Preflow on MIG

I know. I know. That's not really a thing. Still I was welding up some T-handles on thread rod for some tools yesterday. I noticed that for just a
fraction of a second at the beginning of the first weld on a part the weld would be unstable and throw a little spatter. Then it would stabilize and weld perfectly. All I can attribute it to is that it took a tiny fraction of a second for gas to reach the nozzle. Still if the gas solenoid was triggered half a second before the wire was electrified I can't help but think the start would be better. When I shut the welder off I happened to notice my CFH gage was showing a little under 20, and the welder recommends 30 for everything on the flip chart. The other day welding hinges on some thin wall rectangular tube 20 seemed to be fine. Maybe it was just the shape of the t-bolt? Maybe the 30CFH setting hits the nozzle quicker? I have the regulator style flow gages.
P.S. Referring back to my issues with this welder and the bad gas diffuses... I use MIG welding as the fast fall back tool for a lot of things I'd often find other means for in the past. Even my crappy welds look better. I haven't used my little flux core only machine since, although I still would outdoors.
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On Sun, 3 Feb 2019 08:49:59 -0700

Higher flow rates can cause turbulence and possible bad coverage. When I was doing a lot of welding for my Dad on a couple products. I would run 8 CFH with 75/25 gas. No reason to run 30 when 8 would make perfectly good welds. My favorite nozzle is slightly reduced/tapered at the tip. Looks a lot like this:
(Amazon.com product link shortened)
I couldn't get away with running 8 using big stove pipe nozzles though. Never needed one that large unless trying to weld 3/8 in a single pass which has its own set of problems...
Lighting up, starting out is always troublesome. You might want to try lighting up a 1/4 to 1/2 inch from where you want to start and then rapidly back up to that point once your arc is established. Picked this tip up from watching Jody's videos and works well. Providing I remember to do it, don't weld that often anymore...
--
Leon Fisk
Grand Rapids MI
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On Sun, 3 Feb 2019 13:05:33 -0400

Dang! Thinking about this later on and I'm sure that should have been 12 CFH and not 8. So anywhere you see 8 just pretend it is really 12 okay :)
A lot depends on what you're welding too. Laying into a corner filet or inside some small area will take a lot less gas flow than something flat, vertical, on-edge... you get the idea. Argon is heavier than air and will tend to settle and fill contained areas...
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Leon Fisk
Grand Rapids MI
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"Leon Fisk" wrote in message wrote:

Dang! Thinking about this later on and I'm sure that should have been 12 CFH and not 8. So anywhere you see 8 just pretend it is really 12 okay :)
A lot depends on what you're welding too. Laying into a corner filet or inside some small area will take a lot less gas flow than something flat, vertical, on-edge... you get the idea. Argon is heavier than air and will tend to settle and fill contained areas...
**************
I'm trying to spend less time looking for fault on-line, but I thought 8 CFH sounded awfully hopeful.
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On Mon, 4 Feb 2019 13:18:42 -0700
<snip>

Sometimes I use to run that low BUT... it had to do with what I was welding. It was inside maybe a 3 inch ID tube that was about 3 inches long standing upright. Needed to weld a pressed in plug to the bottom. You really don't need much gas because there is nowhere for it to go other than up and out of the piece. I think I still have some of those parts around if you can't visualize this. When you weld say 50+ parts like this for an hour or two that is a lot of wasted gas if you left it set at 20 CFH...
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Leon Fisk
Grand Rapids MI
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