MIG Welding alloy?

[minivin]

Ahkay, know very little about welding, done a little brazing many years ago while at school and give me a soldering iron any day as that's my trade. However a few too many times I've gone to people to get welding done and then been let down, so thinking of trying to teach myself

Pretty much the only stuff I want to do is no thicker than 3/16 Mild Steel and I would like the capability to do light aluminium work as well.

I have been looking on Ebay and reels from Sealey et cetera are available for doing alloy welding, but that's all I know.

Do these reels need an alternative gas bottle? is more, same or less current needed?

I don't really want to be spending hundreds of pounds on kit, firstly because I don't know whether I'll be any good at it and secondly I don't have a garage so all welding is done outdoors.

Any comments greatfully received as I suspect I've left it very broad

[LandyManLuke]

Welding outside as such isn't a problem, you just need to make some screens up if it's a breezy day ( yeah, picking a windy day is a bad idea) and compensate by turning the gas up.

I reckon you'd get through those crappy disposable bottles really quickly outside.

my 2p

Luke

[Astro_Al]

Ok, I'll start the ball rolling, then someone who knows what they are talking about can come along and give some useful input...

First off, it's tricky welding ali. Harder than steel. There are several issues here. The first is thermodynamics. Ali (or it's alloys, cos you'll never be truly welding pure ali) has a very high thermal conductivity but a low melting point. This results in a crappy combination of needing a fair bit of heat because it's all being leached away into the rest of the material so fast, and needing very little heat because it melts so easily and you'll be blowing holes in it the whole damn time. The balance requires skill, sadly...

The second pleasantry is that alumium forms an oxide in air. If it's not Uber-Clean when you weld it, these oxides will be present in the weld pool (as solids!). You don't want particulate carp in your weld pool, this is bad. The problem is that this carp doesn't melt, or rather it does, but at a MUCH higher temperature than the ali which you are welding, in fact, ali oxides have melting points above the BOILING point of ali! In real terms, this means that you'll never get them hot enough to melt when welding the ali, so they must be removed mechanically first instead.

Use a stainless wire brush which is NOT used for anything else to clean it up gooooood just before you weld.

The next issue is the damn wire wanting to get stuck on its way from the reel to your torch. You need a nice new teflon liner for it to feed down, preferably not one you've used for steel. To help things along, use a cable from welder to torch which is quite short, so you reduce the overall resistance to the wire's movement. You can also experiment with using a tip one size too big for the wire - i.e. if you have 0.6mm wire, use a 0.8mm tip etc etc. This may just complicate things to start off with though. When learning, don't fiddle with too many variables at once, you'll never get to understand what does what.

People often say that using new rollers for the wire feed is a good idea - you want to keep them blemish free where possible, so they don't nick the wire and encourage it to stick in the tube to the torch. Keep them separate from your steel feed rollers. Steel wire is obviously more resilient to this. You'll also have to alter the tension of the rollers accordingly.

I'm a bit confused cos you say you don't weld, and then that all your welding is done outdoors...? Anyway, IMHO if you want decent results without using flux cored wire (you do), then perhaps you could rig up some kind of shelter to keep the wind off? I've welded outdoors - it's do-able, but not ideal. The gas will blow away. Increase the feed rate (gas) a bit to compensate, try different nozzles too.

Absolutely definitely start on steel. Reasonably thick - 2/3mm is good. Play with stuff/settings. Test your welds - try to destroy them, look at the penetration on the back side, cut them through the cross section and see if you are just painting wire onto the outside or really fusing metal together through the thickness of the piece. Remember - your soldering and brazing uses different principles to welding. Try different weld types - butt, lap, double-loop-triple-salco etc etc.

When you can do all that, try working with thinner steel - try using pulsed welding with more off-time to allow heat dissipation, again explore all the variables - wire feed / gas feed / distance from the torch / angles / feed direction etc etc.

When that's going good, try some ali. You'll almost certainly need to use a pulsed weld with significant off-times (like a second or so) if it's at all thin stuff to allow it to cool locally, maybe use a heat sink of brass or copper to rest the work on, think of it almost as a series of spot welds. I think the trick is getting good penetration from each pulse without burning through.

carp - didn't mean to write all that, sorry. Hope some of it is useful. Welding is FUN! Don't let this list of 'issues' put you off, but it will take a while before you're getting good results on ali. By the way, I can't weld ali.

Considered tig?

The above could very possibly be complete drivel. Cheers, Al.

