DIY Welding is the topic of many questions on the Forums, and one I answer by advising a LOT of caution, it is NOT an easy skill to acquire, and a welder in untrained hands is a catastrophe waiting to happen!
As an engineer, I have been professionally trained in welding, and remembering back to our lab sessions, I think it was about three sessions before were let any where near a welding booth! The first couple of sessions were all 'theory' about joint types, metal similarity, rod angles and 'puddle forms', which we had to be conversant with before we began. Third session, however was on 'Welding Safety', and our tutor APOLOGISED, that as we only had a twelve day course, he could only give us the 'BASIC' welding safety training!
So I am going to apologise, that in a small part of a small article on the topic, I just cannot possibly give you the sort of instruction necessary to make you a safe competent welder. Best I can do, is give you some advice about the subject, and point you in the best direction for you to do it for yourself.
And the VITAL bit of advice and direction, I would REALLY like you to consider is IF you are thinking about getting your own welding set and tackling your own fabrication work, before you do ANYTHING, check round your local colleges of Further Education and find out if any of them run welding courses. DON'T rush out and buy or borrow a welding set, and start trying to figure out how to use it on your own.
Back to that tutor, so many years ago, the chap more often ran week long courses in industrial safety for companies to send people on to get their H&S certificates, which should serve as a caution. Before any-one in a factory, workshop, building site or other 'place or work' may legally light a gas-axe or plug in a MIG, they have to complete such a course and be 'certified' in their competence of 'SAFE' operation. Note that's the 'Safety Certificate'. Whether they can actually stick two bits of metal together with the thing is an entirely separate matter!
But, any noggin off the street can walk in to Halfords or Machine Mart and buy this sort of hardware off the shelf like it was a food mixer, take it home and wreak whatever havoc they might with it, with little more caution than the 'safety advice' contained in the operating instructions IF any-one bothers to read them!
Take HEED, I have a BIG problem with that. People are a little more wary of Gas welding sets, because they have a very obvious flame on the end of the nozzle, and the gas bottles obviously contain stuff that 's explosive. Arc welders, and, well, ANYTHING that has a three pin plug on the end of it, most people treat with far less concern, though older 'Stick-Welders' some are a little more wary off.
Thing is, that 'stick' welders and MIG welders are both ARC welders, they create a VERY hot 'arc', that is JUST as hot as a gas flame, an awful lot brighter, AND is made from a completely exposed current of electricity.
You wouldn't want to be holding onto a spark plug coupled to the coil when it 'sparks', would you? You'd be worried about getting a 'jolt'. Well, a spark-plug 'pops' with perhaps the power of a domestic light-bulb, maybe 100w. An Arc welder, running on chassis gauge steel will be running continuously with a power draw of something more like 3.5Kw, about as much 'juice' as you can suck through a domestic mains supply without melting the the sockets!
Old electricians adage: "It's Volts wot Jolts, Mills wot Kills" Which may need a bit of explanation, but the 'Mills' they are talking about are Milli-amps. Power is Volts x Amps. Spark-Plugs work at very high voltage, maybe a few thousand or more, so the 'jolt' you can get off one is quite big, but the ampage is miniscule. It will make you jump, but it shouldn't scorch you.
Electric welding sets, rated by their 'ampage' are actually a big transformer, that steps the voltage of the mains supply down from 240v to something like a few volts, but correspondingly bangs the ampage right up. Typical Welding set, might be rated at around 130A. Open the plug on the end, and you'll find it contains a 13A fuse, so if the transformer has bumped the amps up by times ten, then it will have dropped the voltage by times ten, and it will be running at something like 24v.
It WONT give you a very big jolt, BUT, with something like 30x the power, and probably a million times amps, an electric welding set is very good at turning solid steel into a pool of molten metal very quickly.... just think what that same current could do to bits of your body!
When I made this suggestion in answer to a query on one of the forums, I was harangued by comment accusing me of scare mongering, or being a subversive ally of the safety police..... Sorry, but I don't care! Or actually I do, depending on which way you look at it!
