What type of Welder? stick? mig?

[toc]

Kind of off topic :) What sort of Welder would you guys recommend? I was thinking of a stick welder, because it looks slightly less complicated. I thought that mig welding needs some sort of gas bottle, but Im seeing gasless models at bunnings :shrug:

[astronobob]

Hi Tim,
Ive had a stick welder for about 15yrs now, it was affordable ! Ive never looked back, It has been awesome for what I use it for, Built a dozen trailors over the yrs, also built some wharehouse Frames for stock storing and a large steel framed workshop appox 7 x 4mtrs with benches etc, Plus lots of smaller stuff !

I find the advantage with a stick welder is they are cheap per inch of weld, prob atleast half, maybe a 1/3rd of a gas welder, Mig or Tig what have you, Plus stick welders are pretty much Maintainance free.

I won't be bias tho, Stick welders do have restrictions, like types of materials, mainly usable on good ol Steel, tho you can get sticks for Cast, Stainless and some Alloys, but they dont do a great job with these, but if your just working with steel, then they a great !

Migs, gasless & Tiggs very much do a much cleaner job, as they do Not produce the Slagg that stick welders do, which you have to hammer off, its a little extra work on bigger jobs but if your welds a good, the slagg comes with just a knock or two, !

Ive seldom used a tig, mig or gasless, so I dont know the ins and outs that well, tho I do know thay sometimes have probs feeding the wire which can jam if not carefully looked after & maintained ! Gass assisted welders also need attention every use, particularly with the nozzles that deliver the gas to the weld site, they need be clean all the time as the gass's main purpose is to create an enviroment for the weld burn. if its not delivered properly, it can be messy ! In saying that, A new welder of these type, would be fine for a fair while, tho it still need maintainance from day one, Only if they are neglected then many a problem will accure ! !

Hope this helps ,,

[mental4astro]

Bob's right about stick welding being very affordable.

There's some other things about the four main welding methods, oxy is the other:

* The area heated by an oxy welder is very large, stick is large, mig's heat area is smaller, Tig's is the smallest and also gives the finest control.

* All electrial three welding forms produce huge amounts of UV radiation. You need to make sure you are covered completely, eyes, face, skin. You need a welding helmet, not goggles, for these welding forms. Oxy doesn't produce the light or UV of electrical forms of welding, so goggles are fine.

* All four welding methods also require different darkness of the welding lens, oxy the least dark, Tig the darkest. You can't safely use an oxy grade lens to do stick. Likewise, Tig requires a darker lens than stick and Mig. You can get away with a stick helmet with Mig, but not recommended.

* Gas Mig and Tig require the use of Argon gas to isolate the welding process. Gasless Mig can work, but it isn't as good as Mig using Argon.

* Oxy requires investing in acetalyne and oxygen bottles. You can do soldering and brazing with oxy-propane too, making it a little cheaper. Soldering and brazing can actually produce a strong union than welding can - not hearsay, but from seeing test pieces being loaded using all three oxy joins.

* Regardless of the type of welding you do, you do need to understand the various energy requirements of the thickness of the materials you are going to weld, otherwise you won't get the depth of weld if it is thick, or you may just blast a hole in the job if you go too hard on a thin material.

* All four types have different way of being handled too. Some you push away from you as you weld, others you pull towards you. Some require both hands to be used, one on the welder and the other holding the filler wire.

I would suggest you do a short welding course. You'll learn how each method works, how to do it safely, and what works best and where, and then you'll be able to make the best choice for yourself. I did such a course through TAFE some four years ago - best thing I could have done too. The course won't make you a qualified welder ready to get a job, but it will give the lay man the necessary understanding to not blow themselves up.

Mental.

[2stroke]

Sticks aka arc is the best way to go if its only small jobs, those cheap mig welders are junk from many people i know and have read about who have bought them. I love mig, though the price is to rich for small jobs to justifie buying one the welds are sweet and slag free. Mig welding takes a bit to get use to because of the feed speed and juice rate, then the art of welding on top of that.

