Question About Welding

[f-x-d-w-g]

I recently bought a Hobart 140 MIG welder.  It came with flux core wire, regulator and gas hose, but no bottle.  Can I use the flux core wire with C25 gas until it's used up or do I need to trash it and get solid wire if I'm going to use gas?

[Ultrashovel]

I recently bought a Hobart 140 MIG welder.  It came with flux core wire, regulator and gas hose, but no bottle.  Can I use the flux core wire with C25 gas until it's used up or do I need to trash it and get solid wire if I'm going to use gas?

The Hobart is a nice welder. You would be wasting money on shielding gas to use C25 along with your fluxcore, however. Fluxcore is used without shielding gas. That's what it's for. There is such a thing as dual shielded welding but that requires special wire.

If you don't like the fluxcore, simply remove it and place the roll in a plastic bag so it won't corrode. It will be there as a backup later on.

A good choice for welding wire on a smaller MIG would be .023 wire. I have good luck with Lincoln solid .023. (they actually call it .024 in Lincoln because it's nominally 0.6 mm). You can get that at Lowe's or Home Dept for about $8.95 per roll. They also have the tips for the smaller wire if you don't have them. It may be necessary to change to a different roller for the smaller wire. Hopefully your machine came with a spare roller for solid wire.

It's also necessary to change polarity for solid wire if you have been using fluxcore. Fluxcore uses so-called Negative Polarity, that is, the wire is electrode negative. For solid wire, it's necessary to change over to positive polarity where the wire is electrode positive. There are instructions in your manual and probably also inside the hood of the machine.

As to the type of gas you will use for shielding - C25 makes a nice looking weld. The only negative thing about it is that it's fairly expensive compared to straight C02. I use straight C02 in my Lincoln SP 175 Plus (220VAC Machine) because it gives greater penetration and works well for the things I do.

While straight C02 is less expensive (about half the $ cost of C25), it does cause more splatter on the area surrounding the weld. You can counteract this by usng an anti-splatter spray and keeping the tip clean and wet with welding gel. (Available at a welding store)

Forgive me if you already know this: The other difference between C25 and straight C02 is the way they sell it. C25 is sold by the cubic foot as a gas and C02 is sold by the pound as a liquid. One pound of C02 equals approximately 8 cubic feet of gas. So, if you set your flowmeter to give you about 20 SCFH (standard cubic feet per hour) a 20 pound C02 bottle will last you arond 8 hours of welding (20# X 8 = 160 cu ft. equivalent) Another reason I like C02 is because it has a smaller bottle relative to the gas it will produce.

If you have a small C25 cylinder, say 40 cu ft, it will only last you around 2 hours and it's a genuine PITA visiting the welding store more often than necessary. They also hit you with a HAZMAT fee nowadays ( I call it the Al Gore Private Jet fee).


Happy fabricating~!

[f-x-d-w-g]

Great info, Ultra!

I took a one-week class which touched on everything (I think):  Gas, stick, MIG, TIG, and plasma cutters.  It was fun and I learned enough to know what a weld should look like and how to setup and clean up.  So far, I've only done small repairs and had pretty good results.  I reattached the collar on the front tube of my Propipe to stop an exhaust leak, modified a christmas tree holder to accept a wider variety of tree sizes, and a small mod to the exhaust chute of my snow blower.

I was just asking about using gas right now because there's no flux to clean up after welding.  Maybe when (if) I start chopping my Shovel, I'll switch to solit wire and gas.

Again, thanks for taking the time for such a thorough response.

[Dakota]

  I learned something too, I didn't know the polarity needed to be reversed to switch between flux core and solid wire.  No wonder I didn't like using flux core-I didn't reverse the polarity.
Thanks

[Memnar]

I recently bought a Hobart 140 MIG welder.  It came with flux core wire, regulator and gas hose, but no bottle.  Can I use the flux core wire with C25 gas until it's used up or do I need to trash it and get solid wire if I'm going to use gas?

The Hobart is a nice welder. You would be wasting money on shielding gas to use C25 along with your fluxcore, however. Fluxcore is used without shielding gas. That's what it's for. There is such a thing as dual shielded welding but that requires special wire.

If you don't like the fluxcore, simply remove it and place the roll in a plastic bag so it won't corrode. It will be there as a backup later on.

A good choice for welding wire on a smaller MIG would be .023 wire. I have good luck with Lincoln solid .023. (they actually call it .024 in Lincoln because it's nominally 0.6 mm). You can get that at Lowe's or Home Dept for about $8.95 per roll. They also have the tips for the smaller wire if you don't have them. It may be necessary to change to a different roller for the smaller wire. Hopefully your machine came with a spare roller for solid wire.

It's also necessary to change polarity for solid wire if you have been using fluxcore. Fluxcore uses so-called Negative Polarity, that is, the wire is electrode negative. For solid wire, it's necessary to change over to positive polarity where the wire is electrode positive. There are instructions in your manual and probably also inside the hood of the machine.

As to the type of gas you will use for shielding - C25 makes a nice looking weld. The only negative thing about it is that it's fairly expensive compared to straight C02. I use straight C02 in my Lincoln SP 175 Plus (220VAC Machine) because it gives greater penetration and works well for the things I do.

While straight C02 is less expensive (about half the $ cost of C25), it does cause more splatter on the area surrounding the weld. You can counteract this by usng an anti-splatter spray and keeping the tip clean and wet with welding gel. (Available at a welding store)

Forgive me if you already know this: The other difference between C25 and straight C02 is the way they sell it. C25 is sold by the cubic foot as a gas and C02 is sold by the pound as a liquid. One pound of C02 equals approximately 8 cubic feet of gas. So, if you set your flowmeter to give you about 20 SCFH (standard cubic feet per hour) a 20 pound C02 bottle will last you arond 8 hours of welding (20# X 8 = 160 cu ft. equivalent) Another reason I like C02 is because it has a smaller bottle relative to the gas it will produce.

If you have a small C25 cylinder, say 40 cu ft, it will only last you around 2 hours and it's a genuine PITA visiting the welding store more often than necessary. They also hit you with a HAZMAT fee nowadays ( I call it the Al Gore Private Jet fee).


Happy fabricating~!

Really good advice!

[Ultrashovel]

  I learned something too, I didn't know the polarity needed to be reversed to switch between flux core and solid wire.  No wonder I didn't like using flux core-I didn't reverse the polarity.
Thanks

Yeah, that's the case and I really don't know why. I've never heard a satisfactory explanation for the polarity requirement for solid wire welding. (GMAW). All I know is that it works. You mght think it would be the opposite since most of your welding on a TIG welder is done using DC- polarity. Flux core (FCAW) apparently needs to have DC minus.

Flux core is great if yo ever weld outdoors, like building a fence out of pipe. I heloped my neighbor and we used fluxcore because the wind can't bother the shielding gas since there isn't any.

If you really like to fabricate and make little items out of metal for your bike, a MIG welder is a good place to start. You can't go wrong with Hobart, Lincoln or Miller. They all work and do a good job. With straight Argon and a proper cable liner you can even weld stainless steel and aluminum with a MIG.

If you like to take classes, most of the local community colleges have a welding class. I've been welding with stick and oxygen-acetylene for years but I never did TIG until I bought a used machine in 1994. I took a two semester class at a local CC and it was great. Both semesters cost me less than $100 and I bet I used a lot more gas and welding materials than that.

Happy Trails!