Thing is, I want you to take a couple of minutes to get some kind of appreciation of the forces you are dealing with, and the idea of handling a walloping big electrical transformer that can almost instantly melt metal. It SHOULD galvanise one to pay it a little respect!
Which is ALL I want to do; JUST because you can walk into the shop and buy on of these things like a dishwasher, DOESN'T mean that you can take it home, plug it in and start using it like you would a dishwasher. It IS a piece of industrial equipment, and should be treated as such, and industrial levels of caution applied.
And I say that because I DO care. This site is all about sharing my enthusiasm for mechanics with my fellows, and passing on what encouragement or advice I might. And I REALLY don't want any-one to get carried away and either badly hurt themselves or do an awful lot of expensive damage.
OK, well, the subject of welding rears it's head quite frequently, usually whenever some-one discovers that their beloved vehicle has structural decay that needs cutting out and replacing with good metal, and is given an estimate for a professional mechanic to remedy that rot, that is rather frightening.
In the magazines, nice colour pictures of welding sets, advertised as including 'all you need to start saving money', for as little as £99...... And it seems too good to ignore. It is, too good to ignore, BUT, whether it is a 'good idea' or not, 'in practice', is another matter! And if THAT is your starting point, then, sorry, but the BEST advice I can offer, is DON'T DO IT!
Welding is an art, and not every-on can master it. I've been doing it years, and I never have. Some pick it up and have a natural 'eye' for the craft, others, no matter HOW much they try will NEVER manage to draw a decent joint! And, as a starting point, renovating a rusty old chassis or worse 'unitary' monochoch body shell, is JUST about THE WORST place to begin!
If you sign up for a 'course' your starting point will be on nice thick 'chunks' of mild steel, probably half an inch thick, that you 'prepare' on a bench in a vice, and then weld into any of the various joints, on a bench, in a booth, with the bits all neatly clamped up. As your proficiency increases, you will gradually work your way down from thick 'duplo' sized chunks of metal to thin plate, which you will blow holes in, get twisted and distorted and variously foul up. And that is nice neat 'test' pieces, joined in ideal conditions.
At home, on your drive, or in your garage, you will be looking at horrible gaping sores of rust, with jagged edges, in panels or sections that are usually not nice regular shapes, but ruddy awkward ones, and you wont be working in a booth or on a bench, but probably lying on your back, in a cramped space with no elbow room!
And your FIRST problem will be to cut back the 'wound' to find good metal, that you can actually weld to. Faffing about with an angle grinder, in that tight awkward space. But, having cut back to good, you then have to make up a repair patch. Which means getting some plate of the same gauge as the metal you want to patch and forming it to shape to fill or cover the hole.
Not always that easy, though you may be lucky and be able to buy pre-formed repair sections that can be trimmed to suit. And then there is the joint type you are going to make. If you are working on a floor pan or chassis, somewhere it's not going to be seen, then you can make life a little easier patching 'over' the hole with a 'lap' joint around the edge, but the tricky one, is patching some-where 'cosmetic' like a sill or a wheel arch, where it will be seen, and you may have to be a bit handy with the dollies and hammer to beat your own patch panel, then weld it in with a butt joint, so that you don't have a horrible 'step' for all to see.
It is the bane of the pursuit, but far too many amateur mechanics get carried away, dash out and get themselves a smart MIG set, and try to 'Teach' themselves to weld tackling JUST such 'projects'! There are old Morris Minors, Triumph Heralds, Spitfires, MG Midgets & MGB's the length & breadth of Britain, and dotted around North America, the 'victims' of such enthusiasm.
Every time I pick up a copy of 'Practical Classics' they seem to have found one; and after buying it to do a 'featured restoration', get down to the 'structure' start cutting back the rust, and patching in new sections, only to run into 'old' repairs that thy have to cut out and re-do. Almost inevitably, they comment that HAD they known how bad the old repair work had been, on top of the rust they had observed, they would have NEVER undertaken the 'project', or at least not attempted to repair it; they would have bought a new chassis or shell!
