I have got a MIG welder, had it for a while, got used to it, as I am planning on building a chassis, wishbones etc.
I have not done that much welding with it, just practising before attempting on doing the chassis - built a workbench...
Was reading a book on building a single seater, and it that it advised that you should only really use a TIG, so you are able to get a weld into the
tight areas, and it put less weld on (so less overall weight).
What are peoples thoughts on the area who have built a chassis/wishbones with a MIG, would they of preferred to have had a TIG, or is using a MIG
nearly just as good? And what is a MIG like in getting the torch into the tight areas? Did you have to just leave it, as you could not possibly weld
these areas?
I know a TIG is more expensive etc, and (or so i have read) harder to master, but just confused - just really want to double check I am going down the
right route, and if not do a U-turn, and in the process learn a new skill.
If people would advise going down the TIG route, then what is an OK TIG on a budget?????? I know I would have to look second hand.
[Edited on 13/2/10 by m8kwr]
Horses for courses
For welding a chassis and wishbones as per the book a mig will be fine.Don't make it any harder than it already is.
If you're using mild steel tubes with a decent wall thickness (i.e. 16g) then a MIG will be fine. TIG welds will look prettier but there's
realistically no benefit as long as the chassis and wishbones are vaguely sensible in their design.
If you're using waffer thin tubing or heat-treated (i.e. CroMoly or T45) tubing then TIG is superior as it will reduce the impact of the welding
on the heat treatment (assuming you're not getting the parts heat treated after welding).
For a standard Locost chassis/wishbones MIG will be fine.
I happily enough have both, and for chassis and wishbone work I use the MIG rig. 'nuff said... 
MIG is a quicker process, and that's why it's used so much in industry.
It's because TIG is slower that it's relatively easy to get the hang of.
More time to watch what the molten pool is doing and more time to make the necessary corrections.
My advice would be to have a go with TIG before you commit to buying one, or not as the case may be.
I've had loads of people have a go with mine. Some take to it like a duck to water.
I'm a bit distant, but there must be someone near you that fits the bill.
An hour or two spent with an experienced bloke will save many hours of frustration trying to master the skills on your own.
HTH
Paul G
I don't think there are many places on a chassis that it's neessary that it will nly fit a TIG head, so if that were the only reason, then MIG your chassis with the welder you have and then get someone to TIG weld the last couple of runs, it will only cost you a few quid if at all...
In my experience (not in locosts but welding in general) the MIG will be the better choice, while TIG will give you a better finish it is a painfully slow process and is also for the most part a two handed process. If you are welding at an odd angle or lying under a car on something being able to do a complete MIG weld with one free hand is a god send.
Are you one of those people who can pat your head while rubbing your stomach?
Tig is a two handed operation.
One guides the torch while the other feeds the rods into the pool plus a foot pedal controls the current.
Some people have difficulty with their feeding technique so have a go first before you buy a TIG set up.
Another reason MIG is more popular is the equipment is a lot cheaper.
Oh and if you buy a TIG, I recommend one with a foot pedal and not a scratch start.
I occasionally spark some bits together with my old mig and it works fine.
I also have had a small go on a friend's 3 phase Cebora AC/DC Tig set. I won't begin to pretend I mastered it,but given an hour in a no
pressure situation, I reckon I could get up to a usefull standard.
The same friend uses the tig for every inch of weld on everything he builds.
Having had the pleasure of watching at close range and seeing the finished job, I know which process I prefer.
There's much less fury about the tig process, it all happens at a relaxed pace and there's none of the sparks and general feeling of
theatre, for want of a better word, that you get with the mig.
When he's doing a tig weld in a tight corner, you can stand on the other side of the 25mm tube being welded and not need to shield your eyes. (I
won't comment on UV protection for skin, that's a whole different discussion.)
It's safe to say that tig is something I will be trying myself soon.
The chassis which my friend has built always draws comment on the quality of the fabrication. If this is is important to you, TIG might be worth
considering. As you might have guessed, I'm a fan.
Ive got both, and MIG is absolutely much easier. TBH IMHO i doubt that the additional metal used by the MIG would add that much more weight than dust
or rain! - Negligible if you ask me unless you want a formula car.
TIG is more suited to intricate pieces and unless youve got a proper workshop, TIG welding proves to be a pain in the arse, as the torch etc are much
more fragile than a MIG and you run the risk of damaging something on it.
Its really very good, but for the future, ill be keeping mine to bench weldable items in a clean environment.
Oh, and youll need a bench grinder to be able to grind the tips properly. Something that not many do, and TBH i only do it on a new tip or if it
bobbles too bad.
quote:
Originally posted by MakeEverything
Ive got both, and MIG is absolutely much easier. TBH IMHO i doubt that the additional metal used by the MIG would add that much more weight than dust or rain! - Negligible if you ask me unless you want a formula car.
TIG is more suited to intricate pieces and unless youve got a proper workshop, TIG welding proves to be a pain in the arse, as the torch etc are much more fragile than a MIG and you run the risk of damaging something on it.
Its really very good, but for the future, ill be keeping mine to bench weldable items in a clean environment.
Oh, and youll need a bench grinder to be able to grind the tips properly. Something that not many do, and TBH i only do it on a new tip or if it bobbles too bad.
quote:
Originally posted by nitram38
Oh and if you buy a TIG, I recommend one with a foot pedal and not a scratch start.
quote:
Originally posted by MakeEverything
Just to add, I used CO2 for the welding, but it does get very hot. Consequently, Ive burnt through more tungstens than i needed to have and everything got just that little bit hotter. Argon is the way forward with TIG, but for DIY purposes, its a nightmare to get hold of.
quote:
Originally posted by Brommers
quote:
Originally posted by MakeEverything
Just to add, I used CO2 for the welding, but it does get very hot. Consequently, Ive burnt through more tungstens than i needed to have and everything got just that little bit hotter. Argon is the way forward with TIG, but for DIY purposes, its a nightmare to get hold of.
I wouldn't say getting hold of Argon is a nightmare. OK, setting up an account with BOC is a bit of a faff but at the end of the day it only requires one phone call and one form to fill in - hardly that onerous. Once you've done that, it's simply a case of popping along to the local BOC stockist when you run out and getting a new bottle.
The rent on my Energas cylinder works out about £1.20 a week over the year. I don't think that's too steep, it would just about buy a half
of bitter round here.
If you do buy a tig don't try to weld anything structural with co2. The tungsten and carbon will be included into the weld, only inert gases
should be used.
I have got a gas bottle from Adam Gas, about 90 ish for the first bottle (includes 40 deposit), then around 50 for each refill.
Not had to have a refill yet, but I think i will very soon, had it for nearly 18 months, no weekly/monthly rental chargers.