Welding Tips and Tricks

Just got these delivered. I plan on setting them up today as long as I can find enough of the 1/8" NPT→3/16" barb fittings. I paid ≈$240 for these shipped. Each one is about $56. For a hobbyist, heck of a lot cheaper to mix gases without a $1000+ gas mixer(s).

http://www.dakotainstruments.com

So what will your procedure be? Will you use one of these for comparison?

I suppose I could, but it seems kind of redundant as the flowmeters I ordered would serve kind-of the same purpose (the Argon and CO2 meters), which is what the flowtester you linked is calibrated for. They're just doing it upstream of the machine. I know that seems unrealistic (to measure the flow upstream of the machine), but really they're more for fine-tuning mixtures. I want to try out different Ar-CO₂-O₂ mixtures for spray and pulsed spray.

Oscar, thanks for sharing all of your information. I am only wondering if some type of one way valve is necessary for each of the meters to prevent back flow from one with a higher input.

Even if it did get past the Y, I dont think it can get past the regulator and into the tank (merely a conjecture, not based on any testing/evidence). But none the less, I have ordered some basic check valves for 3/16" hoses on EBay to incorporate into this setup.

Oscar how to propose to deal with different pressures in the gasses to be mixed and how will you proportion the mix?

Pressure is a definite concern you need matching pressure to get reliable results.

Louie1961 wrote:Oscar how to propose to deal with different pressures in the gasses to be mixed and how will you proportion the mix?

Louie,

I'm only going to use standard check-valves. For a hobbyist-tinkering setup, I don't have to worry too much about dealing with the different pressures, as the flowmeters will indicate if there is enough pressure to introduce the dialed flow into the mix (and they do).

For the proportions, I created a thread called "Flow conversion calculator & Gas Mix Calculator". It does all the math for me after I wrote in the equations for the spreadsheet to solve.

Poland308 wrote:Pressure is a definite concern you need matching pressure to get reliable results.

Poland,

I am looking at things from an empirical standpoint. If the flow is registering on the flowmeter, then there is sufficient pressure to introduce it into the Y's for the final mixture. If that previous statement wasn't true, the float in one or more would not move as it would be overpowered by the tank with the standard-flowmeter with the highest pressure.

Case in point, after setting each one as they are all flowing at the same time, I am getting reliable, consistent flow results from each flowmeter each time I squeeze the trigger. For me, that is consistent enough.

Here is the little setup I made for it so it threads onto one of my tanks.






and here it is working, with great consistent results

AMY0qnM3jdg


Empirical evidence doesn't lie.

Oscar,
I have a few questions....
The gauges are calibrated at 50psig according to the instructions. The higher the pressure, the more dense the gas is. At the torch nozzle, the gas is at atmospheric pressure, and has expanded to about 4 times the volume it had at 50psig. Is the adjustment valve at the inlet, or outlet of the gauge? It appears to be at inlet. During flow, what is the pressure at the outlet of the gauge?
The inlet?
If the adjustment valve is at gauge inlet, isn't the gas flowing past the ball at much lower pressure? (Pressure drop occurring at valve).
Seems like that would affect accuracy.

VA-Sawyer wrote:Oscar,
I have a few questions....
The gauges are calibrated at 50psig according to the instructions. The higher the pressure, the more dense the gas is. At the torch nozzle, the gas is at atmospheric pressure, and has expanded to about 4 times the volume it had at 50psig. Is the adjustment valve at the inlet, or outlet of the gauge? It appears to be at inlet. During flow, what is the pressure at the outlet of the gauge?
The inlet?

Very good questions! You're more than welcome to come over to my garage to find the answers. The valve is at the inlet (bottom) of the flowmeters.

VA-Sawyer wrote:If the adjustment valve is at gauge inlet, isn't the gas flowing past the ball at much lower pressure? (Pressure drop occurring at valve).
Seems like that would affect accuracy.

How would that be different from a regular flowmeter attached to a tank and feeding the welding machine directly? The scenario would be same as you describe.

Proof by contradiction: Let's say that statement is true (about accuracy being affected by pressure drop at the valve). If accuracy is indeed affected from the pressure drop occuring at the valve, therefore every flowmeter in existence is inaccurate (because that's exactly what happens; gas flows past the valve). But that is false, so the original premise is not true. Thus, I do not think accuracy is affected.

I don't believe that the check valve will restrict the forward flow of the gas. They are designed to whoa the reverse flow and as far as the flow meters...they will show flow until the gas is prevented to exit the hose. Besides I would like to see Oscar's red room.
IF ya don't try it,,,ya won't know the outcome.

