone.) This wasn't real fast either, but it did leave a nice finish and didn't wear out the tool at all. I kept it misted with a water sprayer during the grinding... and kept the grinding speed down so the water wouldn't immediately get slung away. I think a carbide burr would have worked too.
I was pleased that it worked so well, as I was able to get good shielding gas coverage out a lot further than any other cup in my posession allowed - I tested a full 3/4" stick-out on flat aluminum, (with I think 20+cfh), and I got a nice shiny weld puddle, free of black smut. No other cup I owned came close. This might be an OK setup for titanium...
Also, the tapered shape near the tip of this "custom" cup could be a useful feature, as it could allow you to get the cup a little closer to an angled obstruction.
I will consider doing more similar "cup modifications" in the future if I need something that I done have, or they don't make... For getting into a tight joint that the cup is bumping against something... I will consider just grinding down the cup now! New cups only cost about $1.30 - $2 ea, so I figure they are cheap enough to experiment and if it doesn't work out, no big loss.
Thought you might want to know this trick!
I managed to modify my gas lens cup into a large (size 11-12) "shortie" by grinding out a gas lens cup. I tried grinding it on the bench grinder, which kind of worked, but left a bit of a ragged finish and wore down the grinding stone by about as much material as was removed from the alumina cup.
I finished the cup grinding with a diamond rotary burr, of the 1/4" arbor variety, with a head diameter of about 3/4". (I bought it previously to grind on stone.) This wasn't real fast either, but it did leave a nice finish and didn't wear out the tool at all. I kept it misted with a water sprayer during the grinding... and kept the grinding speed down so the water wouldn't immediately get slung away. I think a carbide burr would have worked too.
I was pleased that it worked so well, as I was able to get good shielding gas coverage out a lot further than any other cup in my posession allowed - I tested a full 3/4" stick-out on flat aluminum, (with I think 20+cfh), and I got a nice shiny weld puddle, free of black smut. No other cup I owned came close. This might be an OK setup for titanium...
Also, the tapered shape near the tip of this "custom" cup could be a useful feature, as it could allow you to get the cup a little closer to an angled obstruction.
I will consider doing more similar "cup modifications" in the future if I need something that I done have, or they don't make... For getting into a tight joint that the cup is bumping against something... I will consider just grinding down the cup now! New cups only cost about $1.30 - $2 ea, so I figure they are cheap enough to experiment and if it doesn't work out, no big loss.
Thought you might want to know this trick!