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re-tarded
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some cast steels are perfectly weldable with MIG but "cast steel" encompasses a wide range of materials

I'm surprised at your statement of 70% the travel speed, I would've guessed more like 1/3 to 1/2 in most cases. this of course has a big impact on gas consumption.

I agree that cups last forever if you don't throw them around, and tungstens last a VERY long time. a 1/16 tungsten costs a couple bucks and unless you're really awful you won't manage to go through it in a solid day's welding... and once you're better, it'll be way less than that. not enough cost to worry about vs gas (the big one), filler, power, etc.

for MIG to do stainless and have it stay stainless you need the right gas too, which is way more money than most gasses


I agree that the big one is the learning curve: with an hour or two of training, someone good with their hands can lay down somewhat tolerable MIG. the same with TIG will take at least several times as much training.
 

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Fuck it, let's do it live
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some cast steels are perfectly weldable with MIG but "cast steel" encompasses a wide range of materials

Generally speaking, castings really need a filler with a high nickel content. I've used 308L in a pinch. Yes, you can MIG it, just doesn't usually hold up too well.


I'm surprised at your statement of 70% the travel speed, I would've guessed more like 1/3 to 1/2 in most cases. this of course has a big impact on gas consumption.

I mean it's heavily dependent on the job of course... fitup, joint type, position, etc. But yeah, it's not that crazy of a number. Most people run too slow with TIG.

I agree that cups last forever if you don't throw them around, and tungstens last a VERY long time. a 1/16 tungsten costs a couple bucks and unless you're really awful you won't manage to go through it in a solid day's welding... and once you're better, it'll be way less than that. not enough cost to worry about vs gas (the big one), filler, power, etc.

for MIG to do stainless and have it stay stainless you need the right gas too, which is way more money than most gasses

You're right, I forgot about the gas. Same with aluminum. You'll want straight argon for both... most MIG tanks are filled with C25 (75% argon/25% C02). Expect to pay 1.5-2x the cost for straight vs C25.

I agree that the big one is the learning curve: with an hour or two of training, someone good with their hands can lay down somewhat tolerable MIG. the same with TIG will take at least several times as much training.

I'd say getting the basics down is pretty close to the same between both of them. The difference is with MIG that's all there is, with TIG you've got a lot of finesse and muscle memory to figure out to get from basics to making pretty welds.
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re-tarded
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lots of people MIG stock LS exhaust manifolds for turbo applications and I rarely hear of problems, but I'm sure there are also plenty of alloys where it won't work for shit

I thought stainless MIG generally involved a trimix gas, but haven't done it myself. I don't see *that* much of a cost difference between C25 and Argon: the latter is maybe 20% more expensive. It's the trimix, with helium, that's expensive.
 

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Discussion Starter #24
thanks for the comprehensive responses guys. in all likelihood i may not be welding much beyond the current slow build. most likely going to use only for under tray, wiring and battery box...the odd bracket. i think if i were going to be into this for the long run then i would go with TIG but as i am only going to use it a handful of times maybe MIG is winning out? then the question is going for a new rig...about £170 or going for a used example with varying prices. hmmm....
 

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re-tarded
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at that budget I'd 100% go used.

I picked up my Lincoln 175HD, with a gas bottle, for $225. anything you can get new for that price will be awful quality, and then you'll need to buy/rent a bottle too.
 

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Is my bike ok?
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That's just because you're slow.


I have a few thoughts on this...

A good TIG welder can run around 70% the speed of a MIG welder.
But really, speed shouldn't be a huge concern for anybody here. None of us are running production shops and tracking parts-per-hour, in this space it's about quality over quantity IMO. If a weld takes 10 minutes instead of 5, but looks way better... so what?

You can usually get away with running a bit less gas flow than with MIG. The weld heat is more concentrated and the part shouldn't be getting as hot as with other welding processes, and the slower travel speed means you have direct gas coverage over the specific area for longer.

Also re. speed... you have basically zero cleanup. No spatter to scrape/grind off, nothing catching on fire, etc. so the overall time spend from prep to cleanup is pretty close.

TIG allows for things like fusion welding where you don't use filler. Not always appropriate, but sometimes a good option and will save you the cost of filler if you are worried about that.