Anyhow simple answer is grab a stick if your only doing a few small jobs around the house, just get the biggest you can get if your welding heavy plate. As for tafe courses, do a short if you have the time but if not theres tons on youtube and the internet. Lol i've had my share of weld flash but its not that dangerous, just use common sense, long sleeves, jeans and a pair of boots with jeans covering as you don't want hot foot haha. Just practice with some scrap of the same material you plan to use to get the amps rights and the weld good. If i could oxy fusion, mig and arc back in yr 8 after bugger all teaching i'am sure you can at your age, its not the complicated though getting the feel and a good weld takes experience.

[marki]

MIG is the most versatile and is the easiest to use especially on gas and is the welder I use for most jobs. They also allow you to weld thin metal which I would not attempt with a stick welder. MIG's are restricted when the metal gets thick and if you want to weld anything thicker than 1/2 inch you will be looking at big bucks and probably 3 phase. I have a Lincoln 180C which is a magic little welder that will weld from about 0.5 mm steel using 0.6 wire through to about 6mm steel on 0.9 wire on the gas. It will weld up to 12mm plate in several passes using 1.2 mm gasless flux core wire which I actually did today. In standard form it is good for most types of metals with the exception of aluminium. To weld ali you need to buy a spool gun torch with costs almost 1/2 the price of the welder itself and not all MIG,s have this option especially the cheap ones (more trouble then they are worth usually). You can use gasless wire (flux core) on a MIG so it works much like a stick welder but you get much nicer welds on gas. The problem here is if you go gasless the wire is very expensive and you have to clean up flux and splatter but you can weld thicker metal. If you go with gas the wire is cheap and the gas is expensive (refill costs + monthly rent) but there is no clean up but you are restricted to thinner metal. I normally use argosheild gas for most things and pure argon gas for stainless and ali. You really need to use both gasless and gas wire to have full versatility with a MIG.

Stick welders come into their own if you are welding heavier metals, say 3mm upwards. They are more difficult to use then a MIG as some skill is required to lay down a good weld bead. You also have the problem of removing flux and splatter from your work which gets quite tedious after a while. On the up side they are simple machines requiring very little maintenance and the welding rods are reasonably cheap.

TIG welders are also very versatile in that you can weld pretty much anything but must use pure argon gas all the time or the weld will be rubbish and you will be burning electrodes at a prodigious rate (electrodes are expensive and the thorium type have radioactive isotopes present). Like the MIG they are great for thin metal but stick is a better option for the thick stuff. I also have a Boss 200A TIG inverter which means it can also be used for stick welding so it's two machines in one. If you use it as a stick welder then no gas is required and you just need to set the amps correctly. If you use it as a TIG then better get practising as TIG welding is IMO is the most difficult to master and requires great skill to produce a decent weld. It is also very slow compared to the other types and depending on what level of machine you buy, the most complex to set up. For my MIG it is just current and wire speed, for stick it is just current, for TIG there are more buttons and knobs then the space shuttle.

A word of caution, don't buy a MIG or stick welder from Bunning's, those Ortiz or what ever they are called are rubbish and I don't know anyone who is happy with one. A good quality welder will last for years and it is best to go to a reputable store and buy one even if you get stick welder and be prepared to pay a premium price, it's worth it in the long run.

Mark

[acropolite]

I currently own a Mig welder and have in the past owned a stick welder.

MIG wins hands down IMO, the biggest downside of the MIG is the gas bottle rental cost, which can be overcome by using the small disposble bottles available from mist welding suppliers.

Disposable Gas mix bottles are expensive for the quantity of gas being used but cheap if you're like me and only use the welder occasionally, simply rent a full sized bottle when you have a large amount of work to do and return as soon as you're finished.

As a guide, the rental cost on a large bottle is around $17 per month, highway robbery IMO, price fixing is the norm, so you won't get a cheaper deal.

Gas suppliers get away with such rates because of regulations, (set when gas supply was in monopoly hands) which prevent you from owning bottles (supposedly the need for regular testing and maintenance). Mark mentioned Argoshield, some metals are better welded with gas mixes, usually a mix of Argon and CO2 is used for mild steel.

[toc]

Thanks for the awesome info guys - I think for the small odd jobs I might be doing (i.e welding a steel pier, fixing a gate) the Stick welder might be better for me.

