The welder selection decisions?

[erikmannie]

To me, Oxy-acetylene is a PITA. Sure, it prepares you for TIG welding maybe, but in my opinion, just buy a TIG then. For what it is worth, I have never seen anyone Oxy Acetylene aluminum together.

If the OP has any aluminum in his near future then he is advised to start with a TIG welder!

 

[FOMOGO]

I learned to weld alum with OA in 1970. To achieve fusion with any metal, all that is required is enough heat, and the proper clean and flux, and if thick enough, some preheat. Pick your poison, many ways to get the job done, and they all have their own up and down sides. Mike

 

[Larry$]

My Primeweld is an AC & DC TIG (and stick) machine. 225 amps. Works like a dream. The operator is questionable though.
The flash was not really a flash in the truest sense of the word. The hood was still down, but I was pulse welding under bright'ish lights so as the arc subsided between pulses the helmet didn't think there was a need to be dark. After much investigation on Welding Web and Welding Tip and Tricks I learned that low amperage TIG is a challenge because the arc isn't always sufficiently bright to trigger the autodark.

In addition to my TIG machine I also have an older 110v Millermatic 130 MIG machine that I use with argon/co2. It works really well.

I've got one of those Little Millers also, seems to work better than it's operator. The limitation is how thick it can weld in a single pass. Sheet metal dust hoods 16 gage is my most common use. Works fine on thin, 1/8"+-. rectangular steel tubing.

 

[graham-xrf]

If the OP has any aluminum in his near future then he is advised to start with a TIG welder!

Aluminum does not glow progressively with temperature like steel. It has a very high conductivity, and sinks away the heat very fast. Easier if the entire piece can be hot, but otherwise, it is hard to make enough temperature gradient to melt the pool with a flame. When the weld becomes possible, it is near the point where the whole lot will suddenly melt, and it is hard to judge the glow when that will happen. That said, I know a skilled oxy-acetylene welder can make beautiful welds in aluminium.

I think a TIG makes it's hot arc in a smaller region than a flame, but I haven't seen a TIG weld operation yet.

Thanks for your detail and links about polarity selection, DCEN, etc. I recall that at some stage in this thread, it was mentioned that TIG was AC, and clearly there are some weld operations that require that. I never knew that 2/3 of the heat happens on the positive surface where the electrons land, and that polarity is reversed for operations that "clean" the surface, nor that some metals need it that way. That last one having to use special thicker tungstens and water cooling.

It also means that when considering TIG, the option to select DC polarity, or AC mode is a feature to check for when selecting a welder.

In reading about this, I am discovering there are deeper tricks..
The AC frequency can be something other than 50/60Hz, such as we get from a transformer.
The current can be pulsed, with a variable duty cycle.
The current can be servo loop controlled, millisecond by millisecond, as the weld pool varies.

I expect the welders we get are probably simpler things, but advanced electronics in welders is happening.

 

[Liljoebrshooter]

And the answer to any of these questions is how much do you want to spend? You cannot compare a $200 Harbor freight TIG buzz box to a $5000 Miller Prodigy.
Joe

 

[Lo-Fi]

Checklist for a TIG machine:

AC mode: The cheap ones, and pretty much all the multi process machines, are DC only. This is fine for everything except ali. The only control you have to have is AC balance. Frequency, pulse and suchlike are nice to have but not essential.

HF start: this is for arc initiation. Lift or scratch start mean actually contacting the tungsten with the work and lifting it away to start the arc. The opposite of what you want to learn and pretty ugly.

Foot pedal option: personally, I hate using a TIG torch with a button. The ergonomics don't make sense. Even using the pedal as an on/off switch is better than a button, and you can progress to using it for amperage control.

Personally, I respectfully don't agree with advice to gas weld first. It's a vile process by comparison to arc setups, and much as you can vaguely learn puddle control with it, it doesn't really bear any relation to modern arc process skills. TIG if you count having to manually rod feed. It's also expensive for a poor process if you've not got oxy kit already. You might as well TIG right off the bat and skip it if.

A decent gas MIG will have you making passable welds in an afternoon with the aid of some YouTube research beforehand. For gluing stuff together in a hobby shop, it's absolute king. Turn on and pull the trigger.

TIG is a lot more to master... much more practice required just to get the coordination down, much more finicky setup, more gas and endless frustration regrinding tungstens you've dipped accidentally. Also painfully slow, requires absolute cleanliness, total concentration and a post yoga calm. You're pretty much tied to a bench and positional work is way beyond reach without a serious amount of torch time. That all being said, it's lovely, neat, quiet and very flexible. TIG brazing is a great process btw; I'm a big fan.

 

[graham-xrf]

And the answer to any of these questions is how much do you want to spend? You cannot compare a $200 Harbor freight TIG buzz box to a $5000 Miller Prodigy.
Joe

Exactly that was the basis of my question 11.
One answer I got was to avoid the bottom 35%.
I did not express a preference so that the thread could include all welders at any price, for the folk who might read it.

