Gas Welding or MIG welding.

[superfly]

Hi all,

I am a complete newbie in welding.
I give you a bit of background, I am interested in restoring car.
I have at the moment one car project that needs welding, and I am a bit tired to looking for somebody to help me. So I have decided to stick the finger out and learn it.

I am going to take some welding courses, I have booked 30 hours of welding in a FAS Training center (Official training center in Ireland).
So I believe I should be able to weld after it.

At the start I was thinking about MIG welding but the instrutor explain to me GAS welding maybe more appropriate for my needs (restoring car).

As I gather information here and there I understand GAS welding could be expensive. Some people told me, I should learn in Gas and then do MIG as it will be less expensive, I have no problem doing this but I would love to know more about Gas welding before make a decision.

What do you think?
What budget should I plan for my own gas welder vs mig welder?
Do you have any url or contact for gas welding in Ireland?
I believe I need to put figures around my ideas

Thanks a lot for your help
Superfly

 

[john224]

gas mig

My self i would go for mig welding for car repairs once set up you should learn quicker I/e should be able to stick two bits of steel togeather after first or second lesson PLUS less dammage to the car pannels,,

But thats my thoughts the others on this fourm might have different idears,,,

 

[zzr1200]

Gas can be used to weld steel/alloys plus brazing/soldering/lead filling within reason any thickness material you will find on a car, BUT and its a BIG BIG BUT controlling the distortion in the panels is almost impossible on modern day thickness car panels, .

Also with gas welding gear you have the option of heating seized nuts/parts which is about the only really useful feature of gas equipment today on cars.

My advice would be to save up and buy a decent mig using Ar/Co gas and then if you find you need/require the other flexibilities of gas (Ace/Oxy) add it as a extra later.

Mig rules on car bodywork these days, and buy yourself an auto darkening mask before you do your course, its so much easier to weld with one, and a must have for car welding!!!

hth

zzr

 

[piman]

Hello superfly,

I would disagree with Zzr, oxyz\acetylene welding has many advantages over MIG. He mentions thin steel on modern cars, but most restorations are for older cars? I understand also that modern car bodies shouldn't be gas weldede due to the type of steel now used.

Distortion can be a problem so you do need to be aware of the way to minimise it. Your tutor would be better placed to advise you on technique.

A gas weld is softer so more easily dressed with a hammer and generally you have a smaller, neater weld profile that needs little or no grinding down. You can weld out side as well if you need to. The big bonus is it's versatility.
If you only want to do one car then a MIG would be more economical but if you expect to do a lot of work then go for gas.

Alec

 

[superfly]

Hi guys,

I would like to start by the car I have at the moment it is a porsche 924 from 1982. I don't know if it is a modern car for you?

To be honest I really don't know if I will do a lot of car in my live ! I might doing this one and then none for 3 years than another one. Or else I might do a Mini or a Cox after ;-)
I love old car, after it is really depending on time and space ;-) I love to have a fleet of nice car ;-)

For the Gas welding, I was thinking maybe a small welder (my dad has something similar for plumbing) there is wheel so it is easy to move and probalby sufficent for my needs.

Most of my welding will be done outside as I don't have a garage to work in.

Thanks a lot for the advice for the mask, I remember a couple of year ago try Arc welding with a mask I could not see through it !! Conlusion I was unable to weld ;-)

Do you not think even if I am going to weld using MIG in the future I should learn Gas and transpose what I have learn in MIG?

I have to say I like the idea of GAS because it is versatile.

I believe it will all go down to the price at this end.

Thansk
Superfly

 

[piman]

Hello Superfly,

well 1982 is modern to me, I've never owned an eighties car or newer.

Both our family cars are 1968. However I would be surprised if your car has thinner than 20 gauge which is normal for 60's bodywork, and 18 gauge for chassis members.

Alec

 

[superfly]

So my car is a modern one ;-)

So you believe I should go for MIG all the way ? Or learn Gas and do MIG after ?

Sorry I look a bit slow but I know nothing about the topic ;-) and as you know the gear are pricing so I try to make the right choice to get the maximun of my courses as they are pricing as well.

