TheSamba.com :: View topic - Shielding gas settings for MIG welder

Mon Sep 30, 2019 2:10 pm

I am using an Eastwood MIG 135 with .023 wire I purchased at my local Airgas store. I also have a 40 Lbs. gas bottle with c25 (I believe.)

I ran out of gas about half way through a 2 Lbs. sppol. I dont remember what I had the flow rate at and without gas I can't tell at the moment. My amateur tack/stitch welds on sheet metal look good to me but I don't understand all I know about that.

These questions are aimed primarily at sheet metal patch welding
- What is the recommended flow rate for .023 wire?
- Is it gas mix specific?
- Does gas mix affect longevity?
- What is an acceptable bottle to spool ratio? (40 Lbs. bottle : 2 Lbs, spool)
- Any tips on how to make the gas last longer? (other than a bigger bottle)

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Emil

Tue Oct 01, 2019 1:56 pm

Your regulator may be set to 30cfh, and the nozzle may output around 20cfh normally.

MIG gas should last a while, but it depends on how big of a tank you have.

Be sure you are reading the gauges properly. I made a mistake once of confusing the L/min with the cfh on the gauge and kept blasting my way through argon on my TIG.

When you aren't using your welder, be sure to turn the bottle knob all the way tight. That way any tiny bit of a leak won't leave you without gas.

Tue Oct 01, 2019 2:23 pm

Set you glow at 15-18 while flowing. If you just set it at 15 he pressure will drop when you pull the trigger. .

Tue Oct 01, 2019 2:48 pm

The small bottle will last very little. If your going to weld any amount, get the bigger bottles.

Tue Oct 01, 2019 6:53 pm

I turn the flow down as much as possible to still provide a clean looking weld when welding sheet metal around 8 L/min because I can’t afford to take a day off work to refill the bottle all the time. Ymmv

Wed Oct 02, 2019 7:28 am

You may try some .030 flux core wire. It works great if you are welding dirty stuff and I've used it on thin body repairs in the past as well. This required no gas at all. I think you may need to switch the DC polarity in the welder when using flux core, vs. traditional MIG.

Otherwise the only way to get the MIG working right is to use the right amount of gas flow. Remember, you'll need even more gas flow if you are welding outside, where wind is blowing away your gas.

Thu Oct 03, 2019 8:43 am

Matt Wilson wrote: You may try some .030 flux core wire. It works great if you are welding dirty stuff and I've used it on thin body repairs in the past as well. I switched to my spool of Flux Core but it is .035. Even turning the heat down and allowing a little extra stick-out I was blowing holes in the metal. I need to do some repairs on the rockers (dirty on the back side) so I will get a spool of .030 FC and give it a try.

Thank you all for the suggestions and advice.

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Emil

Thu Oct 03, 2019 10:21 am

I use 0.030 solid wire with 15-20 CFH. I was going through it fast and realized I had post flow set :oops:

Thu Oct 03, 2019 6:48 pm

Emil,

Try .030 wire with the gas. I like it much better than .023. I have a cheap Lincoln MIG and it seems to like the thicker wire. I didn't change any settings with the thicker wire and seem to get nicer welds with less blow through. I also found sometimes moving from perpendicular to more 45 degrees seemed to help as well.

Mark

Sat Oct 05, 2019 2:49 pm

Dibaltic wrote: I use 0.030 solid wire with 15-20 CFH. I was going through it fast and realized I had post flow set :oops: I didn't even know that was a thing. My Eastwood MIG 135 apparently has post flow but I can't find any information in the manual on how to turn it off. So it's either spend a bunch on gas or figure out how to make flux core work with sheet metal. Fortunately you guys have provided some good advise.

Does "Easy Grind" flux core wire exist?

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Emil

Mon Oct 14, 2019 12:21 am

Evil_Fiz wrote: Dibaltic wrote: I use 0.030 solid wire with 15-20 CFH. I was going through it fast and realized I had post flow set :oops: I didn't even know that was a thing. My Eastwood MIG 135 apparently has post flow but I can't find any information in the manual on how to turn it off. So it's either spend a bunch on gas or figure out how to make flux core work with sheet metal. Fortunately you guys have provided some good advise.