P.S. There are some decent welders here, I'm sure one of them will be along in a minute... B)

[dollythelw]

if you want a cheap and easy mig solution to Ali - buy a Ready Welder, essentially a battery powered spool gun, you can run them gas or gasless, the usual ali hygiene rules apply, builders tarps from B&Q make good weld shelters for £7 (but dont torch yourself )

Mig is one thing Tig is a whole other ballpark

[Hybrid_From_Hell]

K my 2p worth

If you can do a short course at a tech college at night, you will learn a lot very fast

Welding is not welding, so decide what you wnat to do, MIG is fairly easy if you have the basics and a decent machine, ARc is er well gone out really with the Arc too unless you really need it, also known as MMA

Gas is an art form, Gas welding needs serious knowledge practise and is a real skill, as is TIG (ali) welding and for ali you'll need pure argon

If you buy a MIG welder do NOT but some cheap C**P, buy the best you can afford so as to get the real benifits, better to run a quality MIG set at 30% of max than some POS MIG flat out - thw eld qulaity will be worse and you'll be waiting for the duty cycle to come back on line as the machine will trip out and switch off due to overheating

Get a BOC account, use agrosheild, not CO2 nor silly disposable bottles......cheaper and AS is better than CO2 for weld qulaity

Buy decent gloves and a autodarkening headset

Learn how to weld steel OK before you try anything else, else you'll be skilled in nothing and confused.

Ali Spool on Gun are ok, but no real replacement IMHO for proper TIGing.

In really simple terms if when you are welding the noise coming to your ears sounds like bacon frying then your close....

Lastly, clean everything steel, ali etc, people often think that "new" Balck metal is ok, sort of, clean it with a flap wheel and your welds will be better.......and equally clean off wherever you place your earth clamp - same reason

HTH

Nige

[gn3dr]

This is what you want - (I'm the seller)

I previously tried the aluminium wire on a MIG and it was a waste of time and money whereas I was able to get good weld on one of these after a few hours practice.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...E%3AIT&rd=1

[Ex Member]

As another opinion, MIG is horribly difficult to get a proper structural weld. People use it because it IS easy to get a good looking weld. However, getting a weld that will pass destructive testing is quite hard, requires a lot of testing and skill.

I work in an industry that builds basically everything with welds. We have full time inspectors and spent a lot on weld testing. On the last major project I worked on the head welding inspector would not let a MIG machine on the site. TIG or stick only. Aluminium should be welded with TIG.

It always scares me when I see all of these people welding structural components on their vehicles with MIG.

[dollythelw]

we used to manage rolling stock, tank components, submarine components, pressure vessels, ROV's etc with MIG (albeit all X-rayed) but as a process it seems to stick stuff ok, each tool has its use, its taken time but the lab has enough welding hardware to weld up a small army, TIG MIG ARC and Gas.

if its anything you need to rely on then go to school/college and be taught - 3 years well spent IMO

[Turbocharger]

Mature, sensible contribution to the forum:

agrosheild

snigger

[/mscttf]

I'd agree with the recurring advice here - go to college. If you play your cards right, buy a MIG for stitching your own scrap sculptures at home, and use the college machine for your ali welds.

[Astro_Al]

This isn't what you want - (I'm just pimping my carp)

Fixed it for you. Are you trying to help, or just sell your stuff?

Ignore him Minivin, that is not what you want. He is right though that you'd need AC if you were using Tig.

As they have said, ideally you'd tig ali, but break yourself in gently. If I were you, I'd be looking for a second hand Mig - all the usual makes that have been suggested here before. Approach it from that angle.

A decent tig machine is a very tricky way to start IMHO.

As Red90 said, be wary - don't assume because it looks good it is; but of course practice and testing of your weld's integrity will yield results.

See here for advice too: http://forums.lr4x4.com/index.php?showtopic=448

Al.

[Ex Member]

we used to manage rolling stock, tank components, submarine components, pressure vessels, ROV's etc with MIG (albeit all X-rayed) but as a process it seems to stick stuff ok, each tool has its use, its taken time but the lab has enough welding hardware to weld up a small army, TIG MIG ARC and Gas.

if its anything you need to rely on then go to school/college and be taught - 3 years well spent IMO

Yes, everything thing we do is 100% NDT. All weld procedures are destructively tested. The point was we found to qualify a MIG weld and MIG welding technicians was extremely difficult. Getting the weld as strong as the parent metal took VERY specific and stringent procedures and very good technicians. Your average Joe Blow in his home shop has no chance. The problem is it is very easy to run the arc in the pool and NOT melt the parent metal. It is much harder to ensure the arc is seeing all of the parent metal.

With Stick and TIG, you have much more leeway. Generally if it looks poor, it is poor. With MIG, it can look great and be complete carp.

Any "shop" based vessel (anything not "pipe") is preferably done SAW. It is must faster, easier and the weld quality is unmatched. All small pipe is TIG. All large pipe is TIG root and hot and stick fill.

[Mo Murphy]

Don't bother wasting your gas by turning up the flow if it's windy - it'll either still get blown away or the extra flow will create turbulence which will let air to the weld anyway. Make a good windsheild, leave it for another day or learn how to weld using manual arc (stick welding, hours of entertainment learning, guaranteed )

Mo

[gn3dr]

Fixed it for you. Are you trying to help, or just sell your stuff?

Ignore him Minivin, that is not what you want. He is right though that you'd need AC if you were using Tig.

I was offering help - as you have said I was right about using AC Tig - so . If he takes your advice and tries to buy a MIG to weld alloy then he will be sorry - unless of course he buys one of the all singing dancing pulse MIGs.