I might just do a short course, but to get me started Ive found this guy was pretty informative.

http://www.youtube.com/user/ChuckE2009?feature=watch

[sheeny]

I've had a little AC welder for years and a couple of years ago bought an inverter welder - 180A 100% duty cycle for just over $200.:thumbsup: Seriously look at an inverter DC welder rather than AC. You get a bit more flexibility (+ve/-ve polarity) and its easier to use.

One of the contractors at work was telling me he bought a little gasless MIG for just over $300... I was kicking myself for not getting one of these till he mentioned that they are fine while your are using them all the time, but as soon as the nozzle oxidizes, the wire feed is very troublesome. So it looks like its better for the constant use a contractor may have than the hobbyist.

For those who have gas MIG/TIG setups, there is now an alternative to bottle hire. I'm told there is a supplier in Katoomba, I think, who you can buy bottles of inert gases from (i.e. you can't buy oxy or acetylene, but you can buy argon and nitrogen, etc). There may be others in your local area;). For me the cost of bottle rental has kept me away from MIG, TIG and oxy... I just don't do enough of it to warrant the cost, but buying a bottle at least you know what your costs are up front. I don't know any more about it, but if its like an LPG bottle exchange, then I think it would have to be a winner.

Al.

[acropolite]

I believe it's the other way round, it's the wire that oxidises (rusts) and the rust then clogs the nozzles. Some wire is copper coated to prevent rust forming. I've had the same roll in my welder for over 6 years without issues.

[astronobob]

Ok, plenty of info there !
I might add, that any welding is an art in itself, some pick it up straight away and others can never get it ? It very wise to have someone else who can weld looking with mask as you weld so they can point pout what needs to be attended to etc, , How strong, how far from the material, how fast/slow to move, it all varies with every job ! things you'll learn as you go !

As for stick welding Peirs, Than thats some moderate thick steel, 10-12 even 15mm, maybe more ,, thick plate. I used 12mm bottom plate to 10mm gussets and an 8mm wall pipe, my 40-140amp welder was struggling to penetrate into 10mm or more, so I had to do some 'fish welds' youll learn about them in due time, but I think its pretty strong, besides, it is only a telescope peir, Not brackets holding a multi story building Lift, : ) Some smaller arc/stick welders only max out at 100ampsand will be struggling to penetrate 7-8mm.
In theory,rule of thumb, but not quoting, a 1 inch weld in 10mm steel properly done should hold a tonne of weight ! !
Once you learn welding, it sure come in handy ! cheers & all the best with it ! !

[asimov]

Won't bother adding a lot here but suffice to say I used to get payed poorly to weld lol..Bob's spot on & I have to laugh at the fish welds mate...You want chips with them or what!?:lol:

Go the arc welder but it's an art form in itself.

[Poita]

Get a good Mig if you think you are going to do a lot of welding, but go do a course first before spending the $$$. The person who runs the course can then recommend you a reliable unit.

[clive milne]

I think the maintenance issues (elaborated above) are somewhat over stated. You can get away with a fair bit of spatter stuck to the nozzle without any problems.(unless it is windy).... The gas comes out at 20L min after all.

The only time you will be faced with repetitive nozzle cleaning duties is if you are welding galvanised steel. If you are welding 'hot dipped steel' you really should grind away the zinc before attempting to weld it.

To basically eliminate spatter sticking to your nozzle, there are a couple of products to consider. Nozzle dip, the synthetic stuff is better than the traditional lanolin. Anti-spatter - the detergent type is much cleaner to use than the oil based stuff in the pressure cans.

To reduce clogging of the tip, feed a foam earplug on to the wire just before it goes through the drive rollers. It basically brushes the wire clean before it goes in the hand piece.

You can run aluminium wire through a normal MIG as long as you are careful. Use an eraser to keep the vee grooves in the rollers clean (regularly). Keep the hose going to the hand piece free of bends and don't weld in dip transfer mode.

Helmets: You can get a reasonable auto-darkening helmet from ebay for 70 bucks.
If you are going to be welding often, a Speedglas should be on your shopping list. The entry level model (100V) is $300. That sounds like a lot of coin, but once you use one, you will never want to go back.
Which ever helmet you choose, just make sure you can easily get replacement clears.

