Im a fabrication n00b and I was wondering what the major difference is between flux core welding and true MIG welding? Is the only difference the sloppiness of the welds? Are the welds still reliable and can stand up to high heat (aka downpipe/dumptube temps) with flux core? What are the major downsides to flux core?

Thanks for any help

 

The welds aren't any worse for a flux core vs a GMAW weld if you know what you're doing. 99% of the people on this site don't know what they're doing with a flux core machine, so thats why it always looks like ****.

 

ok so if done right flux can look decent, but what about reliability/heat resistance and stuff??

I am trying to flux a complete 3" downpipe for my daily driver and i want to make sure the welds will last and such

thanks

 

I totally agree with k24em2

flux can look just as good as gas welding its just that people on this site give it a bad name cause they dont know how to use it right.....

flux core, like any form of welding, is strong if you do it right.

for your 3inch downpipe. as long as the fluxcore machine is pretty strong it should have no problems making reliable welds.

obcourse though im not saying that flux core is better over all than gas mig welding.... in strength they can be the same depending on the machines... but overall i would take a gas mig welder anyday. just cause its much easier to work with than flux core.

 

I agree with everything said so far and I'll add that it's partly due to the fact that most fluxcore welds done on this site are with harbor freight pieces of poo welders. The results are not what one might achieve with a better machine.

Yes they will be strong enough. THe one thing 110 volt flux core welders are good for is hacking together stock mild steel exhausts and random stuff like that.

 

flux core is pretty much the standard for heavy manufacturing. My instructor works for Caterpillar they only use FC or FC w/ gas. Also, just about every piece of equipment I've ever seen on a construction site is FC - from concrete trucks to pile drivers to bulldozers (repairs or hardfacing is done with stick, but factory welds are all FC)

if you notice the welds, you'll see a very steep V pattern indicative of the high heat of FCAW and a flat bead with deep penetration. As stated above, FC has a bad rep because it's entry level and noobs expletive up and blame the process instead of their skills

 

ive been FC'ing for about 2 years...im getting decent at it. I completly agree with Bjorn on his last sentance. All my FC welds have held and they are strong. I really didnt start to get good until a tooking a MIG course at my school. That def. helped with the technique.

 

I picked up a Lincoln SP-135 (110v mig/fc) the otherday, came with .035 FC and .025 mig wires. I'm getting gas soon, but for now, I'm rockin the FC ****. I'm actually laying some good beads [for never welding before] - some look better than some MIG welds I've seen here and on other's cars. No antispatter, hold-in-hand mask, rusty wire brush - the most basic of tools. I've never welded before, and all my test welds pass the 'throw on ground'/'bang with sledge' tests. The small stuff is hard with .035, but that's to be expected. I wish I could personally compair it to MIG, but I can honestly say with a good machine and some research on how to work it, I'm doing better w/15mins of FC welding experience than others with cheap machines who've gone through a few MIG spools.

The deal is the flux shields the puddle, and just creates a mess more than anything. If I had a nice wire wheel, I wouldn't have much of a problem with it. Anyways, I think I could agree with the el-cheapo welder machines. I felt since my two DIY jobs would otherwise cost me a good $450+, $600 in welder/tools/materials is one helluva deal.

 

This sort of thinking makes me question if you guys would ever want to stick weld? It is totally possible to make strong, full penetrating and beautiful welds. It comes with:

1. Speed
2. Angle
3. Temperature

If you watch your puddle then you will be able to define your finished product.

1. Speed will help with pool size, heat effected area and penetration (also your fitup is key).

2. Angle will help with where your slag will end up. You can watch your puddle and send your filler down and the slag (slightly darker waste in the puddle) towards the back of the weld. Keeping your waste behind you and your filler in contact with you base metals.

3. Temp or heat will help with the speed you have to run and merging of the metals.

I have mig and tig at work but we don 75% of our welding with stick. It just makes sense. I would love to do garage work where it was all mig and tig.

Also if you want to test your welds hammering is cool and so is dropping.

I would suggest taking a sawzall or wafer wheel and cutting your base metals and weld bead. If the weld went east to west cut north to south.

Check that the three metals are now one. You shouldn't see the two metals and your weld in there like "glue".

I went thru an intense class at work for welding and still have my books. I am more than happy to help anyone with their questions.