Reply to Thread

Re: TIG: Puddle cooling causing bad weld

Originally Posted by mpl_metal_art

Thank you. Will push up to about 24-25? It seemed like the weld with the FUPA looked better, but really want to get better at a #6 first. Will take all advice above and keep practicing.

Yes.

My formula for gas flow is 2 times cup size, to 3 times cup size. So a #12 cup would be 24 to 36 cfh, with a median of 30 cfh. I always target the median and go up for outside corners, and can go down for inside corners. This formula works for any size cup.

Re: TIG: Puddle cooling causing bad weld

Originally Posted by shovelon

20 cfh is a little lite for a #12 cup.

Thank you. Will push up to about 24-25? It seemed like the weld with the FUPA looked better, but really want to get better at a #6 first. Will take all advice above and keep practicing.

Re: TIG: Puddle cooling causing bad weld

Originally Posted by snoopdogg

Practice, just started tig myself, and see improvements every session. Using a suare and soapstone on coupons helped me with the straight lines. Are you running your machine on 220v?

Yes, running on 220V.

Re: TIG: Puddle cooling causing bad weld

Thank you Oscar, very helpful feedback. Will keep practicing.

Re: TIG: Puddle cooling causing bad weld

Originally Posted by G-ManBart

It looks like FUPA 12 is what he's got listed.

20 cfh is a little lite for a #12 cup.

Re: TIG: Puddle cooling causing bad weld

Originally Posted by shovelon

So what size fupa cup are you pushing 20cfh argon through?

It looks like FUPA 12 is what he's got listed.

Re: TIG: Puddle cooling causing bad weld

The second image shows your weld is funky because it had been welded on prior and toasted. Also your travel speed and deposition rate are off. I like to establish a puddle, cram in the rod, and jam forward. Mine has more of a crown on the topside, and much less melt through on the backside, with much less saturated heat. Not that I am saying what you are doing won't work, but time is money, and speed is workmanship. It is really hard to drive a straight line on the freeway if you are cruising at 2 mph.

So what size fupa cup are you pushing 20cfh argon through?

Re: TIG: Puddle cooling causing bad weld

Practice, just started tig myself, and see improvements every session. Using a suare and soapstone on coupons helped me with the straight lines. Are you running your machine on 220v?

Re: TIG: Puddle cooling causing bad weld

The OP might try practicing on some thicker metal, until you get confident then try the thin stuff.

Re: TIG: Puddle cooling causing bad weld

No magic secret other than keep practicing. Remember the pedal is there for you to control the amperage that you need, just like you wouldn't go wide open throttle in your vehicle all the time. The beads are heavily oxidized, but you will get better as you learn to manage your travel speed, arc length, torch angle. There's also only so much you can do on small coupons. I would ditch the 3/32" filler as it takes much more heat to melt it compared to 1/16" filler. If they get saturated with heat, nothing will prevent oxidation as the bead will not be able to cool off before the argon coverage disappears. No orange-dust-of-death so that is a real good sign. So technically nothing wrong with your welds looking terrible; you're barely learning how to TIG weld which is a months-to-years long learning curve assuming you keep practicing on a consistent basis. There is no way you'll be making 4-5" long welds that look flawless when you're just beginning, so get that out of your head and learn to create/observe/manipulate the puddle at first. Watch some videos from Jody @ weldingtipsandtricks on Youtube and pay close attention, as he obviously has real good technique. if you keep practicing consistently, in 1 year you'll easily be able to look back and reflect on the minor subtleties that make good TIG welds. Also even on cold-rolled, I would still flap disc it to remove any and all surface oxides.

Re: TIG: Puddle cooling causing bad weld

Thank you all for the great feedback, I will turn down the gas, increase amps, and melt the puddle in 2-3 secs. I put my specs and associated image below. Welcome any feedback how to improve.

Machine: Everlast Powertig 185DV.

IMG1:
- 130A, full pedal.
- 15 CFH
- 3/32" 70S-2 filler. No acetone.
- 3/32" tungsten
- 1/8" cold rolled coupon, wire brushed but not flap disc'd to "shinnier" metal. No acetone.
- 3/16" stickout.
- #6 gas lens.

Attachment 1727319

IMG2
- FUPA12 cup
- 130A, 3/4 pedal.
- 20 CFH
- 3/32" tungsten
- 3/32" 70S-2 filler on bottom, 1/16" stainless ER308L filler on top. No acetone.
- 1/16" cold rolled coupon. Wire brushed. No acetone.

Attachment 1727320

Re: TIG: Puddle cooling causing bad weld

I'm not clear why standard hardware is sold. A gas lens is no more complex than the aerator on your kitchen faucet. Just a bigger delivery hole with a few layers of screen to diffuse gas. I'd have said you are using too much argon. Try a gas lens, #6 cup, and 15 CFH. I rarely use bigger filler than 1/16 for steel. It might be different in open root beveled joint geometry.

