Tig welding tips, questions, equipment, applications, instructions, techniques, tig welding machines, troubleshooting tig welding process
nelson
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HI folks.
I have the welder listed below. It came with a flowmeter. I was wondering if the pressure is too high though.
When I start a weld there's a big gush. I don't know if it's adjustable. I could put a regulator ahead of the flowmeter I guess. I don't know if this affects my Al but my steel looks fine.
I use the same tank for a microwelder. Big gush thru a little nozzle.
Stone knives and bearskins.....and a NEW EVERLAST 164SI !!!
That's my newly shared work welder.
At home I got a Power Tig 185 DV. Nice, but no plasma cutting... Nice tight arc after a second.
ignatz200
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I ran into exactly the same problem, went to talk with my local welding supply house tech to figure out what was going on and found the answer. :D

The problem is this: A flowmeter regulator works with a primary step-down diaphragm arrangement dropping the high pressure gas in the cylinder (2000 PSI) down to a stable, secondary working pressure, which in my flowmeter is something around 65 - 70 PSI.

When you adjust the valve on the flowmeter you are gating the argon gas flow. It starts at that secondary working pressure in the flowmeter, but drops down to a lower pressure after passing your adjustment needle valve on the way to the back of your welder (with it's own on-off solenoid valve).

But here's the part that's causing your problem. When you DON'T weld, the gas pressure in that section of gas tubing between your flowmeter and the back of your welder is slowly creeping up... until, yes, you guessed it, it is also at 70 PSI. So, now, when you trigger your torch, that first gust of gas coming out of your torch represents that little bit of built-up gas pressure. The longer that section of gas hose between the flowmeter and your welder, the more volume of argon gas at that higher pressure and the worse that first blast of argon out of your torch will be.

And now the answer.

What I did was purchase a second screw-on gas connector to fit the back of my welder at the gas inlet (kept the original in reserve).

Next, I turned a tiny bit of brass to fit inside the back of the that gas connector. In this tiny bit of brass is drilled a restrictor hole. That hole acts very much in the same way as the needle valve on your flowmeter, except that it isn't adjustable. I then soldered that bit of brass into the back of the gas connector, reattached the gas hose from the flowmeter and clamped it all up as normal. (see my wonky sketch, below)

The important bit is that the little bit of brass with that fine hole acts as a flow restrictor to buffer that first high-pressure rush of argon so that one doesn't get that 'gush' at the torch end.

For my purposes I used a #75 drill to make that hole. This allows me to push up to 16 CFH. Depending upon what flow you need for your welding you might want to use a slightly larger drill size. But be careful, since too large of a hole will totally defeat the purpose and eliminate the buffering effect.

Hope this helps.
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Pretty good idea, with another alternative being the GSS system from netwelding. I've considered it s8nce I also hate that gas surge.
Last edited by Oscar on Sat Jun 24, 2017 11:31 am, edited 1 time in total.
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mpete53
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I get the same rush of argon when I start but never thought of it as a problem since it becomes steady in a second. Am I missing something?
ignatz200
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mpete,

What you are missing is that the initial 'gush' is that tiny bit of argon gas trapped between the flowmeter and the welders own gas solenoid. When you trigger the torch, the welder's gas solenoid opens and that bit of 'higher pressure' trapped gas 'gushes' out. Of course, argon gas is also continuing to stream out of the flowmeter, but at a lesser rate, such that although the actual pressure within the flowmeter is high, the argon gas that has passed out of the flowmeter needle valve (headed out through the welder to the torch end) is now effectively at some greatly reduced pressure... and since the gas stream has already commenced, you no longer experience this continued flow as a 'gush', but rather as the actual delivery rate of argon gas that you dialed in with the flowmeter ball.
cherwolf
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What does that big knob in between two dials on gas regulator? Using ball flowmeter. Question arose when stumbled upon Gas savers, that prevent gas surge as mentioned above. And the guess was, that those dual dial flow regulators could have built-in gas savers?
MarkL
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Isn't the surge over before the preflow ends? I don't see why the surge matters if the arc hasn't started yet.
Lincoln Square Wave 200
Lincoln 225 AC/DC
Harris Oxy/Acetylene torch
nelson
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Hey thanks for the suggestion of that orifice. I think I'll try it, albeit a bit bigger.
There's no preflow on my unit when using the pedal. The gush happens when the arc starts.
There's no problem I've seen from this behaviour. Just wasteful i think. I use 80 cf tanks and I found out recently how much $. $32 for gas, $25 for delivery...I've stopped the deliveries. It's an hour trip to the LWS so a good excuse to get outside.
Stone knives and bearskins.....and a NEW EVERLAST 164SI !!!
That's my newly shared work welder.
At home I got a Power Tig 185 DV. Nice, but no plasma cutting... Nice tight arc after a second.
ignatz200
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Nelson,
You would be amazed at just how small a hole will let through the correct flow of gas. So, it's probably better to 'sneak up' on the size of the hole. Start out with something on the small side (I had chosen for a #75 drill bit). If you find that you aren't getting quite the gas flow you wanted, simply chuck a slightly larger drill in a hand pin vise and drill/ream out the hole. When you are getting the right kind of gas flow start behaviour with the maximum flow you might ever use, then stop.

