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Stainless greying bead

Posted: Mon Apr 06, 2020 5:25 am
by Cabbage
Hi all, I'm new here and to welding, so go easy please :)

I'm trying to lay down some practice welds on a 1.5mm bit of stainless. My welds consistently look like they've oxidised (I think...). I'd like some help on what's going wrong and why I can't lay down a shiny weld.

Welder info:
  • Torch WP9 - 5 cup and 5 cup with gas lens. 1.6mm sharpened tungsten (both red and white tip)
  • Gas - Pure Argon - and I've tried between 5LPM and 10LPM
  • DC - 40-45amps, No pulse, pre flow 0.5sec, post flow 8 sec
  • 1mm and 1.6mm filler rod (316L and A15),
  • welding stainless box section that has been scotchbrited and acetoned so I believe it's clean?
My thoughts were it could be:
  • too slow travel speed and therefore too much heat in the weld
  • not enough gas flow
  • too much gas flow
  • air leaking into the system
  • Torch not upright enough
  • contaminated tungsten
  • Too much torch height
  • Too much stickout
I've done my best to eliminate all of the above or try variations of things to see what helps. I am new to this so it is probably something very fundamental I'm getting wrong. Pics attached, please note in a couple of welds I've dipped and carried on, but all my welds are consistently crappy looking, regardless of whether I've just cleaned the tungsten. Also on some of them I really raced through to test whether I was being too slow, and I don't have the skills to lay down anything neat yet, so ignore the fact it looks like a 4 year old laid those beads haha. And apologies but I can't remember which photos had which settings, I think the 20200406_085547.jpg pic had the gas flow dropped to 5LPM. I'd appreciate any feedback anyone has. Thanks.
20200406_085504.jpg
20200406_085504.jpg (60.58 KiB) Viewed 1381 times
20200406_085521.jpg
20200406_085521.jpg (71.71 KiB) Viewed 1381 times
20200406_085547.jpg
20200406_085547.jpg (68.14 KiB) Viewed 1381 times

Re: Stainless greying bead

Posted: Mon Apr 06, 2020 10:26 pm
by Poland308
Incorrect gas flow. Either to little, wind or fan blowing it away, or a leak on your torch drawing in air.

Re: Stainless greying bead

Posted: Mon Apr 06, 2020 10:41 pm
by tweake
Cabbage wrote:Hi all, I'm new here and to welding, so go easy please :)

I'm trying to lay down some practice welds on a 1.5mm bit of stainless. My welds consistently look like they've oxidised (I think...). I'd like some help on what's going wrong and why I can't lay down a shiny weld.

Welder info:
  • Torch WP9 - 5 cup and 5 cup with gas lens. 1.6mm sharpened tungsten (both red and white tip)
  • Gas - Pure Argon - and I've tried between 5LPM and 10LPM
  • DC - 40-45amps, No pulse, pre flow 0.5sec, post flow 8 sec
  • 1mm and 1.6mm filler rod (316L and A15),
  • welding stainless box section that has been scotchbrited and acetoned so I believe it's clean?
cup is way to small.
i would use an 8. fairly typical size. stainless loves argon.
amps sounds close enough. but you may want to look at more amps and increase travel speed. travel speed is king with stainless.

Re: Stainless greying bead

Posted: Tue Apr 07, 2020 2:52 am
by Cabbage
Thanks guys, biggest cup I have to hand is a 7, so I'll try that first and see if it improves. Failing that I'll work through the other suggestions!

Re: Stainless greying bead

Posted: Tue Apr 07, 2020 7:19 am
by Oscar
Cabbage wrote:Thanks guys, biggest cup I have to hand is a 7, so I'll try that first and see if it improves. Failing that I'll work through the other suggestions!
#7 is way too small. Think more like #10-16 gas lens. Yup. Thin sheet will get overheated quick, and you need to keep the beads short enough that the beginning of the bead does not escape the argon shield. If it does, that's why its oxidizing. Another thing that will help tremendously is active heat-sinking via chill-bars of some kind, whether they be copper or aluminum.

Re: Stainless greying bead

Posted: Tue Apr 07, 2020 8:09 am
by Coldman
All of the above.

Anything under 2mm in staino I pulse. It takes your weld finish to another level. If you have it use it. That's what it's for.

Re: Stainless greying bead

Posted: Tue Apr 07, 2020 9:04 am
by Cabbage
Thanks for the advice all. I'll try it out.

Re: Stainless greying bead

Posted: Sun Apr 12, 2020 1:50 pm
by Spartan
The Furick #12 cup (I use the ceramic) is an absolute champion for welding stainless. I run it with about 25 CFH and about 9/16 - 5/8" stick out unless I happen to need a longer stick out. Love it. Jody sells them on weldmonger, and you can also buy cups directly from Furick.

Re: Stainless greying bead

Posted: Sun Apr 12, 2020 5:57 pm
by bap_
You should be OK with a #7 or #8 gas lens, but bigger would be better. Once you go above a #8 I find that you NEED the extra diffuser.

For example going from a #8 to #10 CK pink cup, I find that the #10 is not as good a cup and I get better results with a #8. If I use a #10 or #12 furick that is a game changer with that extra diffuser.

You should be between 7 and 10 LPM with a #7/#8

Run a few beads without filler at different travel speeds you should be able to get a shiny bead, otherwise you likely have something wrong.

Re: Stainless greying bead

Posted: Sun Apr 12, 2020 7:37 pm
by Simclardy
Some guys like to use a standard #5
But i use a furick #12 and a trailer on thin stuff.
You have a gas coverage issue.
I would use at least 1.5 pre flow and and try 12s post for now.
Try to do one dab without traveling. This eliminates some of the"operator error".
It should look nice and shiny. Then you will start to weld and notice your last little bit looks good and the rest not so much. At this point you learn to move quicker and increase your gas coverage, hence the#12
Cheers

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Re: Stainless greying bead

Posted: Sun Apr 12, 2020 9:29 pm
by TraditionalToolworks
I don't know, it seems these new welding cups are getting out of control... :lol:
welding cups are getting out of control
welding cups are getting out of control
welding-cups-getting-out-of-control.png (581.03 KiB) Viewed 1154 times

Re: Stainless greying bead

Posted: Sun Apr 12, 2020 9:58 pm
by Simclardy
Lol

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Re: Stainless greying bead

Posted: Mon Apr 13, 2020 6:23 am
by LtBadd
:lol: :lol: :lol: