any advice on thin TIG stuff?

[g-wizz]

so i brought some 18 gage into class and i was wondering if there are any specific tricks to doing thin stuff. for 18g to 18g i was at about 50amps, but alot less on the pedal i tried 40 but it was to slow for filler i was using .035 mig wire. also im using 3/32 tungsten which i think is probably to thick. i guess my real quiestion is that when you weld thin stuff do you use different torch angles than thick.. while doing it i noticed that i almost had to have my torch paralell to the face of the none base plate of the T joint instead of 45*.
uh here are some pics. here are some pics.
looks really overheated but its the camera
http://i269.photobucket.com/albums/jj77/IWILLSTABYOUALOT/Picture056.jpg
http://i269.photobucket.com/albums/jj77/IWILLSTABYOUALOT/Picture055-1.jpg
i was going to ask my teacher this stuff buttt i was welding till the end of class and he hade to go home.

[BumpyDodge]

Were you welding on top of a thick metal table?

[DSW]

My tig calculator for steel only goes down to 1/16". For that it suggests a 1/16" tungston. I would think that you want to be at about 50amps or there abouts. I agree that the table might act as a heat sink to keep the base cool. Try setting it up on some small strips or short rods.

[Bigger Valves]

Yea, they look pretty rough. Thin is a different ballgame and truly takes lots of doing. I can have someone laying nice beads on heavy stuff in just an hour or so. Thin material takes days and some will never get it. Smooth, consistent, and steady. Read the puddle. Find your tune for those things and you'll be good to go. Also, don't heat soak a part, thin material shows where you aren't patient everytime.

[g-wizz]

Were you welding on top of a thick metal table?
maby about 1/4" thick? so yes? ill try that next time.

Yea, they look pretty rough. Thin is a different ballgame and truly takes lots of doing. I can have someone laying nice beads on heavy stuff in just an hour or so. Thin material takes days and some will never get it. Smooth, consistent, and steady. Read the puddle. Find your tune for those things and you'll be good to go. Also, don't heat soak a part, thin material shows where you aren't patient everytime.
this was litterally my first time welding somethign thinner than 1/8. my arc kept jumping around and even with fusion welds the puddle was alot larger than i wanted it to be. is that because of the size tungsten im using? or what? i guess ill just try different stuff and see what happens. it kindof sucks that i only get to do this once a week so in a way i almost start over every week but ya.

another quiestion.. im constantly having problems having to reposition my self while laying down beads... what i mean is that ill have a good position and torch angle for about an inch or so then i have to stop reposition and then start welding again. when you guys weld how do you support your selvs? assuming your at a booth/table are you on your elbows or for arms ect...? what do you find to be the most comfortable/moveable position.... (stupid quiestion right since comfort is realitive only to the person comfortable)

[jeepfreek383]

something like that i would set the heat at about 55-60 have your tungsten out about 1/8" and walk the cup . i would use a #6 or 3/8 cup. lay your filler right down in the groove and walk your tungsten back and forth using the cup as the pivot point. go slow and watch the filler fuse to your base metals. on smaller metals you can grind that tungsten down to a pinpoint if you want it will give you a tight, precise arc. and move slow, back and forth ..you'll get it. and with steel you dont need to add a bunch of filler, its more about fusion. with aluminum you need to add a lot more filler to keep the joint from cracking

[BumpyDodge]

maby about 1/4" thick? so yes? ill try that next time.

...my arc kept jumping around and even with fusion welds the puddle was alot larger than i wanted it to be. is that because of the size tungsten im using? or what? ....

You said you had to keep the torch pointed down in the OP, which is why I assumed you were welding on a steel tabletop. The table top is acting like a big heat sink, so in essence you aren't welding 18 ga to 18 ga anymore - you're welding 18 ga to 3/8". Put an air gap under the bottom piece and they'll both melt-in at the same rate. If you can, just put both pieces so you're filling a valley (1F instead of 2F position). When you can position the work on the bench any way you want, don't make the weld position more difficult than necessary unless you need to practice/test for a cert in that position. Always use gravity to your advantage.

If your arc is literally jumping all over the place there could be two possibilities: A contaminated/improperly ground tungsten, or magnetic arc blow.

Regrind your tungsten to a sharp, but *truncated* cone (leave a little .020-.035" dia. flat on the end -not needle sharp). Make sure the grind marks are parallel to the point, just like almost every welding book shows a picture. A 1/16" tungsten would be better than a 3/32" for 18 ga. but if 3/32" is all you have, it will do. 40 amps sounds about right. TIG calculators can be misleading - just set the machine to what works for you. If you're using an inverter TIG or working with pulse, don't even bother looking at the calculator because it's going to be pretty far off.

If you've got magnetism on a low amperage weld, it's going to make your life miserable. You don't need a $75 magnetometer to check for it:
1) See if the workpiece will pick up steel/iron shavings (In a metal shop, metal filings are not hard to find). Ditch any magnetic clamps you're using.
2) Check your torch and work leads to make sure they aren't coiled up or wrapped around anything.
3)If you have a magnetized workpiece, wrap the work lead around it a few times and make a few *AC* welds on a piece of scrap metal. The AC coil around your workpiece will help knock any residual magnetism out of it.
4) Recheck for magnetism, switch back to DC and weld away.

If you still have a wandering arc after all of this, repost and we'll fix from there.