corten steel welding

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aucklander

472 posts

Ultimate Geek

#303833 13-Mar-2023 10:12

Hi all,

I am looking to get into corten steel work which will also involve welding. Mainly, will get laser / plasma cut items 2.5 - 3mm thick from specialized shops which then get assembled in various items. I only have an arc welding machine at this stage (old transformer) and I read that electrodes 7018 would be suitable for this work (they work in AC mode). Structural strength is not a criteria, it is more important to get the welding weathering the same colour with the base material. I do not find myself satisfied with the quality of my manual arc welding skills and I am looking to switch to a MIG machine for this purpose. There are multiple sources advising that arc welding is harder to master than MIG, so changing to MIG might lead to an improvement of the quality of my welds?

I am looking at gasless MIG machines so I do not have to get / store / refill high pressure cylinders. I see there is gasless wire for mild steel and also for stainless.

My question is: do you know of any gasless wire for MIG welding suitable for corten steel please? Corten is "low alloy", not mild steel, but it is not stainless either... The supplier needs to be in NZ so I can obtain pricing and create a budget for this "upgrade" from manual arc welding to gasless MIG.

Thank you.

Ge0rge

1709 posts

Uber Geek

Trusted

#3049494 13-Mar-2023 11:21

Initially, just curious as to why you have written off using shielding gas?

Generally, you'll get a nicer weld with shielding gas, and wont have the same post-processing requirements that flux core has. And, as you have not doubt already seen, you get a wider variety of filler materials to work with.

The storage requirements for shielding gas are pretty minimal too, especially in a home environment - most people don't think twice about where their BBQ cylinder is stored, nor just putting it in the boot of the car and popping down to swap it - inert shielding gas is significantly safer in that regard. Not sure of your location, but have you seen EziSwap? It's pretty much swap-a-bottle but for industrial gasses - makes good sense if you are not churning through projects.

I'd also consider where you would be doing the welding - if you're inside then a shielding gas works well. Outside with any sort of breeze, then shielding gases tend to get blown away and leave you with porosity and other imperfections. Flux core tends to produce significantly more by-products so do be very careful if doing this indoors, conversely it isn't as affected by the wind so can be done outside without too much issue.

Lastly (for now, at least), the MIG process is reasonably easy to pick up but no easier than arc to master. As you already have yourself an arc welder, you could consider putting the money for a MIG towards more electrodes and get burnin' rods - the best way to become better!

Sorry to not have answered your question though! I would suggest giving Global Welding Supplies a call as they will probably be able to point you in the right direction - I have always found their service to be really good.

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

aucklander

472 posts

Ultimate Geek

#3049508 13-Mar-2023 11:44

Thank you for the quick reply,

I am in Auckland and I know about that supplier, I actually got stuff from them very recently (some shaded lenses, etc). The reason I am looking at gasless is because I see these MIG welders are lower cost (starting $310 at Bunnings) and I also do not have to buy the bottles. On the other hand, I see on Facebook Marketplace Argon bottled 7m3 (the big ones) brand new and full for $300 - $400, which you then only refill. But transporting these bottles horizontal in a small trailer might not be acceptable? I have no idea how much the small bottles could cost, tried BOC website but they require you to have an account even to give you a price. I will try the one you mentioned.

My biggest issue with arc welding is that I get lots of slug inclusions in the weld, which I then need to grind, redo, and so on, until I get all the cracks filled in... pretty tedious and not rewarding process... as you say, I should persevere and try to see what leads to an improvement and what not.

I am looking only at work indoors (garage / workshop environment).

Ge0rge

1709 posts

Uber Geek

Trusted

#3049531 13-Mar-2023 12:15

No problem.

Being in Auckland should give you several options for getting gas. You're right that BOC are more for the commerical user - that's why the likes of CoreGas and EZIGas have become a thing - catering towards the occasional/home user, and not requiring the annual bottle rental fees. Boc will rent you a D size bottle for $149 a year, and that cost includes one fill.