Does "Easy Grind" flux core wire exist?

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Emil

Look for cubitron grinding products. Amazing stuff.

The gas selection typically depends on the wire used. Some wire is for both co2 and 75/25 (aka mix gas) and some are for one or the other. It will say on the box.

Co2 penetrates deeper and does a bit better in the wind plus it’ll deal with dirty metal a touch better. More spatter and a lower deposit rate of metal are some negatives.

75/25 (mixed gas, co2 with argon added) doesn’t penetrate as deep, wont deal with dirty metal quite as well or the wind (Agon isn’t heavy) but spatters less and is easier to produce a pretty weld.

I prefer 75/25 for sheet metal. There’s a lot of mixes (80/20 and even some with oxygen added).

Gas flow depends on the situation. If it’s too low you’ll get porosity (pin holes) and too high you’ll get worm tracks (looks like lines in the top of the weld). Overhead welding takes more gas than flat. Co2 requires a higher flow rate than 75/25 in most cases. I keep it around 15 cfm. A pound of co2 contains about 8.7 cubic feet. You should drop test your hoses for gas. Open the bottle with gauge hooked up and close it after a few secs of being open. Then watch the gauge for any drop. A drop in the high pressure side is a leak at the bottle and if you have a flow meter that’s a gauge (not a ball in a tube) if it drops then you have a leak between regulator and the welder. If you have a flow gauge that’s a ball you watch it with the tank open. The ball should settle to the bottom of the tube. If it doesn’t (they’ll sit ALMOST at the bottom of tube) you have a leak between regulator and welder.

I wouldn’t use bigger than .024. Welding sheet metal is different than plate steel (like buildings and ships). You’ll be doing small stitch welds and triggering/zapping it in more than long stretches.

Flux core can be used for sheet metal but why?6013 (stick) can be used too.. Dispite claims of flux core being “better” for dirty metal experience says that’s incorrect. I was on a job where they ran coreshield 8 and Lincoln 232 inner shield and couldn’t get it to run until all the crap in the base metal was melted out OR I ran 6010 over it first. The wire I’m use to running is dual shield (gas and flux) and is said to not tolerate dirty metal BUT it does way better than that inner shield. Typically if something is fit with a huge gap or super thin (not structural) i’ll Use mig.

Polarity has a bigger affect on penetration than gas used. Electrode negative (ground is positive) penetrates less but not all gas shielded wire can be ran that way.

Mon Oct 14, 2019 4:17 pm

@ekacpuc: :shock: =D>
Amazing coverage on the topic. Thank you for the explanation and details.

I was at Home Depot yesterday and picked up a 1 Lb. spool of Lincoln .030 Flux core. After messing with the settings for a while I was able to bridge a pretty wide gap with some of the ugliest welds ever committed to sheet metal. I still have some .023 MIG wire so I will be refilling my bottle with 75/25. I also need to check with Estwood to find out if there is a way to disable post-flow on my welder.

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Emil

Tue Oct 15, 2019 5:29 am

Evil_Fiz wrote: @ekacpuc: :shock: =D>
Amazing coverage on the topic. Thank you for the explanation and details.

I was at Home Depot yesterday and picked up a 1 Lb. spool of Lincoln .030 Flux core. After messing with the settings for a while I was able to bridge a pretty wide gap with some of the ugliest welds ever committed to sheet metal. I still have some .023 MIG wire so I will be refilling my bottle with 75/25. I also need to check with Estwood to find out if there is a way to disable post-flow on my welder.

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Emil

Gotta make sure your wire will work with mixed gas. You can google pics of how to tell.

Also 75/25 uses a different regulator end. 75/25 is female threads on the bottle where Co2 is male IIRC. They make adapters though.

Inner shield isn’t bad. It was made to deal with the wind and runs totally different than gas shielded. You can increase the stick out to bridge a gap with it but it’ll sometimes give worm tracks. Gas shielded (gmaw or hard wire) you can’t increase the stick out (decreases volts at the arc) too much due to gas BUT it has no slag so you can “trigger” or “bump” it to bridge a gap and have it look nice. Just pull trigger for a sec then let go and wait until it cools then repeat. The more bumps/zaps you give it the hotter it gets and the longer you’ll have to wait to cool down before you can bump/zap/trigger it in again. But there’s no slag to hurt the integrity of the weld.. also you can whip it. Keep the trigger pulled and let the puddle build then whip out of the puddle (staying in weld seam/joint) then whip back in front of the first puddle, hold and repeat. Trigger is pulled the whole time. The farther you whip out and back the more it cools AND the arc will somewhat “clean” the metal in front of the puddle.

