Questions about MIG welding with gas, and the consumeable parts

[amanda11270]

I am an amateur at welding. I read a lot, watched a lot of videos, but still have a few questions. Im pretty good at fabricating, built my own tractor cab and numerous other things with my MIG. However I still have a few questions. I have only ever used flux core wire with no gas. If I attach shielding gas to my MIG, will it eliminate the spatter I get now with the flux core wire? I can usually clean up my welds good with my grinder, but will the gas make them have less or no spatter? Also, when do you have to replace the piece in the center of the MIG gun where the wire comes thru, its the copper piece sized for .035 wire? And lastly, this past time I used my MIG for a project, I got a lot of spatter sticking to the outer shield of the gun, I never had that happen before, it was so bad I had to stop and clean it as it almost blocked it closed.

Almost forgot, if I do get a shielding gas bottle, what type of gauge do I use, is it the same type used for purging nitrogen when brazing refrigeration lines?

My welder is a 220V MIG, with four power settings, and adjustable wire feed speed, Chicago Electric from Harbor Freight. It seems to work pretty well for something from Harbor Freight Tools, but I'd like to know what I need to make a better looking weld without having to clean it up as much.

 

[mrmikey]

If I attach shielding gas to my MIG,....

Make sure your machine will accept a gas setup

.....will it eliminate the spatter I get now with the flux core wire?

It will eliminate some of it. There's a lot of variables that produce spatter, cleanliness of the material, fit up, type of joint etc.

Also, when do you have to replace the piece in the center of the MIG gun where the wire comes thru, its the copper piece sized for .035 wire?

Called a contact tube, it screws into the diffuser that the gas comes out of and that has the threads or sleeve for the nozzle to fit on. As for replacement, could be 5 minutes, 5 hours, 5 days again, there's a lot of variables to contend with. How long an arc, how far back in the nozzle is the end of the tube. If I'm welding on clean material I can sometimes get a roll of wire from one tube. You'll know when to replace it, the wire will start to feed uneven and sometimes you can actually feel it grabbing, you can clean them up with a file and a set of tip cleaners if not too bad.

I got a lot of spatter sticking to the outer shield of the gun, I never had that happen before, it was so bad I had to stop and clean it as it almost blocked it closed

.
Normal depending on your situation. Get a can of spatter spray or tip dip, it'll make the spatter easy to remove.

if I do get a shielding gas bottle, what type of gauge do I use...

Flowmeter, you're measuring flow as opposed to pressure like what would be on an acetylene/ox setup. Not sure what's used for refrigeration.

My welder is a 220V MIG, with four power settings, and adjustable wire feed speed, Chicago Electric from Harbor Freight

Not sure of the specs of the machine but I think it's going to be limited. Don't forget to change your polarity when going to solid from fluxcore.....Mike

 

[Shield Arc]

Are you running self shielded flux core with a regular Mig gun? If so you'd be better off to remove the nozzle, and protect the diffuser some how.
Here is what a dedicated shelf shielded flux core gun looks like.

 

[Stimw]

With my Miller MIG I rarely replace the tip. Sometimes it will burn back and most of the time I can get the wire loose and keep using it.
You need to size the tip to the wire size you are using.
I only use .035 wire. I tried using .023 and could not get enough heat on thicker metal. For thin metal I back off and can still weld 18 ga.
For shielding gas FOR STEEL you can use CO2 ( course weld, a lot of spatter) , 75/25 (argon/CO2) works good not too much spatter. My local supply has Stargon which I can't tell the difference between it and 75/25. ??
I find that a Flow Gauge uses more gas than a regulator.
With a regulator I back off on pressure until I see the weld getting porous (holes) then move pressure up just a little to correct. Doing it this way I use way less gas. I haven't changed my setting in years!!
You can use WD-40 on surrounding areas to keep spatter from sticking.

 

[kenmac]

I could not imagine trying to use a regulator to regulate my gas flow on my mig. Most people I know use this HTP Argon CO2 MIG TIG Flow Meter Regulator Welding Weld | eBay
Hey, Do What ever works for ya

 

[Arc weld]

You should have a lot less spatter running solid wire. C-25 is the most common shielding gas. Spatter spray would be better to use than WD-40, that's what it's made for.

A flow gauge will measure CFH the same as flow meter. Regulators measure pressure and aren't used for MIG welding. A flow gauge looks the same as a regulator but the output gauge reads CFH not PSI. A flow meter has a vertical tube to measure CFH. Flow meters and flow gauges generally have the pressure pre-set around 30 PSI.

You usually know when to change the contact tip. It's either had the wire burn back, got a big blob of spatter on it, the wire feeds erratic or it's ovaled out. Contact tips are pretty cheap, so there's no excuse for not having a few spares. Good to have some spare nozzles and a diffusers as well.

 

[kenmac]

What are you calling C-25. All I have ever used in 30 yrs is 75/25. Is C-25 something new less expensive ?

 

[Shield Arc]

C-25 is 75% argon, and 25% CO2.
I change contact tips like Arc weld says when they get ovaled out.

 

[Stimw]

I have the Flow Meter, the one with the standing tube with the ball in it and the little adjusting knob on the side. It's in my welding supply/accessories draw.
When I used it I went through way more gas and for me it's at least a 2 hour round trip for a refill.
Everywhere I have ever worked used regulators on the MIG's and my Miller MM210 came with the regulator.
They did use Flow Meters on the TIG machines.
The bottle in the pic shows the type of gas.

 

[mrmikey]

Everywhere I have ever worked used regulators on the MIG's and my Miller MM210 came with the regulator.

You sure it's not just a gauge flowmeter rather than a ball type. Most of the flowmeters at work are the gauge type because the vertical plastic type were always getting broken.....Mike