93h2beg

Hey, I know this is far from pretty and probably good.

the tube is thin stainless, unknown type, i used a 3/32 tungsten, with a tiny filler rod.

amps were around 70. Looks to me like to much heat and not enough filler.

should I drop to the next size down tungten and maybe the next size up filler?

seelback

what machine are you using? whats the thickness of the ss your welding?

93h2beg

It' a Miller squarewave 200.
the thickness is 14 ga, or close to that

chopnweld

I would use 1/16 tungsten with a 1/16 filler rod. If you have the capabilities I would back purge as well.

93h2beg

That is what i bought on Monday- no capability to back purge

thanks

2fast4u831

It looks like you are moving too slow and or gas shielding is a problem as well by the color you are getting.

Caoboy

Way too slow on your travel speed and too high of an amperage. Example: I fused shut some pipe joints, they were .065". used 35 amps, full pedal, 35cfh with a #8 gas lens. (20 torch)

You're at .078", you could sit pretty at 45-50 amps with the right travel speed. Do 1/4 of the pipe, let it cool for a few seconds/minutes, then do the next 1/4, starting behind your first weld, and running into it.

If your fitup is good, you can fuse it and get no burn-through. If you need filler rod, you want just enough to seal the joint. You don't want to push too much without being able to back purge, you'll get burn-through and sugaring. Go .045 to 1/16th max rod (I prefer smaller filler rod with SS, I'd stick with .045) 3/32 tungsten is fine. How are you grinding your tungsten? The angle makes a difference.

The color of your weld will tell you if your travel speed is good enough for the amperage you're using.

No color(clear/mirror) to gold color is what you want to shoot for. If it's blue it's too fast/not enough gas coverage/post flow. Grey, like yours, means the weld has carbon precipitated, basically turning into mild steel, in the weld.


Nothing replaces hood time though, that's for sure. Maybe get a scrap piece of pipe and just run stringers on it to get a feel for what speed/amperage/feed rate and gas flow rate is best for you.

93h2beg

Thanks for the feedback!

that is really what I was looking for. Yes, more hood time is needed for sure.

I grind my tungsten on the good old angle grinder with a dedicated disc for each type of metal I am welding. Trying to eliminate cross contamination.

as for the point I am grinding, I have been trying several, short blunt, longer sharper, 45* angle... seems to me I may also be too dang close when I weld.... yes I have to grind the tungsten ALOT.

I don' have any other scrap as pipe, tons of coupons from work, but no thin gauge pipe.


is 35cfh a bit high? I thoight I wanted to be around 15-20?!?!?!? I' o the good old standard #7

Caoboy

If you have a regular collet and cup, higher cfh won't help. Gas lens has a diffuser that turns the tornado winds into a nice fog, which means you can pump up the cfh and get more coverage across your part.


For tungsten angles:
https://www.instagram.com/p/BcnDIcbAFrQ/

That's a good reference. That dude is a welding machine.

chopnweld

Gas pressure on a standard torch setup shouldn't need to be more than 25 PSI. Running too high will cause gas turbulence where the gas hits the work piece and causes turbulence pulling in atmosphere and can contaminate the weld. If you have a gas lens set up you should run LESS gas pressure, because the more uniform stream of gas provides better coverage allowing you to run lower gas pressures and save on gas consumption. With my gas lens I run 15 PSI.

just an example if you don't already know, a gas lens acts the same way as the screen in your kitchen faucet. Take out the screen and turn on the water, the water comes out irregular and not uniform. With the screen in, the water comes out in a uniform even flow. Same thing is happening with the gas. That's why you can get the same coverage with less gas pressure and you can also run a longer tungsten stick out.

Caoboy

Interesting. I was taught to crank it up with a gas lens. I'll lower my cfh and see what the results are!

chopnweld

yea, if all things are equal and your stick out and arc length are the same as on a standard nozzle setup then you should be able to run lower gas pressures. If you're running a monster cup with a gas lens with a 1.5-2" stick out I'd stay at my standard 25 psi pressure.

https://www.millerwelds.com/resource...w-applications

seelback

3/32 tungsten is good. your travel speed is to slow, your amperage is to high, .035-.045 filler rod should be good. measure the exact thickness of your material if you can, for example if your material is .060 then you should run 2/3 of your material thickness in amperage for stainless which would be 40 amps max and just rely foot pedal. i would get a #12 glsfab cup and run 20-25cfh until you get a good handle on welding stainless. I started out using a jumbo cup cause it helped me when learning and then i was able to step down to a #8 gas lens with no issues of bad colors, the bigger cup will help you get away a little more with travel speed a little slow or amperage a little high. as far as the #8 gas lens, i run 15-20cfh with no issues, 35cfh on #8 gas lens is screaming high and you are using up too much gas.

93h2beg

No pics of it, but we just got a Lincoln 350MP with push pull gun at work to day for production type aluminum welding. HOLY COW! It says it can only do 5/16" aluminum, so naturally I tried it out on 1/2" and was able to get about 70% depth (3/8") in penetration on the cut test. dang amazing machine. Haven't not done any more SS, will do tomorrow morning though.

850Fabrication

I have found that cheap polished chinese tubing to require less amperage than the standard mandrel bends and dont react well to running too hot. the pool likes to wander if you run too hot

Caoboy

"Other people's gas" setting