I should also mention that I actually have a spare gas hose with the original, unrestricted fitting... just in case I ever choose to start doing some really heavy work that demands large gas cups. The type of work I do is pretty small and I get by with gas cups ranging from #4 up to #6, so I don't need quite that much argon flow most of the time.
cherwolf
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MarkL wrote:Isn't the surge over before the preflow ends? I don't see why the surge matters if the arc hasn't started yet.
Gas surge causes unnecessary gas waste, if you tack weld for example. Many starts and stops gush out your ca$. This is why I am interesting in gas savers, like Harris 25 IGG or alternatives.
MarkL
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nelson wrote: There's no preflow on my unit when using the pedal. The gush happens when the arc starts.
The manual for that machine indicates the preflow is factory set and not adjustable, but it doesn't say how long it lasts. It seems like 1/2 second is common on other machines I've seen.
There's no problem I've seen from this behaviour. Just wasteful i think. I use 80 cf tanks and I found out recently how much $. $32 for gas, $25 for delivery...I've stopped the deliveries. It's an hour trip to the LWS so a good excuse to get outside.
I was freaked out when I got my machine because the postflow is not adjustable, so I figured out what it was costing me. At 15cfh it costs me 4 cents/minute or .067 cents/second for argon. I get my 80cf tank filled for $13, so that's cheaper than what you're paying. Knowing the actual cost helped me stop thinking about it even though it still bugs me that I can't adjust it.
Lincoln Square Wave 200
Lincoln 225 AC/DC
Harris Oxy/Acetylene torch
Poland308
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Switch to a torch that has a built in gas valve. Then you control it even when the machine thinks it knows better. It's a built in needle valve at the torch so you could actually set it and leave it in place with some superglue to get the desired effect.
I have more questions than answers

Josh
nelson
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Point taken Ig.

When I'm doing an inside corner on Alum I usually have problems with the arc dancing. I use long stick out to help a bit. If there was a nice stable flow at first would that help?

The arc is going thru a gas. Does the arc prefer a different more easily ionized gas? I mean a DC or low hz current will take the shortest path unless it finds an easier one...like a little vortex of air amid the argon flow.

Welding is like making babies...everybody likes to do it, some like to talk about it, but you shouldn't do both at once.
Stone knives and bearskins.....and a NEW EVERLAST 164SI !!!
That's my newly shared work welder.
At home I got a Power Tig 185 DV. Nice, but no plasma cutting... Nice tight arc after a second.
Turbo
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I usually tap the pedal to make sure I've got argon already in the cup when I start. If your worried about saving pennies on gas you can probably get a better deal with a bigger tank, but I don't think 25$ for an 80 is that bad. I pay about 25$ to get a 125 filled.

The problem of arc dancing on an aluminum inside corner may be improved with better grounding. I use a meter long piece of stranded copper wire to wrap around my aluminum parts.
Miller Dynasty 210dx

instagram: rsengineeringllc
rahtreelimbs
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I doubt surge wastes as much as the fixed 15 sec. postflow on some of the new machines. At least the surge is fixable.
Last edited by rahtreelimbs on Mon Jun 26, 2017 12:11 pm, edited 1 time in total.
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Poland308 wrote:Switch to a torch that has a built in gas valve. Then you control it even when the machine thinks it knows better. It's a built in needle valve at the torch so you could actually set it and leave it in place with some superglue to get the desired effect.
Do you think something like this would work:

http://www.ebay.com/itm/Vacuum-Pressure ... Swn-tZHAod

Perhaps installed at the machine outlet ?
Image
noddybrian
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If the machine uses standard threaded fitting for a mono cable torch you can just buy a cheap floating ball meter / needle valve & fit it to the machine front then re-fit the torch - I have one on mine & have seen quite a few like it - think Len has it on his though sadly he does'nt seem to be around these days - it is a good check on combined flow when blending from separate cylinders & if you were paying UK price argon any gas saving is good ( insert BOC hate message here ! )
Poland308
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Oscar wrote:
Poland308 wrote:Switch to a torch that has a built in gas valve. Then you control it even when the machine thinks it knows better. It's a built in needle valve at the torch so you could actually set it and leave it in place with some superglue to get the desired effect.
Do you think something like this would work:

http://www.ebay.com/itm/Vacuum-Pressure ... Swn-tZHAod

Perhaps installed at the machine outlet ?
Looks like it's a needle valve designed to regulate flow. I don't see any reason it wouldn't work.
I have more questions than answers