I think other factors are bigger than filler size, but you'll like 1/16.

Re: TIG: Puddle cooling causing bad weld

If your welding on "mild steel" try cleaning the mill scale off. Somes times that junk mixes in the weld pool and looks like crap.

Re: TIG: Puddle cooling causing bad weld

Originally Posted by mpl_metal_art

Hello, running about 70-90 amps on 1/8" to 1/4" metal. I'm using 3/32" ER70S-2 filler and about 20-25 CFM. My welds look terrible. Is it possible the 3/32" filler is too big and it's cooling the puddle and I should switch to 1/16" filler?

Don't know what size cup you are using but pushing 25cfh argon through a small standard nozzle spells trouble. Too much turbulence. I personally don't get on with standard cups and collet bodies unless they are extended cups to let the turbulence settle some before exiting. I like gas lens setups.

The other thing is a cheap chinese soft copper collet may be crushed allowing the backcap to block the gas port in your torch. To check this tighten the backcap, then unscrew the cup and collet body and remove the collet and tungsten. Look into the open end to see if the backcap is over the hole. If good, reassemble then remove the backcap, collet, and tungsten and look into the backside to see if the collet body is choking the hole. Cheap online parts are hit and miss as far as tolerance.

For .125" to .250" material I set 150% or more in amps and float the pedal. So I would be cranking up the amps to 200 or more if you have it.

Re: TIG: Puddle cooling causing bad weld

Why is your gas pressure so high? Am I missing something? What material? Apparently I missed that also.

Re: TIG: Puddle cooling causing bad weld

To amplify what Oscar said, try to apply enough heat fast enough that you get a puddle melted within 2-3 seconds. It might be counter-intuitive at first, but this actually puts less total heat into your workpiece and will thus result in less distortion/warping in the long run, too.

These principles will be even more important and apparent when you move on to welding aluminum, since aluminum's thermal conductivity "wicks away" heat even faster than steel.

It's like riding a motorcycle: Whenever in doubt, give it more gas!

Re: TIG: Puddle cooling causing bad weld

Oscar covered the amperage well, so that will get you in the right ballpark. What also happens when you run the amperage too low you wind up putting more heat into the piece because it simply takes longer, and that makes it harder for the puddle to freeze quickly when you add filler.

One thing not mentioned is how you're preparing the metal to be welded. It has to be clean, shiny metal with no millscale or anything else...like a mirror is ideal, but at least down to clean, white metal, then wipe it down with acetone before welding. It's also not a bad idea to wipe down the filler rod with acetone as well.

It seems like your gas flow is too high as well. Take the cup size you're using and double it to get the ballpark flow rate in CFH. If the flow is too high it can cause turbulence, poor gas coverage and porosity. Also, make sure you don't have any source of a breeze like the output of the cooling fan from the machine pointed anywhere near the work...that can cause a lack of shielding gas as well.

Re: TIG: Puddle cooling causing bad weld

Thank you Oscar. Great feedback. Will practice this weekend, record specific information, and post the pics. Appreciate your time.

Re: TIG: Puddle cooling causing bad weld

Thank you for the welcome and feedback, much appreciated.

Re: TIG: Puddle cooling causing bad weld

Wayyyy to low amperage for both scenarios. Try 100-120A for 1/8", and 200-250A for 1/4". Obviously it all depends on joint geometry and size/orientation/direction, but otherwise you're trying to melt metal with snow. 3/32" filler is ok for 1/4" but just like with amperage, it depends on joint geometry and size/orientation/direction. You need to keep experimenting to see what works better for you. For less than 1/4", 1/16" will generally work better but again depends on joint geometry and size/orientation/direction. As you keep practicing, all these details will hopefully work themselves out for you and it will be second nature; you'll hardly need to think about it. So the 'bad welds' are most likely just because you haven't learned how to weld yet (usually it's a combination of improper things). Practice, post specific information (not a super wide range of what you tried over the course of 2 weeks, but actual discrete, individual info for EACH trial), and post the pictures. It will all make sense to others who can piece together the information for you.

Re: TIG: Puddle cooling causing bad weld

In welding, anything is possible. But what you really need to do to get some solid help is post good photos of some of those "terrible" looking welds. What that will do is cause some of the viewers here to feel ashamed of themselves that they still can't weld that good, and will provide an extreme feeling of smugness, joy, mirth, and gloating to the rest that they are so much more advanced.
But,all jokes aside, trying the 1/16 wire is an easy matter. Then you will know. And welcome to the forum.
There is also a chance that you just haven't learned how to tig weld, which can be remedied by practice and a willingness to apply what you learn.
All the best from the villageblacksmith.

TIG: Puddle cooling causing bad weld

Hello, running about 70-90 amps on 1/8" to 1/4" metal. I'm using 3/32" ER70S-2 filler and about 20-25 CFM. My welds look terrible. Is it possible the 3/32" filler is too big and it's cooling the puddle and I should switch to 1/16" filler?