Having trouble with 4130 tubing

[hunter59]

I'm having a terrible time with welding 4130 tubing, I have a Dynasty 350, I am welding 1.25 .095 wall 4130, I have cleaned it with a die grinder with a red scotchbrite pad, then wiped them with acetone. I am using about 90-100 amps, 3/32 2% with ER70S6 1/16 rod, 15 on the argon...........every weld is too hot, very gray, I couldn't get a shine out of a weld if you paid me. What the heck am I doing wrong.........very frustrated.

[sdwelder]

Having trouble with 4130 tubing

Maybe try either stainless filler or ER-80s. Also maybe turn the machine down a bit if you feel its to hot.

[gouch95]

First is your fit up nice and tight? next what type of point on your tungsten? Then my next suggestion is turn it up a little and weld fast. and I only use 80-D2

[hunter59]

I have not tried the ER80 yet, my fit up on most of the joints is perfect(milled with an endmill) my point on my tungsten is very sharp......I will try to get some pictures today, of the welds.

[zank]

Gas lens or regular collet body? What size cup? Are you keeping your post flow over the bead?

[gnforge]

Having trouble with 4130 tubing

It's your filler, that's normal for 70S6. Match your filler with the 4130.

[zank]

Only use 4130 filler if you are going to heat treat the finished weldment.

[hunter59]

I have been using a gas lens but went to small cup to access small areas, didn't make any difference on the outcome, and yes I am holding the cup over the weld and slowly backing off the amperage. I am not going to heat treat the part. I really wonder if it is something in my technique. I will get pictures..........

[turbo38t]

Try the ER80s2 ....it won't really affect the color but it's what most people use. Try gas at 10-12 cfh.....a larger cup helps....if you are running to hot you can add filler faster to cool it quicker....make sure you have the post flow set for atleast 6-8 seconds and hold it after you're done....I used 2% lanthanated....this was with a Sync 250....1/16" tungsten. I had tubing in diameters from 3/16" OD up to 1" ID and wall thickness from .029-.625......the millscale will wreck havoc on you....make sure it's CLEAN CLEAN.

I have been using a gas lens but went to small cup to access small areas, didn't make any difference on the outcome, and yes I am holding the cup over the weld and slowly backing off the amperage. I am not going to heat treat the part. I really wonder if it is something in my technique. I will get pictures..........

[Portable Welder]

I've switched to S-2 verses S-6, However I dont think thats your problem,
Turbo 38 was thinking the same thing as me which is use a bigger cup, If you use a small cup and try to turn up your cfm to compensater the turbulance will pull in outside air which is likely contaminating your weld.

[hunter59]

Now that sound like a plan, more and more I'm thinking it is air contamination.

[Portable Welder]

Hey, And your welcome by the way.

[zank]

pictures would still help.

[hunter59]

I want to thank you all for the advice, as it turns out I was not flowing enough argon. Simple as that......I had been up and down on the flow meter, but apparently not high enough. I am flowing 25 on the meter and all is well. Shiny welds and can control the speed no problem. Again thank you all.