Less consumable costs, because less consumables. TIG cups are non-consumable vs. MIG cups which do wear down from repeated spatter and clean-up. Electrodes (tungsten) don't wear unless you fuck them up by dipping them or running too hot for the size, vs. MIG electrodes which wear out from burnback and just friction. The only actual consumables you have with TIG are the filler and the gas.
Not breaking shit is pretty easy too... just make a nice littler holder to hang your torch on and itll be nice and out of the way. But yes, tungsten is a brittle metal and TIG cups are class or ceramic, so they aren't as agreeable to being used as a hammer as a MIG gun is.

The learning curve is steeper, but not insurmountable by any means. Look at all the goons that have figured it out... if we can do it so can you. The thing about it is that TIG is a proper skill, while a trained monkey can run a MIG.

TIG isn't picky about weld prep. Materials are. You can weld picky materials with TIG, which is why it gets that rep.
With mild steel specifically, quality vs. cleanliness is a product of the filler rather than the process. Most mild steel filler you'll find for TIG is ER70-S2, most wire you see for MIG is ER70-S6. The S6 has more silicon and manganese, which helps the puddle flow better and more importantly helps carry contaminants out of the weld (the silicon does this, it's the glass stuff that develops on top of your weld). Buy some S6 filler rod or just use some lengths of MIG wire and your mild steel TIG weld will be as un-picky about prep and cleaning as your MIG is.

TIG can weld:
- mild steel
- stainless steel
- cast iron & cast steel
- aluminum
- titanium
- Inconel
- Hastelloy
- magnesium
- ceramics
- etc.
It also opens up the world of TIG brazing. You can join any metal to any other metal this way, even if they aren't weldable alloys.

MIG can weld:
- mild steel
- stainless steel, but not very well and only IF you buy a full spool of stainless filler
- aluminum, IF you have a push-pull gun and the right machine
Can also kinda-ish weld cast iron and cast steel, but not very well and it WILL break eventually unless you have special filler wire.



Get a TIG.
All welders need special filler wires/rods for certain alloys, so that's not a plus or minus for any machine. Matching filler rod to parent metal is just part of the welding process in general.

And yes, I am slow! But there's science and physics and shit at play :D I can't make metal wet/flow any faster than it's gonna just because I've decided I'm a good welder.

And you don't really need a special gun to weld aluminum with a MIG. Wire feed welders were invented because of aluminum welding. It was their main reason for existing. Since aluminum filler consumes so quickly it was a huge pain in the ass trying to weld with rods, so they developed the fed spools of wire. Keep those factory workers pumping out products.

The spool gun is just to keep the filler wire clean of other filler wire's left behind dust ( I know you know this, Mac). But not all MIG machines weld aluminum nicely- gun or not- it's just not that cut and dried. My MIG won't do aluminum worth a shit, my buddies welder lays out beautiful aluminum beads. There's so many in's and out's to welding machines...I'm not smart enough to know it all.
 

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Fuck it, let's do it live
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All welders need special filler wires/rods for certain alloys, so that's not a plus or minus for any machine. Matching filler rod to parent metal is just part of the welding process in general.

And yes, I am slow! But there's science and physics and shit at play :D I can't make metal wet/flow any faster than it's gonna just because I've decided I'm a good welder.

And you don't really need a special gun to weld aluminum with a MIG. Wire feed welders were invented because of aluminum welding. It was their main reason for existing. Since aluminum filler consumes so quickly it was a huge pain in the ass trying to weld with rods, so they developed the fed spools of wire. Keep those factory workers pumping out products.

The spool gun is just to keep the filler wire clean of other filler wire's left behind dust ( I know you know this, Mac). But not all MIG machines weld aluminum nicely- gun or not- it's just not that cut and dried. My MIG won't do aluminum worth a shit, my buddies welder lays out beautiful aluminum beads. There's so many in's and out's to welding machines...I'm not smart enough to know it all.
You're not wrong re. having the right filler. The difference is that with MIG, stainless and alum are far less common than the various flavors of mild steel filler wire available, and between that and the amount you have to buy it in (because it's a spool instead of a few sticks) it ends up being more expensive than running a different metal with TIG.

Amperage, gas flow rate and type, tungsten grind angle and truncation, tungsten size, standoff from the weld, etc. all play into it. Run hotter, lets you move faster, lets you weld for less time, lets you use less gaas.

