Flux Core Amps vs thickness

JCoastie · May 26, 2022

I have never welded, but tired of bugging the neighbors, so I have pretty much decided on a 115v Flux Core welder just to fix little things that break.

How is it that something like a Century FC90 with 90 amps is advertised up to 1/4 inch and something more powerful like the Yeswelder 135 with 135 amps is only rated to 5/32?

How can less current weld thicker material?

WranglerX · May 26, 2022

Because the spec of the Century FC90 are grossly over rated ... Even the top end 120 Volt machines (which max out about 140 amp) are only good up to about 1/4 inch.. Need to weld something bigger you either pre heat area of the weld or do multi pass or get 240 Volt, 250 amp machine.......

Anything lower than 120 amps is going to be a disappointment.. Anything below 120 amps will not handle 1/4 inch material. My Hobart Handler 140 maxes out at top heat and 1/4 inch material.... Several things to consider The amperage & voltage that create the ARC is what causes the fusion between the metal parts.... Also size of the welding filler wire, whether it be flux core (FCAW) or solid wire and shield gas (GMAW) if you turn up the heat fully and it not enough to get good fusion bond, its just another failure, if you have larger machine you can always turn the heat down if you are running to hot....

Personally I would not buy any welder that is not dual capable, meaning it can run either FCAW or GMAW..... I moved away from flux core to solid wire with shield gas many years ago and never loaded flux core since... But with any wire welding process, preparation is everything...

Suggest you spend some time in the MIG Welding section of the link below...

Welding Tips and Tricks - TIG, MIG, Stick and a pantload of other info

Down and Dirty Welding tips and tricks , No PhD's allowed

weldingtipsandtricks.com

Gentlemen also has some very informative videos on YouTube...

California · May 26, 2022

JCoastie said:
How can less current weld thicker material?

Deceit?

Basically a 110 v welder is a 90 amp welder, if its on a household circuit.

One with semiconductors instead of a big heavy inefficient transformer will be a little more efficient, so a few more output amps.

Step up from a 15 amp household wall plug to the 20 amp circuit you might find in a shop and this can output more before it trips the breaker.

The Century 130 110v welder I had, needed a different special cable to the wall and specified a 30 amp breaker there, before it could output the advertised '130 amps'. It was marketed to auto body shops so a special 30 amp circuit for it might be reasonable in that application, in contrast to home use.

I recently bought an Amico MIG-130A dual-voltage flux welder just for its portability. (18 lbs). It welds great on a 240 volt outlet. The 110 volt capability is just for where I need to carry it to somewhere without a 240v outlet. it probably does 90 amps on 110v, despite the '130 amps' claimed 110v capability. These are only $149 on Amazon. But if you buy anything that cheap be sure to also buy the $30 4 year warranty listed there!

rangerfredbob · May 27, 2022

The modern tiny inverter welders can actually weld pretty good... I've been using and abusing the Harbor Freight Titanium MIG 170 for a few years on flux core with all sorts of inputs (4kw generator on 120V, long extension cords, 220V, etc...) and using the chart on the side cover as a starting point it welds pretty good... much more forgiving than the old Chicago Electric 100A transformer deal, which works fine if you ignore most normal welding advise... The little guy they have now on sale for $170 now and then welds decent too.

Single pass on big stuff isn't gonna work if you want it to be strong, but multi pass should be fine, I've welded with good penetration on 1/8" a lot

5030 · May 27, 2022

All good comments.

p0diabl0 · Jun 8, 2022

I had the cheapo HF Chicago Electric flux core for a while. I have a 30 amp RV hookup in my yard and you could tell - it used it when needed. Plugging it into a house outlet wasn't nearly the same.

metalbender · Jun 8, 2022

I've had the HF toaster size inverter stick welder for quite a while. With proper technique and selection of rods, it's amazingly capable.

amhicks21 · Jun 8, 2022

I avoid flux core welding whenever possible because of how dirty it is and how the welds don't look as nice but it does have some advantages. The flux insulates the weld a bit and since there is no shielding gas continually blowing on the weld you can weld a bit thicker steel with the same amperage. Its also nice if you need to weld on something outside since a breeze will blow mig gas away and ruin welds. The wire price sucks though. The same size spool costs twice as much as mig and you go through it like twice as fast because of the flux content. Anyway... I guess what im getting at is you should really consider getting one what can be used both as a flux core and mig machine. I bought a lotos mig140 about 4 years ago just to do small stuff at home and i mainly use flux in that because I work under a carport a lot and thats been surprisingly nice for 400 bucks. It seems to be built nearly as well as the lincoln welder i use at work. Like California said you absolutely cant run over a 90 amp welder on a 15 amp breaker. I had to have a 25 amp put in to run a 140 amp because it would blow 20's every few minutes.

WranglerX · Jun 8, 2022

Ditto on big CB for 140 amp machine... My HH 140 can pop a 20 amp breaker on top heat... Ended up putting in 30 amp dedicated welder circuit...

jaxs · Jun 9, 2022

JCoastie said:
I have never welded, but tired of bugging the neighbors, so I have pretty much decided on a 115v Flux Core welder just to fix little things that break.

How is it that something like a Century FC90 with 90 amps is advertised up to 1/4 inch and something more powerful like the Yeswelder 135 with 135 amps is only rated to 5/32?

How can less current weld thicker material?

Can you say marketing hype? Actually you can weld up to 3/4" with a 115 volt welder. Thats "up to" but not including 3/4" A-N-D if you go from 1/8" SKIPPING 3/16,1/4",5/16",3/8" and 1/2"

It could also be said you can weld on skyscraper buildings with 120v welders but the building might collapse for lack of penetration.