And THOSE are the survivors! The ones running around with shiny paint and ill fitting doors! I hate to imagine how many are still lurking in peoples back gardens, or garages, as 'unfinished projects' or given up on and sent ignominiously to the scrap heap!
Odds of success? If you start with a vehicle that failed it's MOT on enough 'structural' rot for you to try and offset the cost of a cheap welding set against what thee garage have quoted to plate it, having never drawn a weld, and with the idea that it would be a good opportunity to 'Learn' the craft; I'd lay 100:1 AGAINST you getting that vehicle through an MOT within a year, and I'd give 10:1 that the car is likely NEVER to to see the street again! Honestly.
I'm not being pessimistic, I am not trying to put you off, but IF that is your starting point, then THOSE are realistic odds. About one in a hundred people that rush off to get a MIG to get an old car through an MOT, or start a restoration project, ever actually succeed. And I am afraid to say, that most that DO don't do so without help. At some point they will realise just how optimistic they were, and they either go get some instruction, or they get some expert help to actually do some or all of the work for them. So!
Intelligence is the ability to learn from ones own mistakes, Wisdom, the ability to learn from other's mistakes! So lets get wise, and learn from all those 'unfinished' projects. IF you want to learn to weld, don't try and kid yourself that you can teach yourself, or pick it up as you go along, and try and fool yourself with 'false' economics.
Professional welding is expensive; ammeter welding sets, cheap. Reason that professional welding is expensive is because it IS difficult, but...
I can weld. I'm not brilliant at it, my 'cosmetic' welding is absolutely dire, but I AM proficient enough to make 'good' structural joints, that would satisfy an MOT examiner, and have a training certificate some-where to attest to that. However, I DON'T! When any of my cars have needed structural welding, I have got it done by a 'professional'.
Yes, I COULD have done it myself, BUT, by the time I had made enough practice joints to 'get my eye in' again, and have confidence that I could tackle a structural repair, I would have wasted so much time and material, as to not make it worth while. Bit harsh on myself probably, but when it comes to the structural integrity it is best NOT to take chances, and waving a welder around, FAR too easy to make more problems than you fix. So, I have the skill, I have the kit, but even I think twice about tackling structural repairs.
So, IF you are starting out with an MOT fail docket, or starting a restoration project, think twice, and if you are wise, cut out that initial learning curve that is likely to lead to either a disaster, an utter failure, the assistance of an expert, or a training course.
If you JUST want to get your motor through it's test, and reasonably soon, then probably best to bite the bullet and pay a 'Pro' or seek the assistance of a practiced amateur who will help you out as a 'favour'. (If the latter, though DO make sure that they ARE practiced and genuinely competent!)
If you want to learn to weld, then go check out your local College of Further Education, and see what they have to offer, and enrol yourself on a course of evening classes, and treat it as an entirely independent exercise to the renovation work on your car.
There are blokes, (and more than the odd lass, I ought to say!), on the Forums, and in the arena of the motor enthusiast, that have the 'knack', and who don't bat an eyelid at tacking structural welding, and there are the artists of the craft that seem to have angle grinders for finger nails, exhale argon mix and spit welding rods, who can draw a joint like Michael Angelo drew pencil lines! And many of them insist that welding is 'easy'! To them, it is. They have 'the gift'
For most, it's a bit different; now I mentioned that I did my certificates while studying to be an engineer, which was when I was about nineteen or twenty. I had been welding though since I was about fifteen, learning at old 'Pops' elbow, before convincing the CDT teacher at school to let me loose with the Oxy kit on my GCSE project, and later, electing to take a welding course in 'recreational studies' when I did my A-Levels, where, while most made test pieces or a tool box... I made a 'Go-Kart'!
Any way, as mentioned, starting point is some 'theory', then some 'safety', then onto some 'Duplo' test pieces, before refining your skill and tackling detail work. Some have the gift, and pick it up very quickly and very easily and make every-one else sick! Some, no matter how hard they try, can NEVER draw a decent joint, and MOST need a LOT of help and a LOT of practice before they get the hang of it. It IS hard.
