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Gray welds. New to tig.
Posted: Mon Aug 10, 2020 1:17 pm
by lyrikz74
I just started tig welding. I have been googling, and youtubing myself to death. I have a primeweld 225. IM using 304 stainless, 308l filler, cleaning everything. Gas is at 25cfm. #5 cup. ALL of my welds are grey, dull ass crusty gray. On one or two occasion i can get a clear weld. I have ran through EVERY single temperature setting. From what i have learned, its like the shielding gas or the cup isnt big enough? If i do dabs and stop, i get some shiney. Attached pics.
I have not checked to see if i have an air leak anywhere, i will check that tonight. Im just looking for any direction. Whats crazy is i will lay down a weld and get a bit of clear in it, then copy the EXACT same setup and it will be that gross crusty ass gray. My guess is to small of a cup? There is NO filler in these welds. When i did add filler, nothing changed. You see the crap weld has the 3 shiny dots? that was just a test pulse, then i used the same settings and got the gray mess right next to it.
Im open for any help. Id be willing to pay someone at this point. I would like to take a class i just dont have the time right now.
Re: Gray welds. New to tig.
Posted: Mon Aug 10, 2020 5:17 pm
by Oscar
A #5 cup with stainless is for the pro's. As a beginner, Give yourself an advantage with a #8 cup for better coverage. Remember that you have to move FAST to prevent heat soaking the part, and a short tight arc length also minimized un-necessary (and unwanted) extra heat. That's part of the reason you got 3 shiny dots FIRST when the part was cold, and then you likely tried to run a bead on a warm plate that could not dissipate heat as quickly, and there is your excessive oxidation. 1x-1.5x the tungsten diameter for arc length. BTW, 25 CF
H is like a typhoon for a #5, not sure which YouTube video told you to use that much
. #5 about 10-12 CFH, #6 about 10-16 CFH, #7 about 12-18 CFH, #8 about 14-22 CFH are my preferences.
IMO,
Rule #1: don't run beads on a SS part that is not room temp. You're setting yourself up for failure as a beginner.
#2. Minimize stickout and arc length.
#3. Larger cup like a #8.
Re: Gray welds. New to tig.
Posted: Mon Aug 10, 2020 5:49 pm
by LtBadd
Oscar wrote:
Rule #1: don't run beads on a SS part that is not room temp. You're setting yourself up for failure as a beginner.
#2. Minimize stickout and arc length.
#3. Larger cup like a #8.
#2 And the torch angle should be 0* to 15* off vertical
#3 Or a gas lens with a #8 cup
Re: Gray welds. New to tig.
Posted: Mon Aug 10, 2020 5:52 pm
by Oscar
LtBadd wrote:Oscar wrote:
Rule #1: don't run beads on a SS part that is not room temp. You're setting yourself up for failure as a beginner.
#2. Minimize stickout and arc length.
#3. Larger cup like a #8.
#2 And the torch angle should be 0* to 15* off vertical
#3 Or a gas lens with a #8 cup
Yes absolutely.
#3 or a
QUALITY gas lens with a #8 cup.
Cheap gas lens have cause enough troubles for me and others here recently, only to find out going back to standard consumables fixed oxidation issues. Live and learn.
Re: Gray welds. New to tig.
Posted: Mon Aug 10, 2020 8:00 pm
by cj737
Aside from switching to a gas lens and at least a #8 cup (I use a #12 for stainless and 25CFM) you don't mention the thickness of the material or amperage you're welding?
Stainless soaks up heat diabolically quickly. One short weld and the piece will be very hot. If you weld nearby, that weld will be over-heated and cooked (gray, dingy appearance). You need to let stainless cool between welds. You can also clamp your practice piece to a thick piece of aluminum to help draw some heat out, but you still need to monitor and abide the heat soak.
I weld most stainless at 80% amps of the thickness (.125 material I run 90-105 amps depending upon shape and joint). With pulse, I use 105 amps, 50% on time, 25% background, 1.2 PPS. I like a slow methodically shot of heat, then a cooling period. I also run a 2 second reflow, and at least a full 12-15 seconds of post flow. Keep the cup still over the weld while running your post flow, or backtrack a bit.