I do get it that there are some spectacular expensive welders, though nearly all do stuff inappropriate for hobby machining. There are some computer controlled things used in industry that can run to hundreds of thousands.

In all the welders I have seen in advertisements, one Hyundai "do everything" type I mentioned before was beyond £800. My thanks for expanding this perspective to $5000 region for the Miller Prodigy.

That one is definitely beyond what I would spend. My judgement does not have the price as the starting point. It begins with "what type of welding do I want to be doing, and what types are there to be doing it with". Then it leads on to usage frequency, and features, and starting to get an idea of other costs - the helmet, the gas, the safety gear, etc.

While taking in these options, I also get a feel for the price. I would likely not be going for a $200, or even $300 "bargain".
HF being USA based, we in UK would not likely import from them, but we have our fair share of low-priced & lower quality outlets.

The "look no further" suggestion from @Lo-Fi for the R-Tech was £415 + VAT = £498, or $662. That would be a significant amount for me, but I am considering it. Mostly, I am just letting the information roll in. It has, so far, included loads of rock solid explanations about most aspects of welding.

--> R-Tech's MIG 180

 

[Aaron_W]

Exactly that was the basis of my question 11.
One answer I got was to avoid the bottom 35%.
I did not express a preference so that the thread could include all welders at any price, for the folk who might read it.

I do get it that there are some spectacular expensive welders, though nearly all do stuff inappropriate for hobby machining. There are some computer controlled things used in industry that can run to hundreds of thousands.

In all the welders I have seen in advertisements, one Hyundai "do everything" type I mentioned before was beyond £800. My thanks for expanding this perspective to $5000 region for the Miller Prodigy.

That one is definitely beyond what I would spend. My judgement does not have the price as the starting point. It begins with "what type of welding do I want to be doing, and what types are there to be doing it with". Then it leads on to usage frequency, and features, and starting to get an idea of other costs - the helmet, the gas, the safety gear, etc.

While taking in these options, I also get a feel for the price. I would likely not be going for a $200, or even $300 "bargain".
HF being USA based, we in UK would not likely import from them, but we have our fair share of low-priced & lower quality outlets.

The "look no further" suggestion from @Lo-Fi for the R-Tech was £415 + VAT = £498, or £662. That would be a significant amount for me, but I am considering it. Mostly, I am just letting the information roll in. It has, so far, included loads of rock solid explanations about most aspects of welding.

--> R-Tech's MIG 180

I have never even heard of that brand, but the specs are quite good. 498 pounds (don't know how to do the symbol) = $662 which puts it at a little less expensive than a Hobart 190 or Lincoln 180 which would be likely candidates for a decent under $1000 240v MIG welder over here. 60% duty cycle at 150 amps is very good for a machine in this class, the Lincoln and Hobart welders are 30% @ 130 A. That would actually compare well to my Miller 220 which is a heavier (220A), and much more expensive machine.
Duty cycle is basically how much of a 10 minute period can you weld continuously, so 30% is 3 minutes out of 10 minutes. This may not sound like a lot, but this is actual welding time, and actively welding for 3 minutes straight would be rare in most home shops. At 60% you will probably never hit the duty cycle of that machine.

I see it has the separate knobs for wire feed and power, but only noted with a scale of 1-10. Personally I prefer actual wire feed (inches / minute) and voltage but this seems to be common on machines at this price point and big picture "better" is probably just what one is used to using.

 

[ahazi]

Addertooth...

It is my understanding that you can run flux core wire in any MIG welder, even if the MIG welder can run gas. Just turn the gas off. Am I wrong? Seems to me I remember doing that at one point (I don't own a MIG welder, just a Lincoln 200 TIG), but I have run MIG a number of times.

Stick welding.... Stick welding is actually rather difficult to do it correctly. Also Graham, stick welding is VERY messy. It develops a lot of splatter and a LOT of smoke due to the flux being on the outside and "burning" off. I only stick weld outside.

Welcome to the deep rabbit hole of welding. A whole 'nother hobby...

Yes, can be done. BUT... don't forget to REVERSE THE POLARITY when you are not using shield gas.

Ariel

 

[Aaron_W]

Personally, I respectfully don't agree with advice to gas weld first. It's a vile process by comparison to arc setups, and much as you can vaguely learn puddle control with it, it doesn't really bear any relation to modern arc process skills. TIG if you count having to manually rod feed. It's also expensive for a poor process if you've not got oxy kit already. You might as well TIG right off the bat and skip it if.

I will agree with those suggesting oxy/fuel as a very versatile process, welding, brazing, cutting, heating material etc. In an educational system it is a useful first step. It is also skill intensive, messy, requires bulky tanks, and a dedicated fire safe space to use it in. Any welder can start fires, but oxy/fuel is several steps further down the path of fire hazard than any arc welding process, only stick and plasma coming anywhere close. I don't think it is really appropriate in the average garage shop, except for the most dedicated.

While I would have oxy / fuel in my shop if I thought I wouldn't burn the house down (I would), I have to accept, open flame has to remain limited. I'd love to have a forge as well (still contemplating how to make that happen without the aforementioned standing over the smoking rubble of my home).