Problems with TIG Fillet welds on 14 guage 1" Square Steel Tube

[kraythax]

I am a hobbyist trying to add TIG to my repertoire of welding and I have been doing pretty well so far with some hiccups. Since I want to build some stuff with tubing, I have a long stick of 14 guage 1" square steel tubing and to practice I have been cutting it into random chunks with some mitres and some square cuts and then welding the pieces together, sometimes in a square 90 degree angles, sometimes straight, sometimes T shaped welding and it is the last one I am having a problem with. I am using a 3/32 lathanated tungsten, PrimeWeld 225x, 100% Argon, 75 amps DC and 0.045 filler rod. When I try to make fillet welds on the tubing and I hold with the tungsten pointing right at the corner I often dont form a puddle at all. If I put in filler wire I have to feed it in, sometimes half the wire, to establish the first bead. I tried melting off the vertical wall for the fillet first then floor and vice versa. What it boils down to is I am getting decent welds in other positions but this one I cant seem to get and its frustrating. Either I put in too much power and it blasts through the thin tubing or I dont put in enough power and dont get a puddle and am not technically welding. Any advice would be appreciated.

[LtBadd]

You may have too long an arc, keep a tight arc, don't set the machine too high (amps), if you need a 100 amps set it to 125 and then use the pedal. If the machine is set too high you'll lose
some resolution in the pedal.

[wb4rt]

If I understand, you are welding an end of the tube to the middle of another piece of 14 gauge. If that is the case, I believe your problem is from the gap where the rounded corners are. Either cope the end for better fit up or tack the middles first on flat sides. Work from middle to corner to other middle. Allow some cooling time to avoid too much heat. You have to move fast or you will burn through. Try a 3/32 filler rod. You need enough filler to cool the puddle and fill in the gap.

For practice I recommend 11 gauge (1/8”) tube. Gives you more latitude while learning.

[Oscar]

I think 3/32" (0.093") filler on 0.072" steel is a bit a stretch, no? I think 045 is adequate, and 1/16" would be perfect.

I often dont form a puddle at all.

Your description is good except this. Then what does happen? Nothing? Just heats up the tube? What is your actual arc length? No guessing, but the actual number?

[kraythax]

I have tried to keep the arc length short as possible, 1/8 to 1/4 inch but of course I need practice. The advice on coping the t joint might help but I don't think that is the problem.

When I don't form a puddle , I tried to angle the arc to the standing tube and that melts steel in a micropuddle under the arc but not enough to puddle or push down to even tack the parts.if I increase I get material melt but a fine line for burning through. I can stuff in filler but then I am concerned I am just melting material to the surface without penetration.

[12V71]

Try a bit more stick out on your tungsten or maybe a smaller cup to get closer. The extra stick out will make it easier to dip, but will get the arc in the area it needs to be in.

[Dave66]

I have tried to keep the arc length...1/8 to 1/4 inch...

Too long of an arc. Try to get under 1/8" (closer to 1/16" is better).

[shovelon]

Sounds like your amps are way low. Crank that machine up to 200amps and hit the pedal. The one amp per thousands of inch is kind counter-intuitive if you have a foot control to adjust the amps on the fly. You should be able to fuse the joint without filler at all if you punch it.

3/32" diameter filler would be useful to fill a j-groove fillet joint. Melt, cram the rod, and jam forward. Melt-cram-jam-repeat.

Another thing is grind a pencil like taper with a needle point to get tight into your corner. These 45 degree grinds are hard not to keep the arc from wandering. Blunting the point makes wandering even worse. Never did understand dull points.

[Oscar]

Too long of an arc. Try to get under 1/8" (closer to 1/16" is better).

Yup, I too had a feeling he was using too long of an arc length. I concur, 1/16" arc-length with a long needle taper will yield much better results.

kraythax, you can use a 1/16" filler rod to gauge your arc length, before striking the arc. Place it in between the tip of the tungsten and the joint, and hold that steady, and mash the pedal. Don't worry about blowing through on these practice parts, as that is what they are for.

[Willie B]

Shovelon said it first.
A joint with tight fit up is easier to start & fuse. A less tight fit might need filler to join the two pieces in the start. Begin by giving plenty of heat to liquify each piece. a jab of the pedal usually fuses them.

The puddle begins. Focus a very short arc on the leading edge of the puddle. In steel, you can try lay wire, or dabbing. The concept is chill the liquid puddle by melting filler. Keep a balance of hot enough to flow wet, not so hot it falls away.

[kraythax]

Sshorter arc length was the key, and a pointed (not blunted) tungsten. Worked like a charm. However, I am finding my butt joint and flat mitre joint welds are very flat and I actually kind of like it because it reduces post welding cleanup which is important as I want to weld a table. Is it a bad thing to have flat welds?

[Willie B]

No particular value in a big Keloid scar. Most cases flat is OK.

[kraythax]

No particular value in a big Keloid scar. Most cases flat is OK.

Thanks. I was trying to upload a picture to show you but it wont let me for some reason.

[Willie B]

Thanks. I was trying to upload a picture to show you but it wont let me for some reason.

I send a picture from my phone to Email.
I open it in Email, save it to desktop.
I give it a name when I save it.




I click on the picture framed tree Third from right above. I type the name.
Click on the name.
Open.
It comes up.
Upload file.

[ronsii]

I send a picture from my phone to Email.
I open it in Email, save it to desktop.
I give it a name when I save it.




I click on the picture framed tree Third from right above. I type the name.
Click on the name.
Open.
It comes up.
Upload file.

Framed tree???? Oh!, wudaya know: there is a tree in there

[kraythax]

Cool, thanks. Anyway we can call this thread solved