Personally, I'd be very suspect of buying welding gas from Facebook, but that's just me.

Depending on the amount that you are intending to weld, I probably wouldn't look at getting a G size bottle for home use - I'd be more looking towards the D size.

It's only really acetylene that should not be transported on it's side, argon / CO2 is fine laying down. Also, a D size bottle will fit easily in the boot, no need for a trailer.

Flux core mig also can have slag inclusion issues - this is certainly a technique thing. What position are you welding in? Also, are you "dragging the slag" - as in, are you pulling the stick and arc in the direction of the weld, as opposed to "pushing" it in the direction of travel? This goes for flux core as well, and goes a long way to stopping inclusions.

I'd also suggest, funds dependent of course, in getting a MIG that can do both processes - buying a cheap welder that can only do flux core might be quite annoying later on if you decide to trying shielded, or look to get a spool gun and try aluminum.

pipe60

119 posts

Master Geek

#3049604 13-Mar-2023 14:18

Bunnings do a good deal on mig gas, no rental.

https://trade.bunnings.co.nz/trade-services/trade-n-go-industrial-gas

tweake

1037 posts

Uber Geek

#3049684 13-Mar-2023 18:10

first thing, flux core welders. friends don't let friends buy fluxcore welders. fluxcore welders are simply the cheapest nastiest mig with all the useful features removed. yeah they are just crap. save your money and time, and stick to something decent.

as mentioned above, stick welding is not that hard. mig is actually more complicated. i recommend stick welders for beginners to learn with. that way they learn how to weld, not just weld bird poop and think its welding. if your buzz box is a decent one, then stick with it. it will work just fine for that sort of project.

if you go for a mig, you need to spend $700-1000 minimum on a machine. which is an okish entry level machine. migs also run fluxcore. keep in mind fluxcore wires can be temperamental beasts.

not sure with welding corton for looks. i might have to look that up.

edit:

https://www.globalweldingsupplies.co.nz/range-page.php?sku=R_WE8018W2

tweake

1037 posts

Uber Geek

#3049687 13-Mar-2023 18:17

aucklander:

My biggest issue with arc welding is that I get lots of slug inclusions in the weld, which I then need to grind, redo, and so on, until I get all the cracks filled in... pretty tedious and not rewarding process... as you say, I should persevere and try to see what leads to an improvement and what not.

I am looking only at work indoors (garage / workshop environment).

if your screwing that up, you going to screw up every other bit of welding to. i'm picking your using 6013 4313 "general purpose" rods which are bad for it. its just a matter of running enough amps and getting that drag angle right and blowing that slag back. it just takes practise. 7018's are a little different, got some quirks.

learn to stick weld and all other welding becomes much easier. very common for people to start with mig and end up bad welders because they have never welded good. start with stick.

aucklander

472 posts

Ultimate Geek

#3051117 17-Mar-2023 10:29

tweake:

if your screwing that up, you going to screw up every other bit of welding to. i'm picking your using 6013 4313 "general purpose" rods which are bad for it. its just a matter of running enough amps and getting that drag angle right and blowing that slag back. it just takes practise. 7018's are a little different, got some quirks.

learn to stick weld and all other welding becomes much easier. very common for people to start with mig and end up bad welders because they have never welded good. start with stick.

you are right, I am using 6013 electrodes as they are marketed "general purpose" and "best all-rounder", etc... considering I am looking to do corten steel, various sources indicate 7018 would be suitable as it weathers to same colour (or very close). Would you say changing to 7018 would help me get better results for mild steel too? Or what other electrode would you use or recommend for the "general" work (instead of 6013)? Thank you.

aucklander

472 posts

Ultimate Geek

#3051120 17-Mar-2023 10:42

I would go up to $200 - $250 on this one, looks decent for entry-level?