And, I should mention, and it was something that a number of my Tutors also noted, the students that most readily absorbed all the 'Theory', and could tell you exactly what the book said about rod angles, or fillet radius, and could quote the dimensions of the joint angle, were USUALLY the ones that struggled most when it came to actually putting it into practice. Ones that struggled most with the theory, though, were usually the ones that most easily got the knack of actually making a joint in the metal.
Which is a caution, because IF you do all the reading about welding, and think that good enough preparation, without training, chances are you are in the former group and are going to find the actual job the hardest. So, I REALLY advise a welding course as your starting point, rather than books or video's or anything, because it will VERY quickly let you find out if you ever stand a chance of getting the 'knack', but not only that, it will let you discover whether you actually ENJOY it!
Remember, this is a 'hobby interest', we are working on our cars as much because we enjoy it, as we do because it saves us money. If we are no good at it, and we don't enjoy it, it probably WONT save us any money, and wont give us very much satisfaction persevering at something we just cant succeed at, and we might as well go fishing!
Next up, having HOPEFULLY, discovered that we do enjoy it, and have some reasonable chance of acquiring the skill, if not 'the gift', training will give you the chance to practice and develop the craft until you have a level of proficiency and confidence to be able to tackle the kind of jobs you envisage in your 'project' at home. And MORE, doing a course, SHOULD best answer all your questions about the 'Best' kit to tackle those jobs with.
Night School class vary a lot in price these days, but an introductory 'short course' over about six evenings should only be about £30 or so, and full years course with professional standard certificates at the end of it, shouldn't be any more than an ammeter MIG set, maybe £150 or so.
An 'Intro' course, really has to be just that; but it is a good way to get the basics and 'have a go'. A 'Full' welding course, will probably cover a lot of stuff, like 'construction' welding, making steel framed buildings, or industrial welding, jointing stainless steel, and things like that which might be a long way beyond what you want or need for welding cars, but the certificates at the end of it are worth having.
A little more appropriate, IF your local college offers them, may be 'motor vehicle mechanics', rather than pure welding. In the MV prospectus, there will be the part time courses for professional mechanics to do on 'day release', as well as full time courses, as well as courses more tailored for the 'amateur'.
Its worth looking into carefully, and discussing with one of the tutors though, because the courses are often 'modular' and you may be able to just pick the modules that are most suitable, from the 'professional' curriculum
In the 'amateur' curriculum, though, you are likely to find 'specialist' courses, like 'car restoration', which again is likely to cover a lot of stuff you might not be interested in, but again, is likely to be 'modular' and let you pick the bits you are.
Two complimentary subjects to welding you may want to look into are also, 'metal fabrication' and 'panel-beating' or 'coach-work'.
Panel beating, is probably the more appropriate, and the skills it involves are basically forming sheet metal into complex shapes with hammer and dolly. It's a lot like welding in being an acquired knack or gifted ability, but if you can beat the side of an old washing machine into a wing panel for an old Austin A40, you shouldn't have much trouble making up repair sections for anything you may want to weld! And it often includes more complicated welding, specific to car bodies.
Metal Fabrication, is more general, and includes the basics of forming sheet and strip, folding and rolling and making seams and the like, as well as basic jointing like bolting or riveting, and often basic welding, and can be the 'closest' starting point in some curriculum.
'Coach-work' is something that can vary in definition a lot. Strictly, 'coach-work' is the entirety of making and fitting out vehicle bodies, so a large part of it may be panel beating, but it can also include a lot of structural metal fabrication to make 'frames', as well as woodwork, for wooden bodies, and the needle work and textile trades needed to upholster and trim an interior! However, in most college curriculum, 'coach-work' will tend to be either a part or an extension of panel beating, and will usually confine itself to the upholstery and trimming of interiors. I mention it though, because some colleges might cover the most appropriate bits of tin-bashing and welding for what you want in a coach-work course, so its worth looking into.