Josh
mpete53
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could this problem be solver by lowering the output pressure on the regulator and opening the needle valve on the flow meter more to maintain the same argon flow?
Poland308
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mpete53 wrote:could this problem be solver by lowering the output pressure on the regulator and opening the needle valve on the flow meter more to maintain the same argon flow?
That would work as well. If you have a regulator you can adjust.
I have more questions than answers

Josh
noddybrian
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Yes - stop buying those retarded flow meter things that are set to insane pressures - get a decent adjustable regulator ( a twin stage oxy gauge works really well - if it bothers you you can swap the little pressure gauges over to some that say argon ) - put a floating ball on the output - adjust it to the minimum pressure needed to achieve fractionally more flow than you use - fine trim the actual flow with the needle valve - no more big surge ! there are dedicated regulators designed to achieve consistent flow without surge but they are kinda pricey for hobby use.
nelson
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Thanks all! I'm gonna fix this for sure. I did a tiny fix job an noticed the surge was messing with the arc. That said, I have 20 feet of 1/4 od tube to the microwelder, and 6 feet of 1/4 I'd to the Everlast....all downstream of the flowmeter. Not good.

In addition I found that even using the pedal, the downslope knob has an effect. Also not good! I have to remember to set it to zero.
Stone knives and bearskins.....and a NEW EVERLAST 164SI !!!
That's my newly shared work welder.
At home I got a Power Tig 185 DV. Nice, but no plasma cutting... Nice tight arc after a second.
taiwanluthiers
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nelson wrote: Fri Jun 23, 2017 11:34 pm HI folks.
I have the welder listed below. It came with a flowmeter. I was wondering if the pressure is too high though.
When I start a weld there's a big gush. I don't know if it's adjustable. I could put a regulator ahead of the flowmeter I guess. I don't know if this affects my Al but my steel looks fine.
I use the same tank for a microwelder. Big gush thru a little nozzle.
I got the same problem. Huge rush of gas when you press the trigger. You're wasting gas, but not only that the rush of gas actually blows the damn arc around, causing the tungsten to burn and getting crap welds.

I found a sticker covering the head of the regulator, and found a set screw. Turning that set screw counterclockwise lowered the pressure. I'm not sure how much (there is no gauge telling you this) but my welder's manufacturer (Andeli) recommends setting the pressure to about 2 bars or so, or 30 psi. This would save gas, and then to set the flow rate (if using a cup) to about 3 liters per minute. You'd use barely any gas if you do this.
Jack Ryan
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taiwanluthiers wrote: Wed Dec 13, 2023 11:43 am
nelson wrote: Fri Jun 23, 2017 11:34 pm HI folks.
I have the welder listed below. It came with a flowmeter. I was wondering if the pressure is too high though.
When I start a weld there's a big gush. I don't know if it's adjustable. I could put a regulator ahead of the flowmeter I guess. I don't know if this affects my Al but my steel looks fine.
I use the same tank for a microwelder. Big gush thru a little nozzle.
I got the same problem. Huge rush of gas when you press the trigger. You're wasting gas, but not only that the rush of gas actually blows the damn arc around, causing the tungsten to burn and getting crap welds.

I found a sticker covering the head of the regulator, and found a set screw. Turning that set screw counterclockwise lowered the pressure. I'm not sure how much (there is no gauge telling you this) but my welder's manufacturer (Andeli) recommends setting the pressure to about 2 bars or so, or 30 psi. This would save gas, and then to set the flow rate (if using a cup) to about 3 liters per minute. You'd use barely any gas if you do this.
You can do that, but the flow meter would no longer be calibrated. In the and, that is not critical as you generally use "enough shielding", not a particular flow. It makes a difference to those following a procedure or wanting to share settings.

Jack
cj737
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This entire years old thread is a solution in search of a problem. :roll: A single, moment of a rush of argon is completely inconsequential to welding. Anyone who doesn’t tap a pedal when first setting up, or checking for leaks after a tank swap is an alien. You can’t even begin to calculate the “lost cost” of argon for that momentary rush of gas.
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