Been doing stick welding for a bit, but when it comes to thin steel such as on cars, sticks blow right through.
I was thinking about getting a flux core machine to do some exhaust work on my car because I don't want to mess with gas.
What should I know about flux core? What are the biggest cons about it?
Flux core is messier but easier and with practice you can do pretty well. Get a machine that allows you to switch to gas for when you get better or when you require better work/finishing
Flux will leave welding spatter on everything around it, you can reduce this to an extent by switching the polarity of the welder sometimes (look up which way it needs to be so you don't make it worse). Just buy a few cans of welding prep spray, it's a coating that prevents the small bits of hot metal from sticking, so can be wiped away. That said I think flux core tends to give better penetration with bad prep, so perfect for auto stuff where you can't always get everything perfect.
If you do get a cheap flux core machine get a new(er) inverter one, not a transformer one. Inverter welders weigh a fraction of transformer welders, and should allow for continuous amperage/voltage control rather then the discrete high/low settings you get on cheap transformer welders.
I wouldn't bother getting a gas capable machine as suggests, just get a decent no gas machine and if you use it enough to warrant getting a gas capable machine you can just sell it on and get most of your money back, better than spending the extra on a feature you may never use.
Why do noobs consider gas a bother?
I don't. I service welders and most of my machines are industrial (love my Migmaster 250s arc on sheet metal). FCAW is ghetto on car sheet metal compared to gas.
OTOH gas conversions to many cheap machines like my old copper winding Weld-Pak 100 (bought used to convert because excellent arc) are cheap and very low effort.
Gas intimidates people who do it wrong but empowers those who use it wisely. I keep oxygen, acetylene, nitrogen (for HVAC but you can pressure test with MIG mix or argon as easily because I have), propane (for weedburner preheating and large oxy-LP rosebuds), argon and MIG mix in various cylinder sizes for dirt cheap because knowledge is power. When boomers die their estates sell cylinders cheap as do many small business auctions.
Are you supposed to attach the negative lead to the stick or to your work piece?
For stick AC it doesn't matter
For general welding DCEP (Direct Current, Electrode Positive) is standard.
Sometimes lower penetration is wanted so the operator may switch polarities to DCEN but I don't bother.
MIG is DCEP
Flux core is DCEN:
https://weldknowledge.com/2015/09/17/reason-why-some-self-shielded-fcaw-wires-are-recommended-dcen-polarity/
Plenty of exceptions exist so know what your task requires.
So, like I said, you have the polarity backwards. Watch this https://www.youtube.com/watch?v=IjmRDZPQios
Gas will make your welds 100% better almost instantly in my experience. You can get tiny shielding gas bottles for $150 or less through the exchange places like thoroughbred or gas pony. Exchanges are cheaper after you first buy the tank.
Wtf just get gas, it's not that expensive.
>What should I know about flux core?
That it's not for auto work.
>What are the biggest cons about it?
For auto work, that it's messy/spattery, and hot. Regular MIG is much better for that, in part due to having much better control on the low end for thin material.
>I was thinking about getting a flux core machine
>flux core machine
Which means it's so crappy that it's not made to handle gas in order to reach a price point below crappy MIG machines. Wirefeed machines can be finicky, and build quality matters. If you'll be doing actual work, get at least a halfway decent machine.
You probably have your polarity wrong
gas shielded MIG is the preferred welding method on cars.
Flux core sucks.
For exhaust you can also use Oxy/Acetylene and a fill rod aka metal coat hangers
>For exhaust you can also use Oxy/Acetylene and a fill rod aka metal coat hangers
OK boomer, it's not 1954 any more. Oxyfuel is literally only good for cutting and brazing and only sweaty tryhards and literal boomers will tell you otherwise.
Practice on scrap, remove corrosion using a flap disc and carefully fit all your parts. When you don't blow through scrap you'll be good enough.
BTW gas is not a problem. Stop thinking it's a problem. It's a great benefit especially for automotive work. There is nothing new to be discovered in welding. Copy success, adjust your machine on same-material scrap then do work when your results are reliable. Used cylinders go cheap. I exchange them at the welding supply and wallow in gas.