Hope it helps.

Tue Oct 15, 2019 5:35 am

Normally the spool of wire says M or C or m/c on it. M being mixed and c being co2

Post flow and preflow adjustment is sometimes inside the box up towards the top corner near the front of the box. I’ve seen it in the back but figured you wouldn’t have missed it.

While I don’t enjoy welding anymore I do enjoy helping others.

Sun Nov 17, 2019 4:53 pm

Evil_Fiz wrote: I am using an Eastwood MIG 135 with .023 wire I purchased at my local Airgas store. I also have a 40 Lbs. gas bottle with c25 (I believe.)

I ran out of gas about half way through a 2 Lbs. sppol. I dont remember what I had the flow rate at and without gas I can't tell at the moment. My amateur tack/stitch welds on sheet metal look good to me but I don't understand all I know about that.

These questions are aimed primarily at sheet metal patch welding
- What is the recommended flow rate for .023 wire?
- Is it gas mix specific?
- Does gas mix affect longevity?
- What is an acceptable bottle to spool ratio? (40 Lbs. bottle : 2 Lbs, spool)
- Any tips on how to make the gas last longer? (other than a bigger bottle)

-----
Emil
I'm not sure which size tank a 40 pounder is, but it sounds like a "D" tank (about 3 foot tall). That tank should last a while. If I'm doing a lot of welding, it'll last a week. If I'm doing some hit and miss welding, it'll last a year. It really depends on how much welding I'm doing, or if my son is doing a bunch of welding.
I don't buy a 2 lb roll of wire, but I keep 1 around for emergencies when I run out of my 11 pound roll. Ideally you want to set the gas flow as low as possible, as it should be like a light breeze across your face. I'll got thru 2 and a half 11lb rolls to one "D" tank of gas. I'm using a 30 year old Snap On mig welder. It still works great, but it doesn't look brand new any more.

You might want to contact Eastwood about the post flow, and find out if it's set to run while the trigger is pulled, or if there's a switch you can turn off.

It's like I told a buddy last night, no 2 welding machines are alike (even if they're supposed to be), and no 2 welding operators are alike. Everyone welds differently, and every machine operates differently. I had come over to help dial in his WeldMark 145 welder for him. It ran pretty decent too. I didn't care for the delay of the wire spitting out, but I guess it's something you get used to if you use it enough.

Mon Nov 18, 2019 8:16 am

Bobnotch wrote: I'm not sure which size tank a 40 pounder is, but it sounds like a "D" tank (about 3 foot tall). Thanks Bobnotch for your reply. It is the kind of relative comparison I was looking for. My gas bottle stands 24" from base to top of valve. I am calling Eastwood today to get info on post flow settings. If I have to live with post flow I will probably upgrade to a larger bottle.

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Emil

Mon Nov 18, 2019 1:18 pm

Well boys and girls it turns out the problem was a DOH! moment; a nut loose between the floor and the trigger :oops:

I spoke to the tech at Eastwood. The conversation went something like this:

Me: Can post flow be disabled on the MIG 135
Tech: No, and then explained the benefits of it and how it is a minimal amount of total gas consumption.
Me: OK
Tech: What do you have the gas set to?
Me: Between 12 and 15.
Tech: On the red or black scale?
Me: Not sure, I can check.
Tech: Make sure it is on the red scale, a lot of people set it on the black scale by mistake.
Me: Thanks.

Sure I had it set between 12 and 15... L/min. (Black scale)
That's about 3 times more gas than 12 - 15 CF/hr. (Red scale)

Although I had read the "manufacturers opinion" cover to cover to find the recommended settings and consulted the YouTubes for corroboration, I failed to pay close attention when reading the gauge. In my defense the black scale is the outer, more prominent scale on the gauge. At least I didn't put Diesel in a Petrol motor.

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Emil