Well, having so HEAVILY advocated professional training as the almost essential start to welding, I have to face up to the 'real world' And half of you are probably already hurling excuses at the monitor as to why that advice isn't appropriate! Anything from 'I haven't Got the Time', through to 'Its not worth it for the LITTLE bit of welding I want to do', or 'nearest college if thirty miles away'
Hold up. Listen to yourself, they are EXCUSES, stop trying to find reasons for NOT giving yourself the BEST starting point you can, and try finding some ways that you MIGHT! If it is seriously impractical to go get some professional training I can offer some pointers to give you a 'better chance', but you REALLY are starting from the back foot
So I'll start with the worst case, going it alone, with a 'Hobby-Set' bought off the High Street from a spotty teenager that can barely us the cash register, let alone the welder you just paid for!
Before you do ANYTHING else, leave the darn thing in the box for a bit! Do as much research here on the net as you can looking for 'welding instructional' articles, and book-mark them all. Check your local library and book-store for 'teaching yourself to weld' books and video's, get them, read them watch them, and learn from them.
Then, BEFORE attempting to weld ANYTHING with wheels, let alone anything you might intend to try driving! Go find some scrap. White-goods are good, old washing machines, tumble dryers, cookers, that sort of thing. They tend to be made from the same sort of gauge steel as cars, and are normally nice cube shapes with flat sheet sides you can easily take or cut off!
This is worth noting, because, as an amateur welder, old white goods are a BRILLIANT source of cheep steel! Halfords and Machine-Mart are VERY quick to sell you a MIG set and welding wire, but they DON'T actually stock sheet steel, and they often cant even tell you where you might get any!
Yellow pages. Have a look in the 'phone book and see if you can find anything under 'sheet steel' of 'metal fabrication' or ;industrial materials', but be warned a lot of stockists don't like dealing with amateurs, and may insist you have a trade account, or buy a minimum quantity, and when you turn up to collect a 12ft square sheet of tin with a Nissan Micra, are likely to tell you 'Sorry No, we don't have anything to cut it down to fit in your boot'! after they have charged you what seemed like rather a lot of money for it!
When you DO come to try sourcing steel, worth looking around and talking to people, and a wander round a local industrial estate can prove very helpful. If you are lucky, you'll come across a metal fabrication business or body-shop, that will supply you a convenient sized sheet of tin, more happily than a metal stockist, (Often for a small contribution to the works 'social fund'), better still if they will let you have old off-cuts or let you rummage in the scrap-skips for them. For panel patches, you often don't need a large sheet, and a big enough off cut might be all you need.
But, for now, pull that old cooker to bits, cut it up and try sticking bits of metal together with your metal glue gun! Be careful on bits of old washing machine, they often galvanise the panels on those, and you'll need to grind back the plating a long way from where you are going to make a joint, but you'll have to prepare the metal similarly, any way. If its an old chassis or car panel, you'll have to cut back the rust, if its a bit of old cooker, you'll need to strip back the paint or plastic coating.
So its all good practice, and THAT is the key. Practice. Practice, practice and MORE practice.
When you have a big pile of steaming scrap at your feet, made from old white goods, and reckon you are about ready to tackle bits of a car....... STOP looking at your pride & joy!
Head to the scrappies and get yourself a REALLY rusty old tail gate from an old hatch-back, and maybe a couple of rotten doors. Maestro & Montego's are good candidates! Tell the tatter what you are doing, that you want them to practice welding on, so the more rotten the better, and he'll probably let you have them for free!
Take them home, and try patching some of the holes, see how you get on with the complex curves, then find some of the more 'awkward' wounds to tackle, ones where an edge or lip has rotted away, or the wound is right on a corner, your repair patch would have to bend round.
When you have expend the entire roll of welding wire that came with your set, and the gas, and replaced them with the larger 'budget' sized roll and canister, and exhausted those.....
IF you are happy that you have got the hang of it, you MIGHT just about be ready to tackle your car on the stuff that ISN'T structural! to get used to doing the same thing in awkward spaces and positions!
