[jakeru]

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!

[jakeru]

Although the large diameter gas lens setup was working for my tricky weld joint, its fatter base was limiting my range of motion (reaching into a tube welding the inside) compared to a standard collet body, so I tried a different approach.

I ground another tig cup (this one a #5, standard collet body) so I could get up close to a very tricky weld joint (welding inside a bent tube) without having to stick the tungsten way out. I ground off one edge of the cup, at about a 45 degree angle as you can see below, so I could get the tungsten in closer without having it stick out so far from the cup.

The angle ground cup did the trick! I had to build up some aluminum 4043 material inside an aluminum intake manifold runner tube. I couldn't even see the puddle when I was welding; I had to stop and stick a small mirror up into the tube to see it. I added filler rod down into the tube from the other end. The ground cup allow me to get it done!

The local welding supply who helped me brainstorm how to do this, thought it wouldn't be possible without a (not cheap) "micro" TIG torch.

[speedfreak87]

I have a stupid newbie question, and I don't know why my teacher didn't discuss this, but what does the gas lens do exactly?

[jpence38]

Check this link out ................http://www.weldcraft.com/2008/01/gas-le ... s-for-tig/