Many FCAW machines can be converted to gas. See the various videos. It's simple and cheap. Then use a gun with .023 solid wire. If you expect to DIY you'll want a non-shit welder. FCAW has its place outdoors on thick stock. Every process has its place so I equipped for the most useful (stick, MIG, TIG, FCAW with suitcase feeder for outdoor structural etc, resistance spot welding for auto body pulling studs) processes. Easy over time if you're observant so you can score deals.
Confirmed for never using oxyfuel because it's far from difficult. Use the correct filler or pieces of same steel as your workpiece. OA isn't remotely difficult and puddle control is easy. If all you have handy is brazing filler and flux that's amply strong and shock-resistant for downstream exhaust work. I used to braze steel rule style fabric cutting dies and the parent metal would often fail before a braze joint broke.
It's hilarous that unreasoning fear made OA gear cheap. I buy cylinders for less than the contents are worth and never run out on weekends. OA welds, brazes, solders cuts, anneals, hardens, gouges/scarfs, shrinks and flame straightens. No great skill required since I can do it and I'm not special.
I never said oxyfuel was hard, just that it's obsolete. If you've got a half decent SMAW machine you can set it up for TIG and be 100x better off than trying to be a sweaty tryhard and oxyfuel weld something. There's literally no reason to run oxyacetylene for anything, as oxypropane cuts and brazes just as fricking well for a moderately lower price and a significantly higher safety factor than oxyacetylene
>Oxyfuel is literally only good for cutting and brazing
Works decent for welding thin aluminum. The large, wide heat input reduces brittleness vs other methods.
do not use flux for sheet metal
a tank of c25 is only $100 usd and that is a deposit, you can get it back anytime however if you're doing a lot of work, it's the same price to refill the $100 tank as well as the $300 in my experience, like 35 for me
also if you're getting a harbor freight machine like it sounds, like dont frick with the .025 wire, go for the thicker ones idk if it's just their wire but the stuff just pops and burns back to the tip even on low heat
lower heat
If youre blowing through with stick on muffler thickness its your own damn fault. Mainly change your angle of attack. The stick should just melt and lay down on your work surface. Go look what a 20 degree angle of attack on a flat surface looks like.
1/16 inch 6013 electrode. No idea what amp setting because theres no amp settings. Its just 2 microwave transformers I wired into a box of shit.
If youre still blowing through at a 20 degree angle its because youre not running your bead fast enough or stitch welding like a 3rd worlder where you weld. Stop let it cool down then weld again.
No high level experience but I assume just blaming your tools and getting into new ones isnt some magic key to unlocking success and would just leave you chasing your tail.
>If youre blowing through with stick on muffler thickness its your own damn fault.
and it's nearly impossible which is why nobody does it, or they try it once and immediately realize it sucks.
>inb4 I can do it easily
Sorry. I have no idea what youre talking about because you huffed too many welding fumes. Another thing you can do is try to lay what youre welding flat on something heavier thickness if possible to get it to heat sink, like a welding table, that also helps to prevent blow through.
Remember Im working with a box of home made shit with no dial, so I just got to get good or get fricked.
That spear point and round are all catalytic shield thickness. The pipe is from a couch with a fold out bed so even thinner. I get tons of blow through all the time. So im the expert of blow through. Call me when you need me to cut something like a plasma cutter with a stick.
OP here
You are fricking moronic. I have tried 1/16 7018 electrodes with lowest amperage possible. That shit blows right through an exhaust pipe. The metal thickness that I was working with was 1-1.5mm and the only way you can "weld" something with an electrode would be just putting slag.
I already bought flux core machine and it is night and day difference. As other anons mentioned, it is spattery, but the slag inclusions are much easier to avoid and overall it is a much cooler welding method.
Including pic of my shitty first time weld of an exhaust pipe ( did a 30 angle and attached a flange)
>1/16
>7018
There's your fricking problem you moron. You use 6013 for sheet metal, 7018 has too much penetration
You can and I have but exhaust shops don't for good reason. The answer to welding problems is full process coverage.
Many online welding supplies exist and I use them too. Fastest shipping is often via Ebay stores and many auction buyers liquidate via Ebay because they get all sorts of stuff in heterogeneous loads.
