Cup Size???

rahtreelimbs · Tue Mar 28, 2017 1:42 pm

Can using too big of a cup.....say 3/4" with a gas lens.....compared to a 1/2.......with a gas lens......be detrimental to the weld?

Rick_H · Tue Mar 28, 2017 2:24 pm

rahtreelimbs wrote:Can using too big of a cup.....say 3/4" with a gas lens.....compared to a 1/2.......with a gas lens......be detrimental to the weld?

In most cases I say NO, just an increase in coverage or wasted Argon.

dirtmidget33 · Tue Mar 28, 2017 3:58 pm

Larger cup not gonna hurt anything just creates larger inert atomsphere around weld. It can help give you better color on welds do to coverage staying on area until it cools longer as you move. However larger cups require more flow and if weld doesn't really need the extra coverage it's just a waste of argon.

noddybrian · Tue Mar 28, 2017 4:00 pm

I can't think of any situation a bigger cup size is'nt better !

kiwi2wheels · Tue Mar 28, 2017 4:15 pm

I had an instance where I was plugging some holes in an aluminum rad tank with some 1.2 x 18mm diam discs into the hole from a 20mm tube, which had been hit with a 90 deg counter sink to locate the disc.

Using a #6 cup with a gas lens was a PITA, always burning the disc back, and this was being done on a bench , so there was no access problem, re torch angle.

Changed to a plain # 5 cup, three tacks and weld, finish. I'd sure like to understand why !

Farmwelding · Tue Mar 28, 2017 4:29 pm

noddybrian wrote:I can't think of any situation a bigger cup size is'nt better !

Never really hurts. Only time is if it had to be small to fit somewhere. Really, you can't ever get enough gas coverage for the most part. Too much can cause problems of blowing out the weld but...

noddybrian · Tue Mar 28, 2017 4:39 pm

Were we still talking about welding - sorry - my bad - mind must have wondered !

exnailpounder · Tue Mar 28, 2017 4:50 pm

noddybrian wrote:Were we still talking about welding - sorry - my bad - mind must have wondered !

You too?

exnailpounder · Tue Mar 28, 2017 4:53 pm

Jody suggests that a smaller standard collet body and cup can work better for Aluminum. Has anyone ever tried it? Once I put on a gas lens, I never took it off but I just watched one of his vids and he says it and so does Roy Crumrine.

noddybrian · Tue Mar 28, 2017 5:16 pm

I too tended to leave a gas lens on with a 7 or 8 for everything but had to switch back to a standard length 5 for access on an aluminum casting - cannot explain how but it creates way more etch zone / cleaning action for the same AC balance - after realizing this I found you could run less cleaning on the balance & give the tungsten an easier life - also when crap boils out / explodes it does'nt ruin anything - just scrape the ceramic clean if it builds up - not like gas lens mesh so I now use standard collet body for aluminum - found this out by accident a while back - then saw Jody recommend it so if it's good enough for him it must be right.

GreinTime · Tue Mar 28, 2017 11:09 pm

kiwi2wheels wrote:I had an instance where I was plugging some holes in an aluminum rad tank with some 1.2 x 18mm diam discs into the hole from a 20mm tube, which had been hit with a 90 deg counter sink to locate the disc.

Using a #6 cup with a gas lens was a PITA, always burning the disc back, and this was being done on a bench , so there was no access problem, re torch angle.

Changed to a plain # 5 cup, three tacks and weld, finish. I'd sure like to understand why !

AC only cleans where there is argon coverage, so better coverage over a wider area leads to a wider weld with a wider cleaning zone for a given amperage.

Sent from my VS995 using Tapatalk

noddybrian · Wed Mar 29, 2017 3:27 am

That makes perfect sense in theory but I seem to get a wider cleaning band from a regular collet #5 than a #7 or #8 gas lens for the same balance setting which makes no sense at all - I can actually go slightly more EN & get the same etch zone using a standard #5 so that's what I use now - I don't understand why though - only swapped out due to contamination originally - guess when you find something that works stick with it even if it defies logic / instinct.

cj737 · Wed Mar 29, 2017 7:38 am

exnailpounder wrote:Jody suggests that a smaller standard collet body and cup can work better for Aluminum. Has anyone ever tried it? Once I put on a gas lens, I never took it off but I just watched one of his vids and he says it and so does Roy Crumrine.

I use an #8 Pyrex and gas lens mostly, but swap to a collet body and #5 for tight spaces or small pieces/thin pieces. The #5 is small enough that gas flow doesn't really see the turbulence of a larger diameter cup so the gas lens isn't as differentiated. My input.

Poland308 · Wed Mar 29, 2017 11:00 am

I use standard alumina cups size 5-7 for almost 99% of stuff at home and at work. I have gas lens cups and standard ones up to about 12 but don't use them much.

kiwi2wheels · Wed Mar 29, 2017 12:49 pm

GreinTime wrote:
kiwi2wheels wrote:I had an instance where I was plugging some holes in an aluminum rad tank with some 1.2 x 18mm diam discs into the hole from a 20mm tube, which had been hit with a 90 deg counter sink to locate the disc.

Using a #6 cup with a gas lens was a PITA, always burning the disc back, and this was being done on a bench , so there was no access problem, re torch angle.

Changed to a plain # 5 cup, three tacks and weld, finish. I'd sure like to understand why !
AC only cleans where there is argon coverage, so better coverage over a wider area leads to a wider weld with a wider cleaning zone for a given amperage.

Sent from my VS995 using Tapatalk

It was near impossible to make a run between the tacks with the gas lens set up. The arc would always migrate to the disc, like welding on steel too close to a magnet. I was more or less making a series of tacks and then pulsing over them.

It was the first inverter machine I'd used, but the other alu jobs (extrusions, castings, etc) hadn't been a problem with gas lens.