~c

[tempestwizz]

My main use is for Aluminium.
I have built a couple of Dobs so far using aluminium.i tried using a cheaper MIG the first time, and a combination of under power and under-gassing did not allow ideal results. The weld stuck to the surface rather than penetrating the base material. The other issue I found with MIG is that the welding material begins to come out as soon as you pull the trigger, and you have to be ready to handle it.
The outcome has functioned quite OK I must say.

After practising with a friend's TIG, I bought my own, and have had much better results. I would call TIG the 'gentlemans' welder. It is not fast, and probably more expensive to run, but I find the results far superior. The area to be welded is heated with a plasma, then filler rod is applied as and when required. (Unlike MIG which spurts out wire whenever trigger is on)

I am self-taught, and would probably improve with some formal training, but managed the TIG quite OK with a bit of help from the Web.

My vote is for TIG

[astronobob]

Lol, your a funny man Clive ;) Thats quite a list mate, and I for one appreciate you filling in all them gaps, parden the Pun, but sometimes you end up with gaps when your welding :D
But yeah, thanx for backing me up :thumbsup:

Quote Re Asimov : You want chips with them or what!? :lol:
Lol John, Are you implying my welds are full of pitts & chips mate :P

[marki]

You would need to change the torch liner to Teflon if you are not going to use a spool gun and that's a PITA as you have to be so careful not to run the wire if the cable is bent more than about 5 deg. I would not try with the standard liner as knowing my luck the wire would melt right back to the drive wheels.

Mark

[sheeny]

I thought it sounded weird too, Phil, and we discussed it. He was using copper coated wire, and tried new rolls. As new it worked fine, but after leaving it standing for a couple of weeks while he was on leave, he said it gave him trouble. He didn't say how long it took to fix it, or how many times he's experienced it.

It might just be something peculiar to his handpiece too, so not saying its a fault with all gasless MIGs - just something to keep in mind.

Al.

[clive milne]

A couple of points with respect to welding aluminium with a MIG.

You don't absolutely have to use a spool gun or a teflon torch liner, although they will make life easier.

You don't absolutely need a high current welder to weld heavy gauge aluminium. The welder I have at home is only 130 amps, and while it is true that most people will struggle to get a decent weld on anything greater than 3mm plate with it, it is also true that you can get decent penetration and a cosmetically perfect fillet on 1/2" plate using the same welder.

The trick to it is to break the oxide layer first, then preheat the weld site using a propane torch.

Easier still is to just use a TIG. If the dimensional stability of the piece you are welding is critical, TIG is the only game in town (for aluminium).

[Poita]

For Aluminium, I agree wholeheartedly, a TIG makes it realtively painless.

[marki]

To maximise both performance and tool life it is best practice to follow the manufacturers instructions. Welding aluminium without a spool gun or at the very least a Teflon liner could result in expensive damage to the torch and the machine itself. Of course the choice is always yours just don't complain when things go pear shaped.

[clive milne]

I'm curious, specifically what damage do you fear doing to the hand piece or machine?

[DIYman]

Many years ago I bought some flux covered aluminium rods for use on a DC arc welder. They were bloody expensive and although I am an experienced arc welder they were not easy to use. I had to run a grinder over all my welds to make them look anywhere half decent.

I still have the old dob mount around at home on which the welding was done. Its kept hidden at the back of the shed. I shudder every time I stumble across the mount during my annual shed clean outs. When the mount was in use, old experienced club members would look at it (and my welding no doubt ), mutter something under their breath and walk away.

One day the mount will disappear at the bottom of a junk verge collection and that source of embarrassment will be out of my life once and for all.

[marki]

My machine is only 180A max which means I can only use very thin wire for Al, (0.35-0.45"). It is very fragile. My machine has V groove rollers on the main feed which causes the wire to chip and this clogs the liner and small flakes of Al are nearly impossible to move once deposited. The thin wire also buckles and burns back easily adding an even bigger headache and the liner must be replaced far too regularly to make it worth while. Spool gun = short wire feed = no bending or flaking = happy welder.