On my current 'regulator/flowmeter', the adjustment valve is on the outlet side. The pressure of the gas flowing past the ball, is at regulated pressure. The pressure drop occurs at the outlet adjustment valve, after the flow has been measured.

VA-Sawyer wrote:On my current 'regulator/flowmeter', the adjustment valve is on the outlet side. The pressure of the gas flowing past the ball, is at regulated pressure. The pressure drop occurs at the outlet adjustment valve, after the flow has been measured.

I can more clearly see what you mean now; your concern is regarding the location of the adjustment valve in relation to inlet/outlet. My HTP flowmeters are the same was as yours - the adjustment valve is after the vertical flowmeter tube. Let's say that there is pressure drop after the flowmeter attached to the tank. Tell me how much pressure drop you are getting on your flowmeter post-adjustment valve then. Once we see how much drop there is, then perhaps we can discuss this with empirical data. I have my flowmeters wide open at the tanks, so technically there shouldn't be any, or perhaps negligible pressure loss going into the Dakota flowmeters.

Oscar, can you post a pic of the setup / connection of the Dakota meters?

Nothing fancy on the backside, just 1/8" NPT to 3/16" barbs for the gas hose that I'm using. Gas inputs on the bottom of the meter, outlets up on top. Then I tied the Ar, CO₂, and O₂ outlets into two Western 111 Y's like so: (please excuse the messy welds, I had painted it white only to realize I had it upside down after the fact, lol, so I just cut it apart and re-welded without cleaning much of the paint off )




The Helium is not connected since I'm not using it any time soon. But it's there just-in-case.




With this configuration, I can shut off any of the three gases, and do any binary Argon-based mix (C25 I don''t do since I have C25 tanks already; in this setup I'd be limited to 20CFH total flow since I can only dial in 5 CFH of CO₂ on that meter).


I just checked the flow at the Dakota's with and without the inner flow-tubes & floats inside the flowmeters attached to the tanks, and there was no discernable difference of flowrate at the Dakota's with the tank flowmeter valve wide-open. So basically what I'm saying is that once you have the tank flowmeter valve wide-open, it's like the valve isn't even there, and the pressure in the flowmeter (post regulator) is essentially the same before and after the valve, hence little to negligible pressure loss.

I did manage to find this bit of info. Notice under the correction factor chart, the note about adjustment valve location and pressure.

VA-Sawyer wrote:I did manage to find this bit of info. Notice under the correction factor chart, the note about adjustment valve location and pressure.

I don't know where/what you're looking

My mistake. I was trying to attach a file (PDF) which isn't allowed. I thought that I had deleted that post. I will figure out how to get the info posted later.

In any event, I am 100% confident it is working as expected.

Update.

I'm on my 4th Frankenmixer that I've been commissioned to build. Mine is working as good as its ever been. The 2nd was just Ar/CO2. The 3rd (that I'm building right now) is Ar/CO2/CO2/O2. The 4th will be Ar/He

Finished the 3rd Frankenmixer. Headed out to South Carolina tomorrow.



Now to start on the 4th one.

Looks great Oscar!

This reminds me, Jody has said in numerous videos that "just a little bit of helium" adds a lot of heat to a weld and will make up for a under powered machine, though it's usually in aluminum videos, Since you have this setup, I would be really curious to see the actual difference certain percentages of helium makes at a set amperage.

sbaker56 wrote:This reminds me, Jody has said in numerous videos that "just a little bit of helium" adds a lot of heat to a weld and will make up for a under powered machine, though it's usually in aluminum videos, Since you have this setup, I would be really curious to see the actual difference certain percentages of helium makes at a set amperage.

I'm sure you are. Unfortunately Helium is worth 100x it's weight in gold, so I won't be using it up anytime soon unless I absolutely have to for a project that my Invertig 400 won't be able to handle. You can always sponsor me for the cost of shielding gas and we can take it from there. A 125 ft³ of Helium is $180 per refill, locally here. You game?

Oscar wrote:

sbaker56 wrote:This reminds me, Jody has said in numerous videos that "just a little bit of helium" adds a lot of heat to a weld and will make up for a under powered machine, though it's usually in aluminum videos, Since you have this setup, I would be really curious to see the actual difference certain percentages of helium makes at a set amperage.

I'm sure you are. Unfortunately Helium is worth 100x it's weight in gold, so I won't be using it up anytime soon unless I absolutely have to for a project that my Invertig 400 won't be able to handle. You can always sponsor me for the cost of shielding gas and we can take it from there. A 125 ft³ of Helium is $180 per refill, locally here. You game?

, I need to see what it costs here, I knew helium was expensive but I would've expected that would be the fill cost on a 330CF not a 125, what do you pay for argon?