And THAT is about as much advice as I can offer. DON'T dive in or be too hasty to tackle the job you want to do, get some old scrap, and waste LOADS and LOADS of welding wire and gas practicing before you tackle anything important!
Only other alternative, a sort of middle ground, if you cant get 'formal' training, is to get 'informal' training, from another welder. But, how good their training may be depends a lot on how good a welder they are to begin with, AND how good they are at teaching their skill. Better than nothing though.
If you do decide to try and get some-on else to show you how to weld, though, don't use it as a substitute for 'boning up' with whatever you can get to read or watch published by an 'expert'.
'Practicing' welders can probably show you a lot of things that aren't in the exercise books and give you some very useful tips and pointers, but chances are that they will 'skip' over stuff that they think so simple or inconsequential, or is so much second nature or habit, they never give it a thought; could be important to you though, and probably covered in the books and vids.
And if you can, don't just get ONE welder to show you the ropes, try and get a couple to give you some instruction, so you get a second opinion, and don't learn all one blokes 'bad habits' as supposedly 'good practice'.
Really, that's about it. I don't want to go off providing examples of my welding, or giving detail advice. I RALLY want you to think long and hard about WHY you are considering welding, and to decide whether its an economic expedience to get a car through an MOT, or if it is a skill you really have an interest to acquire.
I DON'T want you rushing off and buying yourself a hobby welding set, that you cant use, or that you end up doing a lot of damage with before you master it, or worse causing yourself injury.
I'd LIKE you to go and get formal instruction, and learn to do the job 'right', and be able to tackle the jobs you have in mind with the confidence that you CAN successfully complete them.
But if you REALLY cant get formal training, then try and get some 'informal training' and at least get some-one who knows what they are doing to 'show you the ropes', better still, a few.
If you are UTTERLY stuck and HAVE to go it alone, read everything you can, watch everything you can, and practice on as MUCH scrap metal as you can find or afford, before tackling anything 'important'.
And with that, I offer you a brief article I clipped from an old magazine a few years ago, for the joint diagrams!
An Article from, I think 'Classic Bike' Magazine, around the early '90's by Peter Watson
If you want to join two pieces of metal together there are many different processes to choose from. Adhesive bonding, rivetting, soldering and brazing are just a few. But the one that is likely to be the most permanent — because the two separate bits are actually fused together in a molten pool of metal — is welding.
It's important not to confuse brazing with welding. In brazing, and the same goes for soldering, neither piece of metal is melted. Instead, the two pieces of metal are joined by melting a brazing rod into a tight-fitting joint. A metal filler rod of very similar appearance is also used in welding, but this is only applied to the joint after it has been made by melting the parent metal together.
Because of the composition of the brazing rods often used for frame construction, some people talk about 'bronze welding' rather than 'brazing'. So if someone says that a motorcycle frame is 'bronze welded' think: 'brazed, not welded'.
For motorcycle frame construction brazing has two advantages. It requires less heat than welding, reducing the risk of the distortion that can be critical with the thin-walled tube used on racing chassis. And a brazed joint is less brittle than a weld, making it better able to withstand flexing.
Walk into a Machine Mart showroom or send away for a catalogue and the choice of welding equipment looks daunting. Don't despair, for the basic decision is as simple as choosing a cooker for the kitchen— gas or electric?
An oxy-acetylene gas set has one major advantage: versatility. Because no electric current is required, you can take it anywhere. And when it comes to dealing with heavy gauge metal, where a single -phase electric MIG welder may be operating at the upper limit of its range, a larger nozzle on the gas torch may be all that you require.
However, it's probably harder to learn to weld with gas rather than an electric arc, and if you do use that big nozzle you'll be driving down to the BOG depot for recharged gas bottles pretty frequently. This is because the affordable BOG Saffire Portapak welding sets come with smaller oxygen and acetylene cylinders than the type used every day by the professionals. Oxy-acetylene equipment has many uses outside welding. It can be used to cut metal, join dissimilar metals by brazing, fill rust holes with braze and even gently heat up stubborn nuts and studs.