Cheers

 

[hotrodder]

Early eighties Porsche... probably contains a bit of basic HSLA steel but is before the era of the super high strength stuff and really stupidly thin panels

MIG or oxyfuel...

Welds shrink. As they shrink distortion occurs

Oxy does have many advantages but you need to be a skilled panel beater to get the benfits. As said oxyfuel welds are softer and because the amount of filler used can be minimised welds can be 'planished' smooth- hammer and dolly work on the weld bead stretches it (countering the shrinkage) and flattens the weld. Little to no grinding needed and (with enough skill) no filler necessary

Oxy is also incredibly handy to have around... free off sized things, burn out seized stuff, heat shrink cut etc etc.

MIG welds are relatively hard and physically larger/have more reinforcement. Can't planish out distortion and the welds are less workable with the hammer and dolly. Plus side is that because the heat is far more concentrated less distortion occurs and with the right technique (see the tutorial section) can be almost eliminated. Far more grinding/sanding will be needed and filler will be required (done right still very little though)

If you're at college i'd recommend starting with oxy fuel. If nothing else it'll give a better understanding of welding (controlling a weld pool etc) and you'll almost certainly end up a better welder. The right choice for restoring your car will depend on your skills with a body hammer. Ideally you'd have both as a MIG will shine when replicating spot welds and the workability of oxyfuel welds is of little use if you can't get to the back of the panel

 

[shenion]

Although gas may be easier to smooth out and finish the welds, I don't see it as the best option.

Unless you live where you don't have to rent gas cylinders, gas will be expensive as you have to rent 2 bottles. Add to that the cost of a good gas torch, flashback arresters, hoses etc gets near the cost of a low-end MIG. I think others have said they have not seen any 'rent free" O/A bottles on your side of the pond.

MIG has the same problem but only one bottle. You can use disposables, but they are expensive if you plan on doing more than just a very small amount of welding. Check the "rent free gas" thread. If there is a supplier in your area, that will make MIG less of a cost of it just sitting idle. Another option is to use a pub CO2 bottle. Not as good as argon/CO2 mixes but no rental. You might consider a reg for both types of bottles with the appropriate adapter. Keep the CO2 for general welding and rent the Ar/CO2 for a month when you have a bunch of bodywork to do.

For gas, you might look at an oxy/MAPP setup. I have had two of them (anyone remember the old solid oxygen "bricks"?) They are expensive to run, but reasonable for a single project. They are not hot enough for "real" welding, but can do bodywork. They use disposable bottles, for general heating/brazing, I swap the MAPP can for a standard propane can; was cheaper. I used it for brazing as anything thicker than sheet metal, you could not get it hot enough and ended up getting the entire part hot. They are still available and some new ones around (HTS-1000?)

You will need to look at how much you will use it and how often. If you can do all the work in a short period, then renting the entire setup may be the best option. Or buy the torch, and rent bottles for a month.

I have an O/A setup (Chinese cheapie) and MIG/TIG/Arc welders. The O/A setup, i have never had the acetylene tank filled. I just use propane as I use it for brazing, freeing stuck parts, hardening and blackening things. Real nice to have around, but I don't have any rental on the bottles. It has many uses the electric welders can't do. If I had to rent bottles, I could not afford it.

Either will do the job; the cost vs use will probably be the biggest factor. I'd look at supplier and price up options.

I will warn you, it will cost more than you expect as the "welding bug" will make you want more. My little Clarke MIG made me get TIG/ARC and a big MIG then an O/A setup. The cost of teh CLarke was just a down payment

 

[piman]

Hello Shenion,

yes there is the rental of two bottles, but if my TIG set as an indicator I use a lot more gas with TIG than oxy\acetylene even with two bottles. (I rarely ever use it for cutting)

I agree that it is more expensive to buy and rent bottles but for me it is worth it, but everyone to their own.

Alec

 

[superfly]

I have done already 3 hours of Arc Welding and 3 hours of MIG Welding.
It was really insteresting.

I have made my mind, I will spend about 15 hours in total in MIG Welding, and 12 in GAS.
So i will get a sense of both

Thansk a lot for your advice.