https://www.trademe.co.nz/a/marketplace/business-farming-industry/industrial/manufacturing-metalwork/welders/listing/4030636494?bof=ptRp0kHB

gas & gasless (but no stick welding too, as other machines have). I will need to get separate bottle and regulator. Use existing auto darkening helmet (fixed shade no.11). Lots of info on internet about this machine (USA, UK, South Africa) but nothing in NZ... It was GBP200 in UK (approx NZD300) so it is low-budget even new but is not available anymore. Not sure what the story is with the tape near the gun? Maybe crack / gas leak?

also - it has better load factor than many others (74A @ 60% and 60A @ 100%). It is transformer type, not inverter. Total weight 35kg. Pretty massive I would say...

gbwelly

1206 posts

Uber Geek

#3051127 17-Mar-2023 11:06

tweake:

learn to stick weld and all other welding becomes much easier. very common for people to start with mig and end up bad welders because they have never welded good. start with stick.

This is the correct answer that OP doesn't want.

tweake

1037 posts

Uber Geek

#3051170 17-Mar-2023 12:31

aucklander:

I would go up to $200 - $250 on this one, looks decent for entry-level?

https://www.trademe.co.nz/a/marketplace/business-farming-industry/industrial/manufacturing-metalwork/welders/listing/4030636494?bof=ptRp0kHB

complete garbage, avoid.

tweake

1037 posts

Uber Geek

#3051175 17-Mar-2023 12:42

aucklander:

tweake:

if your screwing that up, you going to screw up every other bit of welding to. i'm picking your using 6013 4313 "general purpose" rods which are bad for it. its just a matter of running enough amps and getting that drag angle right and blowing that slag back. it just takes practise. 7018's are a little different, got some quirks.

learn to stick weld and all other welding becomes much easier. very common for people to start with mig and end up bad welders because they have never welded good. start with stick.

you are right, I am using 6013 electrodes as they are marketed "general purpose" and "best all-rounder", etc... considering I am looking to do corten steel, various sources indicate 7018 would be suitable as it weathers to same colour (or very close). Would you say changing to 7018 would help me get better results for mild steel too? Or what other electrode would you use or recommend for the "general" work (instead of 6013)? Thank you.

nothing wrong with 6013. like all electrodes/wires etc they all have to be used correctly.

7016 is commonly used here as an allrounder. 7018 is also fine as an allrounder. i also use 6011 quite a bit when welding on rusty crap or galv. they all have their uses and are all different to run. thats why stick is really handy, you can do a lot of different stuff with one basic machine (and then there is stainless etc).

6013 there is a lot of variations. uphill/downhill can be tricky.

7016/7018 the biggest pain is you need to clean the tip before striking (few ways of doing that). its a lot nicer for doing multi pass welds with.

aucklander

472 posts

Ultimate Geek

#3063224 13-Apr-2023 13:08

Hi all, here is an update: I got a machine (second hand for $250) brand ROYCE, it also says on it MIG-MMA-600 and it takes gas too when I will have the setup for this, apparently it is max 600A which is way higher than most other machines I see around (which are usually going only up to 150A - 180A) and they cost $700 - $800 or much more; On the other hand, it is heavier (9.5kg) as opposed to the 180A machines which I see they weight around 4 kg and some even less, so I believe their claim for 600A might have some backing? Not that I will ever need that high amps. Has 10A 3-pin plug but I have a 32A circuit in the garage for the old transformer and will have to make an adapter to plug into that.

The machine is same as this one: https://www.facebook.com/marketplace/item/948067953031842/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3Aaff0c930-7da6-40e1-8ae7-68b3834ca287

but interestingly, I cannot find any information on internet about this exact model number, apart from quite few entries from suppliers in... Kenya?

The menu allows selection between MMA, MIG and something else called "TIG Lift", function I do not see on many other similar machines, so this might be an indication this is not really at the bottom of the range in terms of functionality?

