Tig Welding help

[Jefe]

Trying to self teach myself how to Tig and it's going well, except for my beads are not buuilt up very well. I get good penetration, I can work the puddle pretty good, it's just not getting built up. Am I wrong for looking for a raised bead like Mig welding?

[lowbflat]

If you hold your torch like a pencil you'll have better control. Move your torch around in a circle to "puddle". Add some rod and move forward a bit, puddle more and add rod. As you get better at it, things will move faster. Welds will be flatter than MIG because there isn't as much filler rod added.

[satan]

x2 - there is a definite strirring, and TIG if much flatter (and less disturbed) looking than MIG... If you're worred that you do not have enough build up - add more fill (is your weld "below" the material surface? IMHO at or slightly above is fine...)...

Truthfully, a second and seasoned set of eyes may be all you're really looking for. Run a few coupons past someone in the game and ask for their input.

[Special Ed GT]

x3 - if you're getting good penetration and can work the puddle, then just add fill rod and you're there! What thickness material are you working with and what size fill rod are you using? Post some pics and let's see what ya got!

[Jefe]

I'll try and post some pic's up tomorrow when I get home from work. The depth is just a little below the surface. Because it's at work I am limited to the scrap that I have. It's both a thin walled square tube, or 1/4" channel. I have mainly been practicing with the square, kinda helps me learn how to regualte the pedal so I learn not to burn through. Thanks for the help guys!!

[Jefe]

Ok here are a few pics. Pics arent as clear as I hoped but I think you can see. The peices are about 12" long by 1.5". Not trying to build anything really, I was just trying to practice long runs and angels.

http://www.colorado4x4.org/vbb/attachment.php?attachmentid=3494&stc=1&d=1148392224

http://www.colorado4x4.org/vbb/attachment.php?attachmentid=3495&stc=1&d=1148392224


http://www.colorado4x4.org/vbb/attachment.php?attachmentid=3496&stc=1&d=1148392224


http://www.colorado4x4.org/vbb/attachment.php?attachmentid=3497&stc=1&d=1148392224

http://www.colorado4x4.org/vbb/attachment.php?attachmentid=3498&stc=1&d=1148392224

[satan]

What I'm seeing is that you're joining square tubes?

The heating looks pretty good actually given the "new to TIG" thing...
Remember that tubes have a radius on the corners so it will require more fill (like grinding bevels to edges of thick stock- think like " \-/ <--- your weld is there at the bottom of that valley".

There's some additional heat pulled to the "center" of that type of weld due to the doubled thickness of material (again assuming that this is square tubing...)

For me - go with a triple-pass for build up instead of adding a lot of filler on one pass (that'd be A LOT of filler in one pass, and likely get a lot of heat into things)...

Add two more passes in that little valley (each off the center-line by about 30% of the existing bead) ought'a get you something strong, built-up and purty without having to cook a big-ass puddle...

[Special Ed GT]

The way I'm reading your post, it sounds like you're just using the square tube because that's what you have to practice on. That's a good start; if you need some round tube I usually have some small scraps that you can have for practice. Round is alot trickierier but from the looks of things you'd get the hang of it quickly.

I see alot of heat in your welds and not enough fill rod - that goes hand in hand, since more fill rod cools the weld. I'd recommend that you keep the heat the same and add more rod to raise the bead slightly (like, very slightly) above the parent metal. Then, bump up the heat a little and try to go the same pace with the same amount of fill rod, and you should see a difference in the height and width of the bead. Change one variable at a time and you'll begin to see what differences in technique are needed depending on the type of joint, material to be welded, and fill rod thickness.

Just my opinion, but I would not do multiple passes while TIGing. One good pass on a tight, well-fitted joint is enough. Remember with TIG, the closer the fitment the better. Regulate the heat and add more fill rod to build-up the weld in one pass. If you don't have good fitment and need to do multiple passes to get a strong built-up weld, why not do a single pass with a MIG and be done with it?

Hank

[Jefe]

Thanks for the help guys. Yeah, the square tubing is really all the scrap I could find at work. We have alot of aluminium scrap (airplane structural parts) but I am not ready to tackle alum welding yet. I am having problems burning through on the ends (fairly thin tubing) but I guess that will come with more practice and trying to get into tight corners and keep it clean.

Hank I may take you up on the scrap tubing.

[Special Ed GT]

No prob, happy to help. Lower your heat slightly at the end of the weld and add a little more fill rod to help reduce burn-thru. Tight corners are tough but it sounds like you'll get the hang of it soon. What voltage setting are you using? I usually set the machine at 100 max for DOM and other thicker tube.

Hank