I don't know of the history of wire feeders, but contamination from other metal in the hose liner is only part of it. The larger issue is that aluminum is generally too soft to be pushed through a long MIG hose, so you either have a spool gun where the spool is, obviously, on the gun (I hate these), or you have a push-pull gun with a dedicated hose that does what it sounds like.
 

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Fuck it, let's do it live
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@remfanuk buy used, no question. Zero reason to be buying new, you'll be far better off getting a better used machine than a shitty new one.
 

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re-tarded
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Cast metals in general are weldable.

Cast iron is a pain in the ass because it's iron, not because it's cast.

Cast aluminum welds very easily. Cast steel seems pretty much the same to me.
cast is typically dirtier than extruded or cold rolled, and there are alloys that can't reasonably be welded (as is true of extrusions/rolled)
All welders need special filler wires/rods for certain alloys, so that's not a plus or minus for any machine. Matching filler rod to parent metal is just part of the welding process in general.

And yes, I am slow! But there's science and physics and shit at play :D I can't make metal wet/flow any faster than it's gonna just because I've decided I'm a good welder.

And you don't really need a special gun to weld aluminum with a MIG. Wire feed welders were invented because of aluminum welding. It was their main reason for existing. Since aluminum filler consumes so quickly it was a huge pain in the ass trying to weld with rods, so they developed the fed spools of wire. Keep those factory workers pumping out products.

The spool gun is just to keep the filler wire clean of other filler wire's left behind dust ( I know you know this, Mac). But not all MIG machines weld aluminum nicely- gun or not- it's just not that cut and dried. My MIG won't do aluminum worth a shit, my buddies welder lays out beautiful aluminum beads. There's so many in's and out's to welding machines...I'm not smart enough to know it all.
a spool gun also feeds better: since aluminum wire is soft, you're more likely to have feed problems in the liner.
You're not wrong re. having the right filler. The difference is that with MIG, stainless and alum are far less common than the various flavors of mild steel filler wire available, and between that and the amount you have to buy it in (because it's a spool instead of a few sticks) it ends up being more expensive than running a different metal with TIG.

Amperage, gas flow rate and type, tungsten grind angle and truncation, tungsten size, standoff from the weld, etc. all play into it. Run hotter, lets you move faster, lets you weld for less time, lets you use less gaas.

I don't know of the history of wire feeders, but contamination from other metal in the hose liner is only part of it. The larger issue is that aluminum is generally too soft to be pushed through a long MIG hose, so you either have a spool gun where the spool is, obviously, on the gun (I hate these), or you have a push-pull gun with a dedicated hose that does what it sounds like.
you can get away with running it in a normal MIG setup if the liner is in good shape and you're especially careful about avoiding tighter bends on the lead

I can't imagine anyone here has experience with pushing rope ;)
 

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Discussion Starter #32
wow...lots of stuff i know zero about...but great to hear the different arguments. thanks guys. used MIG then eh.
 

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Discussion Starter #33
Quick question...solid slugs or will similar diameter tubing be sufficient as long as its around the same thickness of the original.

Sent from my SM-G960F using Tapatalk
 

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No spatter to scrape/grind off, nothing catching on fire, etc. so the overall time spend from prep to cleanup is pretty close.
I don't know what you are talking about :fu:
 

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Discussion Starter #36
i am struggling to find tube at the usual UK retailers (RSm metals4u, metal mania)...so for the frame slugs i am looking at using tubing which is what came from the factory. so, the top rail is 3mm wall thickness and would take an outside diameter of 28mm. the bottom rail/support is 2mm wall thickness and needs to be 24mm outside diameter. are these odd sizes?

could slightly larger outside diameter tube be slit to reduce its diameter or will that just fuck its strength up?

any other sources you UK guys can point me towards please? any other advice appreciated. thanks
 

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hooligan quads
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it worth looking into pipe instead of tube. i have found both the XJ i did a few years back and the bandit the OEM metal used was closer match to pipe than tube, for inserts then you can use tube. example pipe is 25mm ( pipe is measured ID) tube 25mm (measured OD) works well
 

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stupid question time...what is the difference between pipe and tube?


Tube is measured by it’s OD. Pipe is measured by it’s ID.

Later, Doug
 
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