As it was advised by others above, I will still focus on improving the stick welding skills and technique, but using this DC machine as opposed to the old transformer. All opinions I came across (various articles on internet) point towards DC stick welding being way better (it would ensure better results than AC stick welding at the same level of skill). I also got my corten steel parts which I need welding (2.5mm plates) and the 7018 electrodes (2.5mm), really looking forward to the moment when I will feel confident to get a start on that. Then I was told that actually 8018-W is better for corten, that's a different story... Trying to source that now.

When I got this MIG/MMA 600A welder (yesterday) it already had a spool of flux cored mild steel wire 0.9mm in it so this was the first test I run. I just selected few different settings to better understand how they impact on the weld and did some trial runs on clean no-rust mild steel plates using different V and A settings, and the bottom line is that I managed to get the best welds EVER (when compared to what I generally got from the stick weld with the old transformer). It looks promising.

Can the MIG gun be left there to avoid the trouble to remove the wire, then feed it again when you need to use the gun?

I am really keen to get the operating manual for this machine, if anyone can help it would be much appreciated. I have emailed a couple of people selling this machine (one on Marketplace and one on TradeMe, could be the same?), I will see if they are willing to help. Mainly, I expect the manual to take out some of the guessing out of the process, when it comes to setting the parameters.

I would like to be able to use the MIG for the 2.5mm corten steel rather than stick, but all MIG wires I see for this purpose require gas, none of them is flux cored. And they are fairly expensive. So I will focus on stick welding and see how far I can improve that. All welding will be on the exterior point of a corner join, then sanded with a flap disk. Imagine you use plates welded together to create a cube, all welding will be at the joints between the faces. I am not building a cube but this is the best description of the welding I will have to do. I will keep looking for options on getting gas and regulator and see how costs add up.

tweake

1037 posts

Uber Geek

#3063290 13-Apr-2023 17:06

aucklander:

Hi all, here is an update: I got a machine (second hand for $250) brand ROYCE, it also says on it MIG-MMA-600 and it takes gas too when I will have the setup for this, apparently it is max 600A which is way higher than most other machines I see around (which are usually going only up to 150A - 180A) and they cost $700 - $800 or much more

what you have is your typical fake welder.

a 600 amp welder is a huge 3 phase commercial machine, not one that has a 10amp plug on it. 10 amp machine top out at about 160 amps, cheap ones 140 amps. what they do is simply rig the display to show higher values. you would have to some tests and compare to other welders or use an amp meter to work out its actual spec.

you won't need a manual, there is not exactly a lot to them. the manual has little to do with the settings.

the lift tig might work, but they are often so bad its not worth using. even the stick side can be a bit touchy. the machines are migs with stick/tig tacked on to it. plus tig is a big leaner curve that you want to learn on a good machine rather than be fighting a poor machine.

Ge0rge

1709 posts

Uber Geek

Trusted

#3063316 13-Apr-2023 19:20

tweake:

aucklander:

Hi all, here is an update: I got a machine (second hand for $250) brand ROYCE, it also says on it MIG-MMA-600 and it takes gas too when I will have the setup for this, apparently it is max 600A which is way higher than most other machines I see around (which are usually going only up to 150A - 180A) and they cost $700 - $800 or much more

what you have is your typical fake welder.

I'm afraid tweake is correct, and you have been had.

By way of example, the big machine at work will produce 500A when you wind it up to "Chernobyl". When it's doing that, it will consume just over 24kVA, and it weighs in at a fraction over 110kg. Note that this doesn't include the wire feed mechanisim, this is just the power supply.

SomeoneSomewhere

1107 posts

Uber Geek

Lifetime subscriber

#3063323 13-Apr-2023 19:38

To be fair, that is a 15A plug, not a 10A plug. Although the listing says it's 16A, which is not a good sign. Machine is good for maybe 200A (at like 5% duty cycle)

Lies, damn lies, and cheap rubbish.