Gas-less MIG

Flux core (gasless) MIG welds are somewhat comparable to conventional arc welds, without the issues of rod starts on longer runs. The actual characteristics vary depending on wire composition, machine settings and operator skill (also weather, which is often the reason for using it on small machines!), but I find they tend to have deeper penetration than an equivalent C-25 weld. Of course, you also have the slag to clean (somewhat) after if building up or desired. There is a huge variety of wire types available.

I'm not familiar with it's use in stainless or aluminum. Aluminum MIG of any production level usually calls for either spool guns or push/pull guns, and the softer wire could cause issues (I have used flux core aluminum gas welding rod before though, and it works fine-just not too pretty). Check with a local weld supplier for the best info- do you still have BOC down under?

Welds are about the same. Biggest benefit I find of the flux core wire is it broad use. Gas shielded wire can be difficult to use outdoors. The slightest breeze can disturb the shielding gas. With the flux core you do not have the problem. Don't weld much so the flux core is all I use.

They make flux core for stainless.

For aluminum they have tried with out much success. Might find some out there. But I caution it's use.

I use FCAW most of the time with mild steel. With practice the welds can be pretty enough for most work.

And cleanliness isn't an issue.

Never tried it with SS and would not with Al.

A flux core welding rig is very handy, portable. Don't have to hump a shield gas bottle AND the welder up five flights of stairs. This is a good choice for field work.

A more conventional shielded arc wire-feed welder is a much better choice (IMHO) is you are more or less stationary... like a fab shop setting.

This is my experience with my work and hobbies. Every craft and trade has it's own needs for tooling.

I've had my present Lincoln 100 AMP rig for at least 10 years. I've never cracked the valve on the tank. Not even sure what's in it. Ar, I think. Somewhere, I've got some solid core wire, I think.

Don't need it for welding brackets onto metal fence posts.

I always ordered a mix of CO₂ and Ar for the steel door shop.

I told the shop guys that if they wanted CO₂, the bottle was to be inverted. Straight Ar was delivered if the regulator was at the top.

^{Yeah, I know... I'm a door guy, gotta get my fun whenever I can.}

Since Tony is down there should he have Ar inverted and CO2 upright?

The ridiculousnessosity of that question is staggering, mind numbing, demonstrating a grasp of obscurity so firm as to be able to choke reason out of any marginally rational resistance to some harebrained scheme presented concept.

You, my friend, may have a bright future waiting for you with LynDoor Industries.

Have your people call my people, they can visit for a while.

There's our next VP of North American product R&D.

We can give him that corner office on the 10th floor.

I moved Brenda into her own penthouse on the roof.

The title of President of Vice. The entire 10th floor for my office and personal spa. No catnip. No need to play with that stupid ball of string during each break. This is an offer I think I can handle.

Send the LynDor corporate jet over to pick me up. Here, I'll give you directions. Fly into the rising sun for about 3 hours. Have the pilot start the descent when over the Museum of Famous Ducks and Mice (they also have a Goofey looking dog but no cats). Look down when in sight of a big pond with a cat on the other side. I'll wave so you know which one is me.

Lyndoor has (2) corporate jets.

Take your pick.

You can use anti spatter, that helps, but gas gives a cleaner weld

Thank you Doorman and all who replied, especially phoenix911 for the laugh.

The company selling the cored wire, advertised it as MIG and obviously everyone knew what I was referring to, I was not aware of the correct term (FCAW), but was sure it wasn't MIG. This company also had vernier calipers for sale with a spare battery.

Most of my welding is done indoors so shield loss is not a problem, my concern was to save money on bottle rental. I often weld into slots and holes and having read all the replies, I may continue with gas.

Tony

I agree with your thought. If you only occasionally do some welding, bottle rental can be a burden that seems unjustifiable.

Vernier caliper replacement batteries? LynDoor Industries has the global lock on these! I believe our newest corporate bulldog BruceFlorida will be contacting these nefarious nogoodnik characters.

In my back yard I stopped using flux core and went to gas because there is less splatter, less clean up and the welds look a little better. Less smoke also makes it easier for a "weld once every other month" amateur like myself to see the weld and control the gun.

If you have to haul it around then flux core is much lighter and easier.

Others have commented on one vs. other for penetration, wind, etc. They know far more than me.

I just got some SS wire and a few bars of SS to try (this weekend maybe). Based upon Mr. Google I expect heat to flow faster putting me at risk of warping issues. I may also need to up the voltage a little. The SS has more resistance and because of the heat flow I may need to try to run faster. Based upon my low skill level and lack of experience I am not expecting to notice a big difference between amateur welding CS and amateur welding SS. I'll let you know after I give it a try.

At work our shop always uses MIG for CS but TIG for SS & AL. TIG burns more time than MIG but looks very nice.

I don't know if you have equipment or are shopping. Based upon advise of others I used the "excess is best" method of selecting a welder. I got the Miller Matic 250 amp MIG unit. It is way overkill (I think it is rated for 1" plate) but that allows me to totally ignore the "x minutes on, y minutes off" duty cycle issues. It's always too hot in Florida and I didn't want to stand around in the sun waiting on the clock. Also, I simply don't have to worry about over stressing the unit. On 1/8" and 3/16" CS I could probably position, clamp and weld 24/7 without any worries.

Expect higher warpage, and ugly backsides to the welds unless you backgas it (fillets aren't a problem). BTW- nice welder!!

I assume you are referring to self shielded Flux cored versus gas shielded MIG.

As has been stated, Flux cored is more versatile and works better in windy conditions, it tends to do a more porous weld, but is more forgiving of less clean base metals, it does leave a lot more spatter which can largely be reduced with an anti spatter spray. You do get slag which, if welding correctly, will generally fall off very easily as it does with MMA welding.

Remember to reverse the connections if going from one to the other (electrode -ve for flux cored, +ve for gas), you may also have to alter the pinch roller pressure to prevent flattening of the flux cored wire, some machines have a double edged roller, either knurled for flux cored or smooth for solid wire.

I use a TIG for SS and Al these days but have used a MIG for SS and Al (but with gas). Many large companies that do a lot of Al welding (Boat builders etc) use Pulse MIG machines.

Al wire generally needs to be a bit thicker to aid feeding, and again the pinch rollers will need attention as also may the inner liner of the gun lead. The nozzle needs to be larger also as Al expands far more than either mild steel or SS

Too bad your weld supply supplier does not have a partial roll of Flux Core to try. Both wire can be run through the same machine with control adjustment. Flux Core is not as easy to weld in overhead or vertical welds, in fact I believe it is not recommended although many good welders can do it. Try both and take your pick.