Redneck method of testing whether you have enough welder is if you can't intentionally burn through material,the welder is too light in the pants.

California · Jun 9, 2022

jaxs said:
Redneck method of testing whether you have enough welder is if you can't intentionally burn through material, the welder is too light in the pants.

Thanks for slicing through a lot of obscure theory and posting this practical test for appraising a small welder!!!

ray66v · Jun 9, 2022

I agree that you should try to buy a 220v welder.

You will probably use it more than you think, and be glad you did.

As far as welding 1/4" with a 110v welder, yeah, it can be done. If you bevel the edge, or heat the metal first, you can do it on a limited basis. But, it's more like work.

The other problem you'll have welding heavy material, is the duty cycle. It's only going to run on full power for a limited amount of time. Seems like as soon as you get enough heat in the metal to start to make a nice weld, the automatic shut down to keep from overheating kicks in. That's the other reason you want the bigger machine.

Flux core wire splattering is a bit too much for me. So, I like using the shielding gas. But, flux wire does have an advantage if you're welding outside.

jaxs · Jun 27, 2022

Since you say you've never welded before I advise you read a thread just above this one(What's happened to Shield Arc). Reading that thread should convince you Shield Arc was the undisputed guru of welding. Once you trust every word the man wrote,search Author "Shield Arc" to read advice he gave us. In addition to insight on welding in general,you will notice how important he says penetration is. After all the hoopla and dust settles from this thread,the answers to your question of 120v vs 240v welders come's down to penetration.

GeneV · Jun 28, 2022

JCoastie said:
I have never welded, but tired of bugging the neighbors, so I have pretty much decided on a 115v Flux Core welder just to fix little things that break.

How is it that something like a Century FC90 with 90 amps is advertised up to 1/4 inch and something more powerful like the Yeswelder 135 with 135 amps is only rated to 5/32?

How can less current weld thicker material?

I had that welder, started on it, and then went to stick. You could do 1/4" on it, basically crank up the feed and amps to max and go for it. At the least, you'll get there with multiple passes.

Disclosure to running this machine at max amp: make sure you're wearing comfy shoes, coz you'll be taking frequent trips to the electrical panel to flip the popped breaker...especially if it's a 15 amp breaker.

jaxs · Jun 28, 2022

Gluing metal together with molten wire fall's way short of permanently joining it. You can melt filler on 1/2" metal with a 120 volt machine but that doesn't qualify as "welding it",regardless what buds on the web claim. Very few homeowner/diy projects exceed 1/4" so if 120 volt wire welder was suffecient,there would be little to no market for Hobart Handler 190 and similar machines that are so popular. It's difficult at best for newbies without people encouraging them to start off with machines that severely limit their ability.

alexpops · Jun 28, 2022

Go with 110/220 multi voltage if you can swing it. Better machine/better components/better duty cycle/better heat. Better resale price if you decide you don't like welding & want to sell it. Ditto on at least MIG/Flux ability ... just make sure you set the polarity right if switching. You can play around with it on 110 & when needed/wanted, move up to full time 220 either with a genny or dedicated 50 Amp circuit. You'll be less frustrated & learn quicker.

Also, see if your local community college has night classes in welding. Sign-up, take the classes, see if you like it. Then check out what machines they are using & talk to folks you meet there about what they have/like/dislike.

alexpops · Jun 28, 2022

If money is an impediment to getting a better wirefeeder, don't overlook stick. A little steeper learning curve, BUT ... if you learn stick, jumping over to MIG/Fluxcore is a LOT easier than vice versa. I'll bet most folks (over 50 at least) learned on Lincoln buzz boxes before moving on to better welders/processes.

/pine · Jun 28, 2022

ray66v said:
I agree that you should try to buy a 220v welder.

You will probably use it more than you think, and be glad you did.

As far as welding 1/4" with a 110v welder, yeah, it can be done. If you bevel the edge, or heat the metal first, you can do it on a limited basis. But, it's more like work.

The other problem you'll have welding heavy material, is the duty cycle. It's only going to run on full power for a limited amount of time. Seems like as soon as you get enough heat in the metal to start to make a nice weld, the automatic shut down to keep from overheating kicks in. That's the other reason you want the bigger machine.

Flux core wire splattering is a bit too much for me. So, I like using the shielding gas. But, flux wire does have an advantage if you're welding outside.

This is a myth...(it's prudent to bevel the edges regardless of the welder IMO, no need to preheat the metal unless it's really cold) welding 1/4" mild steel is a breeze with a quality 110V welder...it generally takes two passes but if you take your time you will get decent penetration...
FWIW...I have pretzeled a couple of different fabrications with 1/4" welded with a 110V Hobart welder where there was no sign of the welds failing etc...I have crushed 1/4" angled gussets that folded like an envelope with no weld failures...

GeneV · Jun 28, 2022

jaxs said:
Gluing metal together with molten wire fall's way short of permanently joining it. You can melt filler on 1/2" metal with a 120 volt machine but that doesn't qualify as "welding it",regardless what buds on the web claim. Very few homeowner/diy projects exceed 1/4" so if 120 volt wire welder was suffecient,there would be little to no market for Hobart Handler 190 and similar machines that are so popular. It's difficult at best for newbies without people encouraging them to start off with machines that severely limit their ability.

A 220v machine is great coz it has a higher duty cycle and you're not tripping breakers, BUT...it's a bs statement to say a homeowner doing usual diy homeowner projects can't get things done with a FC90 or whatever. If that's what you're saying, your that "bud on the web".

And btw, although we're talking flux core, but I just finished a brush forks project, and welded all of it on my dual volt stick....using the 120 in my garage, just because. Never even popped a breaker.