Instead of mixing oxygen and acetylene gases and lighting a welding torch, you can strike up an electric arc. There are many different types of electric arc welding, but all operate on the same principle. The welding set is powered from a transformer with two leads. One — the earth lead — is fastened to the work, while the other goes to the electrode. This can be semi-permanent or consumable, with wire automatically fed from a reel. As you lower the electrode down towards the work an arc jumps the small gap to complete the circuit.
Unlike gas welding, the heat is localised, reducing the risk of distortion. Filler metal in the form of a rod coated with flux to remove impurities and oxides is used, as in gas welding. The amperage is altered to suit both the thickness of the metal to be welded and the electrode diameter. The most popular types of arc welder today are MIG and TIG welders.
MIG stands for Metal Inert Gas. The electrode is a wire-fed and shrouded in a gas (argon /oxygen /carbon dioxide or helium/ argon /carbon dioxide) envelope that both shields the weld pool and electrode from contamination and cools the metal. TIG stands for Tungsten Inert Gas. This time the tungsten electrode is semipermanent.
There's a multitude of MIG welders aimed at the DIY market, but far fewer budget TIG sets. TIG is favoured for exotic light alloys and very thin metals but both MIG — suitable for both aluminium alloys and steels — and TIG welders are quicker and more accurate than a gas torch.
A variation on the MIG for use out of doors, where the gas envelope may be dispersed by wind, is the gasless MIG welder. The continuous-feed wire electrode is cored with chemicals which burn to provide a gas shield.
BOC's gas-welding Portapaks start at just over £200. The company's Migmaster 130 Turbo single-phase MIG welder costs less than £250
Where to weld: Anyone who starts welding in a wooden garage full of motorcycles is asking for trouble. Ideally your workspace should have a cement floor and walls and a fire-resistant roof. Clear anything combustible well out of the way. Make sure that pets, small children and visitors are kept out of the way, as their eyesight could be damaged, especially if you are using an electric arc welder. If your garage is attached to the house, think twice about welding inside it. Losing a workshop is one thing; don't risk your home. Invest in a big foam or dry powder fire extinguisher and a fire blanket.
Gas welding is more hazardous for two reasons. The extra risks of working with a naked flame are obvious. And gas bottles left in a blaze become bombs. Finally, think about what you're welding on. Quarter-inch steel plate is the stuff to have under the job, not a lump of stone, which will splinter in all directions.
Buyer aware: Many claims are made for welding machines designed for the DIY enthusiast. You may be concerned, for instance, about the thickness of metal that a single-phase MIG welder can cope with. There's a simple way to establish the truth of claims, says Derrick Hilton of BOG Gases. 'Ask for a demonstration/ he says. 'Take along the sort of work you want to do and ask to have a go. It's the only way to establish what's right for you.'
Don't burn out: If you do burn yourself welding, first-aid is simple. You need to lower the temperature of the burned area at once, so forget butter or greasy proprietary creams . These will only make matters worse.
Hold the affected area under a running cold tap for at least ten minutes and preferably longer. This will feel like a very long time, but persevere because you are doing the right thing.
How do I know? Last year I burned my arm badly with a hot-air paint stripper. Cold water works. The burn didn't hurt and healed quickly.
If you can't hold the burned area under a tap, fill the bath with cold water, jump in and stay there.
Back to school: You can teach yourself to weld with the help of books and videos, but most local colleges in the UK offer evening classes in welding. While professional tuition is helpful there's no substitute for practice. Get yourself some scrap metal and work on creating the molten pool of metal that you slowly drag along to produce a joint. You will discover that anything to be joined together must be securely fixed before welding starts. Vise Grip C-clamps are the answer as they're as versatile as a pair of Mole Grips and relatively inexpensive at £15 or less. Even when the different pieces of metal are clamped up securely you will still need to 'tack' the job together with short runs at each end before starting to weld in earnest