Ebay search "E71T-GS .035" 0.9mm" for examples of that popular wire. Many 10lb spools for well under 50 shipped.
I live in the ass end of the middle of nowhere, and it takes literally weeks to get anything shipped out here. So I'll pay the extra at the farm store.
>shave before putting on a respirator
Frick off israelite
Apparently it was the reluctance of israelites to shave that resulted in Israel developing the first military gas masks that work with facial hair. Because yes, it does break the seal. If you're doing something where you should be wearing a respirator, you should probably be wearing it correctly. That means being able to pass positive and negative pressure tests.
I suppose I should have specified that you should pony up the cash for a real PAPR hood if you actually care about your health instead of being a cheap israelite and using a kn95 dollar store coof mask
A "respirator" in the context of fume protection usually refers to something like a half-face cartridge respirator, which is commonly used in various industries.
PAPR is superior and more comfortable, and costs about as much for the mask and apparatus as you'd be paying for a decent welding hood and a decent half face.
Also there's a million cheap israelites and misinformed morons out there who think a kn95 coof mask is just as good as a p100 dust mask, or even a genuwine half face respirator with associated filters
Also also, who the frick wears a half face canister filter under a welding hood? I've never seen a guy do that because they don't fit right. Everyone I know wears either a dust mask or a PAPR hood
I wear a full face respirator with welding lense attachment (and prescription lenses insert) at work. We have PAPR, but the company is moronic and panic pulled them after deciding they don't trust anyone to "properly" clean the filters from more hazardous materials like hexchrome, gouging residue, or lead dust. Instead they'll just go through red cartridges like candy and send countless respirators through a cleaning service every month.
sticks a fricking art.
but not for this pussy. Hes the proud owner of a brand new fancy ass flux core machine. Glad I could help tho.
But I seriously believe he was attacking with that stick at a 90 degree angle then yelling at me im a moron.
Honestly, as someone whos technique has entirely delveloped around having to mitigate the fact you cant adjust your machine in any way you should probably shut the frick up.
You may have found something that works for you, to be clear im not shitting on your ability to weld.
Im saying someone in your position should recognize where they are. Lurk more, post less. You shouldnt be shitting on others, mr. Microwave.
Flux core sucks ass for sheet metal. TIG is king, GMAW is a close second, stick is workable if you're not a moron and put a little effort into climbing that learning curve.
1. exhaust pipe is aluminumized steel
2. you can't weld rust
3. you have 0 penetration
4. those welds will break after the first winter
you will have significantly better results stitch welding with a $100 flux core MIG, but make sure to grind off the aluminum plating first.
>What should I know about flux core? What are the biggest cons about it?
It burns hotter than stick or MIG
This also means it can burn off contaminants and still get a good weld, if you don't blow a hole in your base material.
Please allow me to make a question about cars and welding. I don't want to start a thread for this and there's no QTDDTOT
first things first. I know nothing about welding. I used tin, nothing else.
so, in my head, thinking of welding a piece of metal on a rusted part of the car would end with an explosion because of gas/diesel ignition.
can someone pls explain? am I right or is it safe to weld on car?
As long as there's not a puddle of gasoline sitting under the car, and you're not welding on fuel components, you'll probably be fine. Keep an extinguisher handy and stay aware of your surroundings
could you elaborate? I want to understand why it doesn't explode.
In my mind, as someone who knows nothing about welding, there are two options.
a)electricity will hit the gas deposit and explode.
b)electricity will search the shortest way to the negative pole, so they won't travel around the car if you put it near where you are welding
>Forgets about the sparks
see
>first things first. I know nothing about welding.
Hey bro. For an explosion you need fuel+air+spark
A fuel tank has fuel, but not enough oxygen inside for a good fuel/oxygen mix, and will not get any spark to it. The grounding clamp that you need to put on the car to be able to weld is where the current is going to flow to.
If you were to empty the fuel tank and try and do welding work directly on it, then you risk an explosion. There will be an atomised mix of oxygen and fuel contained in the tank and you'll hit it directly with spark. That is why when doing fuel tank welding work you need to completely fill and empty the tank with water to displace all fuel gasses.
t. not a welder either, so take that with a grain of salt
>electricity will hit the gas deposit and explode
mysides
You probably need to flip your polarity. Even pros frick this up. https://www.youtube.com/watch?v=IjmRDZPQios
I use flux core on my shit boxes and I am very happy with it.