I did declare that I was the seller so there was nothing being hidden.

Have you used the welder that I posted the link to?

[MogLite]

Don't bother wasting your gas by turning up the flow if it's windy - it'll either still get blown away or the extra flow will create turbulence which will let air to the weld anyway. Make a good windsheild, leave it for another day or learn how to weld using manual arc (stick welding, hours of entertainment learning, guaranteed )

Mo

Following the advice of some of the pro welders on Pirate 4x4, was to use flux cored wire outside. They were happy using it on serious structural stuff, and its not to be considered a DIY bodge.

Hope it helps

[dollythelw]

...took VERY specific and stringent procedures and very good technicians. Your average Joe Blow in his home shop has no chance.

..........With Stick and TIG, you have much more leeway. Generally if it looks poor, it is poor. With MIG, it can look great and be complete carp.

agreed on the first point however your average home welder isnt welding materials or components that require such a high standard - if welds to that high a standard were required then Landrover chassis for one would fail miserably - porosity and inclusion abounds, material quality is low to medium - its not formula one, more formula haybale

I'd suggest its as easy to form an included or porus weld with stick as it is with any other process, TWI is a good place to refer to.

[minivin]

some very interesting opinions from different angles, I got onto the Salisbury College website last night and found out how bad it had got since I left there a year ago, no welding courses or electrical engineering that I did, however you can do a course on coloured window glass murials

got a stick welder at the moment and I just can't get a decent weld with it, makes Will's welding look quite good (Will, process my membership!!! ), got a whole load of steel offcuts to play with so think I'll get a MIG and have a play with steel and see what happens. Any recommendations or "keep-clears" on brands and what best for about £150?

[Tonk]

Any recommendations or "keep-clears" on brands and what best for about £150?

keep your eyes open on ebay, for that sort of money u can get a decent 170/180 amp s/hand machine, dont bother with mickey mouse bottles, they run out too quick.

if u need some lessons i'll take u over the basics.

[dollythelw]

I think stained glass might be handy - I quite like the idea of an cherubic image, possibly medici influenced for a quarter light - weldings overated, artisan offroad pimping is the way forward

buy something solid, I wouldnt buy a new unit because £150 on a new welder is only going to buy you a silicone sealant gun, if you find one and its localish theres plenty of people that you can ask to come and have a look at it before you commit your hard earned, even U/S quality welders are worth considering as its not often they can be fixed for reasonable pennies, even Fridge now has his own weldamatron and seems to be learning picking up Welder Fu at a good pace

[minivin]

keep your eyes open on ebay, for that sort of money u can get a decent 170/180 amp s/hand machine, dont bother with mickey mouse bottles, they run out too quick.

if u need some lessons i'll take u over the basics.

Funnily enough I been doing a search on stuff local

Ooh, if it comes about I'll give you a shout

[minivin]

I think stained glass might be handy - I quite like the idea of an cherubic image, possibly medici influenced for a quarter light - weldings overated, artisan offroad pimping is the way forward

buy something solid, I wouldnt buy a new unit because £150 on a new welder is only going to buy you a silicone sealant gun, if you find one and its localish theres plenty of people that you can ask to come and have a look at it before you commit your hard earned, even U/S quality welders are worth considering as its not often they can be fixed for reasonable pennies, even Fridge now has his own weldamatron and seems to be learning picking up Welder Fu at a good pace

Oh I can see it now in the back window, the Lord Series 1, looking down onto his Defender, Disco and Rangie minions through the clouds, shinning his Lucas 35W BPF light down onto them

Shall have another looksie on Ebay

[02GF74]

MIG welding ali not easy. I did manage to stick to gether a crack in my tailgate but managedto blow holes in the thin sheet that I later filled in.

I had a go at doing thin sheet - optimistic I know - and it turned out ****e - if there is enough demend, I'll get a picture up of what you can expect.

Usual problems of the wire jamming ofcourse.

For small items, consider using lumiweld.

re: MIG wleding steel, hmmmmm .... there have been countless kit car chassises (sp?) made using this method, very very few have fallen parts.

[HoSS]

This was a useful reference for me - http://www.mig-welding.co.uk/

[Astro_Al]

I was offering help

Suggesting a 1000 quid on a brand new Tig machine thats located in a different country is your best possible advice for an absolute beginner who wants to try welding?

It's as if you have an interest in seeing it sell... - Oh, hang on a minute...!

Al.

[minivin]

This was a useful reference for me - http://www.mig-welding.co.uk/

Cheers, will have a good read of that later!

[Jon White]

I'd second what people say. Get a 2nd hand profesional type machine froma reputable manufacturer. The hobby type ones are rubbish.

I used to have a SIP 150 turbo hobby type machine but now have a 180amp cebora profesional machine. The difference in weld quality and ease of use is unbeleivable!

The other nice thing with the professional type machines is they have a higher duty cycle. The old 150 would weld about 6" of 6mm steel on full power and then overheat and have to be left to cool for half an hour. Veyr frustrating when you want to get a job done!

Finally on the gas point of view get a BOC account and get argosheild.

Jon