 

[Lewis Medlock]

Get a MIG for goodness sake!

Cheap as chips and you'll get good results straight out of the box and excellent results after 12 hours practice at school, when you decide you want to go further and do other stuff then consider investing an awful lot of money in an Oxyfuel setup.

You'll get a Mig for the price of an Oxyfuel cylinder trolley

Good luck with the welding course superfly and have a load of fun


All the best, Jim

 

[piman]

Hello Jim,

basically you get what you pay for, so a cheap MIG gives limited welding capability.

It entirely depends on how much work you need to do and for how many years.
I have used gas for very many years and would chose that over any other machine if I had to have only one type of welder. In view of the length of time, how long do these cheap machines last? I seem to see quite a few posts about faults with wire feed for instance?
Relative to that, I think I'm on my second acetylene regulator and just a few replacement nozzles in over twenty years use.

Alec
PS I fabricated my own trolley :-)

 

[runnach]

If cost is not an issue and, you have safe premises to store Oxy-Acet (safe as in, not stored to garage attached to house). Oxy-Acetylene is the way I would go for car restoration, as Hotrodder stated, with O&A you get a better eye and feel while welding, heating till weld pool is suffice, then continuing till weld is complete, if to hot, you can flick flame away to control weld pool.

Of course mig has its own benefits, for a newbie, there is very little control while welding thin material, point and squirt hoping not to blow through. There is also the added problem of getting a decent current return if material is rusty, then there is the problem of trying to weld rusty material. No such problem with O&A!

Cheers............

 

[Rusty]

Hi superfly , I had both Gas and Mig but found at the time having to rent three bottles a bit expensive and after considering the positives and negatives of both I went for Mig , I can relax a little now knowing I haven't got a possible ' Acetylene Bomb ' in the garage also I found the Mig safer to use around cars as you don't have that Gas flame burning anything within a couple of feet of the torch With Gas you weld , do a bit of shaping , bit more welding and so on but the gas torch is on most of the time which is wasteful whereas with Mig it's only working when you pull the trigger.
Also generally you need 2 hands with Gas but only 1 with Mig ( providing you use a head shield ) and it is so handy to be able to position panels with one hand and tack with the other , the Mig is much more ' user friendly ' but I do miss the versatility of having Gas around .

 

[Lewis Medlock]

Hi Alec,

Your points are all valid, I completely agree.

My reasoning is that someone completely new to welding will achieve better results faster with a MIG set. Good gas welding takes a lot of practice.

Incidentally did you know that you're supposed to bin oxyfuel regulators after 5 years now! I tried having a pair serviced recently and BOC wouldn't touch them. It took me ages to find a replacement gauge for one.

All the best, Jim

 

[piman]

Hello Jim,

that's news to me, my acetylene is virtually new so I'll need to get a new oxygen one then?

Alec

 

[Lewis Medlock]

Hello Jim,

that's news to me, my acetylene is virtually new so I'll need to get a new oxygen one then?

Alec

If you ask the people who make regulators it would seem so, personally I'm sticking with the ones I've got as decent two stage regs are about £120 each, that's a lot of cash every five years

Here's a thingy about it, the bottom of the page is the 'five year rule'

http://www.proactivegassafety.com/content/regulator_fitting


Mine are of an unknown vintage and I haven't blown myself up yet, when I do I'll be sure to buy new ones. I do have decent flashback arrestors though and I can run like a stabbed cat.

All the best, Jim

 

[Jocky]

If your doing all your welding outside its got to be oxy/act.
Years ago when I left school I did an engineering course and used all types of welding throughout the course and I found gas the easiest on car bodies, maybe its just me!!!!!!!
I've still got gas gear but no bottles and I went to rent some and the price is unreal I've also got a decent mig which gets used on cars, but I miss the flexibilty of the gas for shaping etc, even heating underseal to get it off

 

[the snooper]

oxy/act is slow when compared to mig and will put more heat into the work piece, if you intend to work outside make your self some wind breaks and you will be fine.
but as pointed out oxy/act is good for shaping and alike