Sure its a little messier because of welding spatter but that stuff can easily be removed.
What I hate about welding with gas is that I usually run out of gas when I am in the middle on something. I usually work on my stuff on weekends/ at night and the stores are closed. It also takes about an hour to get new gas. Valuable time I dont have.
Flux core wire costs about the same like regular mig wire. I save a lot of money on skipping gas and I am happy with the results. I need to grind the welds anyway, so who cares about weld spatter.
>Flux core wire costs about the same like regular mig wire
Where the frick are you buying wire from? Hobart flux core is $90/10lb and gas shielded is $50/10lb at the farm store I buy my shit from.
That's literally the cost of a bottle swap in difference. It's cheaper to use gas after you get over the initial investment, and you get better welds to boot
Gas money is trivial. Used cylinders (never lease) are so cheap I often buy them for the cost of the contents and in consequence wallow in cylinders. CO2 is cheapest and runs hot, ideal for tiny welders but I keep 75/25 too.
If you keep two or more cylinders you don't run out. I don't and gas variety is based. CO2 cylinders hold much more gas (CO2 stores as a liquid) than MIG mix.
Local welding supply or online. Farm stores = rape. Auctions are always worth a look and I've thousands of dollars in TIG and MIG and FCAW filler that cost me hundreds.
Hobart E71-T11 goes about sixty bucks on Amazon for 10lb but I only use FCAW outdoors on roofs etc via my suitcase feeder.
How do you find places to get your cylinders filled? I can only find one place near me online, and they are really anal about which cylinders hey fill. Literally everywhere else only does rental cylinders as far as I can tell. Any ideas?
I know what neck rings my local Airgas will exchange (of course they do blank rings but those are all customer owned so I try to get one back. I also have another independent supplier who fills CO2 and MIG mix onsite.
I know what damage (severe corrosion, arc marks) disqualify a cylinder (easy to find online or ask the welding supply who should also list the brand cylinders they fill because the industry consolidated and companies bought each other many times since the early 1900s.
Welding gas supply quality varies so ask on Weldingweb posting your county to see if anyone knows who is good.
This app finds the big welding gas outfits who also requalify cylinders and are who locations which don't do that send their:
https://play.google.com/store/apps/details?id=gov.dot.phmsa.RIN&hl=en_US&gl=US
Most cylinders are NOT rentals but smaller than the largest sizes are frequently customer owned even if the supplier neck ring is fitted. The industry is so ancient that was unavoidable.
Best to visit each in person as some cut nice customers a break but wouldn't say so over the phone.
Where do you live?
Avoid Airgas, they're so overpriced
Sometimes they're the only game in town but gas fills are pretty much all I get from mine. Hard goods and filler are best bought online. My Airgas treats me well and they have considerable discretion to do so.
The crew running it at the time matter more than the parent company. I placed orders for our local welding school and over several years abandoned the indy shop because their service sucked then went with Airgas who had excellent reps but they somewhat declined.
I have cylinders suitable to either and of course CO2 can be filled anywhere.
Linde divested its bulk gas business to Airgas/National Welders so Linde, National Welders and related can be exchanged there.
Confused yet? Best way to be current is ask Weldingweb or the Miller forums or getting lists of what they fill from suppliers in person.
Yeah, I pay a premium at the farm store, but I also only have to drive 30 minutes instead of 2 hours one way
And frick giving bezos any of my money, especially when "free 2 day shipping" means a week at minimum
Flux core will kill you, wear a respirator. Stick might kill you too, wear a respirator. MIG on alloy will kill you, wear a respirator. Fumes from dirty metal might kill you regardless of weld process, wear a respirator.
Also shave before putting on a respirator, beard hair breaks the seal. You only have two lungs and they don't like giving people new ones. The respirator is easier.
Real welder here
lmao at all the armchair welders on here
listen up OP
>automotive welding
>short circuit mig welding with 75/25 gas
>wire diameter .025
>.030 also good
>mild steel alloy
and thats it