TIG inside corner with gas lense?

[jeffscarstrucks]

I am trying to figure out the correct set up to weld an inside corner welding a piece of .125 x 2 AL angle to a flat piece of .100 plate. You have an 3 sided inside corner to get into. I am using a #9 torch with a 1/16 tungsten and a #6 gas lense cup. The material is clean. The machine is set to %80 DCEN, 180 or 200 hz and 80A but mostly at 60-75A use. I can get a nice tight bead in the open but when I tried to extend the tung to 3/8-1/2 stick out I was loosing coverage. I tried the gas at 15, Then 20 with the same results. Am I missing something with the lense use or do I just need more flow? I have not used a lense before but I thought that this was the kind of application that they were most often used in. I did finish the job but the results were not what I had hoped for in the corners These parts are deep in the hull of a twin diesel boat so it's more of a personal challenge than anything else. Thanks in advance, JEFF

[HAWK]

Jeff,

My guess is the cup is too small for your gas lens for that length stick out. You can crank up the CFH, but can also get to much flow and defeat your purpose by drawing in the surrounding atmosphere and contaminating the weld. The gas lenses come in small medium and large. Be sure the insulator between the lens and the torch is the correct size so you don't loose gas around the cup to insulator seal. The seal is between the cup and the torch head. If it is too small you can leak shielding gas on either or both sides.

[BCarlucci]

I use the gas lens all the time for my tig welding, and i normally have my flow set at 30-35, i'd go with a little larger cup size, i would use maybe a 7 or 8, i know there's not much difference between the 6 and 7 but it might be worth a try. I hope this works out.

BC

[jeffscarstrucks]

Thanks guys, I,ll pick up some larger cups and try it again. These parts went out yesterday so I'll make up a couple of practice pieces to experiment on. I have never run the gas that high but I'll run 'er up and see what happens. Is ther a common danger zone where you start to see puddle aggitation or contamination from too high of a flow rate? I have used 15cfh as a norm and always figured that 20 was high.Most of my work is inside so maybe that's why I gotten away with not having gas blown away at the low rate. Thanks, JEFF

[HAWK]

Jeff,

You are in the ball park when it comes to straight out plain jane torch set ups. When you add the gas lens there are lots of little screens that diffuse the gas. It takes more to get the job done. You should see improvement as the flow increases with the larger cup. I have run as high as 45 CFH with a large lens and a trailing diffuser on titanium. Experiement. You will know in a "flash" when the flow is too much.

[jeffscarstrucks]

Thanks again, I think I have been a little confused by some ads that call their gas lense a "gas saver" because of the more concentrated area of coverage. Do you think that once I arrive at the right set-up for this that a nice clean consistant bead is achievable all the way into the corner on a joint like this? That question probably is as dumb as it sounds but I feel like this is one of those things that I'm suddenly lost on and I want to get a handle on it.

[HAWK]

The best available is the only way to buy.

jeff,

Try CK products worldwide. They are GTAW specialists and make some of the best torch accessories available on the market today!

http://ckworldwide.com/ Home Page

http://www.ckworldwide.com/Gas_saver.htm What you are looking for???