[wasyoungonce]

I've been trying to teach myself stick..very average so far but getting better. Found I needed smaller electrods. I was trying 2.5mm on a 100 amp cheapie arc. Went to 1.5 & 2mm and much better.

I booked myself into tafe mig/tig course, 28 hrs. Sure...I won't be proficient on that time on training but hey it's a start.

I'll never be a pro but just wanted to learn enough to get by.

[StutzJr]

Great thread, very informative stuff. I'm also interested in doing a tafe welding course eventually.

I have a specific question relating to the welding of fine gauge wire thermocouple junctions. I'd like to know the best option(s) for welding precision grade thermocouple wires ~24 AWG (0.5 mm diameter or less). The idea is to twist a short length at the end of two wires of dissimilar metals and then fuse them together into a small bead. Soldering is not an option due to the introduction of contaminants and the intended temperature range of the t/c. Similarly with silver soldering.
I have found that a butane torch is not hot enough and/or is not able to fuse the wires without oxidation. I have tried capacitor discharge (resistance welding) with carbon terminals but do not have a large enough capacitor to get an effective weld. A workmate has a MAPP gas burner but I expect it will only be a marginal improvement over the butane torch.
I've been advised by a local supplier to try a neutral flame on an oxy welder. I don't have access to any oxy-acetylene gear but I am considering investing in an oxy/MAPP welding kit. I've also been eyeing the aformentioned bunnings special arc welders.. Lastly I have been hearing a lot recently about jewellers using HHO welders (hydrogen-oxy derived from water) but I believe that these units are pretty rare and expensive around here.
Can anyone here suggest what technique/equipment would be the best option for my application?

[wasyoungonce]

IMHO...maybe 3 methods (depends on junction type or wires used):
1. Use an oxy torch to melt the wires together.
2. Spot weld them, maybe pass an inert gas over them when doing so. This way the junction fusing is just a product of the metals used in the wire. I did see someone using a capacitor discharge bank to spot weld small stuff. This may be ideal for this if you use the actual thermocouple wires as the electrodes (aka do not introduce other metals)
3. TIG weld fuse them using no filler, if it doesn't completely ionise the wires! For the same reasons and also noting TIG gasses from the hand-piece will keep the joint from oxidising and introducing contaminants.

IMHO the only real method that will work is spot welding or oxy torch.

The reason no filler is that the thermocouple junction it self is produces a voltage proportional to the metals used...like Chromel/Alumel. Introducing another 3rd element metal will throw the junction way out.

Week 2 of my Tafe welding course...they won't cover stuff like this...just from memory from Jet engine thermocouples.

[StutzJr]

I wouldn't expect to answer this specific application with the tafe course but it's still something I'd be interested in.
From your methods I'd be more likely to choose options 1 or 2. I don't know anyone with TIG gear and I get the impression it would not be a beginner's option.
When I was trying the capacitor discharge method I used a 25V 220000 uF cap. I had the negative lead wrapped around a carbon rod from a C cell battery with the tip ground out into a well and a drop of glycerine inside to minimise oxidation. I held with tc juction just short of the tip with a crocodile clip attached to a decent copper cable. When I contacted the tip with the carbon rod inside the glycerol drop I got a flash spot weld with minimal oxidation but it barely held the wires together. If I had a larger capacitor bank it might work but I've also read it would work better if the junction was held in contact with the carbon rod and the current was switched with a mosfet. That's starting to sound more complicated and I can see the oxy torch having more uses if I can only justify the cost.

[wasyoungonce]

Yep sounds like more current needed to fuse..or putting all that current into a very short pulse hence mosfet switching.

Has me wondering if an old car coil can mosfet switched be made to supply a arc to join them. probably the coil inductance will delay the current too much hence most people go for capacitive discharge spot welding?

[StutzJr]

I think the cap discharge is just the easier option. I haven't looked into the switching/coil option as I haven't had time yet. A quick youtube search for "photonicinduction melt" shows an extreme example... I figure if the switching circuit gets too elaborate then I might as well fork out for an off the shelf arc welder.

Oh and I never know that mexico city was so close to geetroit! lol