General Welding equipment

MIG Welding

Garage power supply?

Nicola&Tony: I've recently started doing a welding course and have read quite a few threads on the subject on here, 
so I'm now thinking about buying a 150 amp mig welder.

Just one question at the moment; will I be able to power it by plugging it into an ordinary household electrical socket / circuit, or does it need to be on a circuit that's a bit more heavy duty? Tony

andysimpson: May have problems on full power, try it and see.

steveo3002: Should be fine...no need for full whack for welding body panels etc.

DiscoDave: Usually it'll work on a 13A socket plugged in to a normal socket. I've got a 150A mig i plug it in to a 16A blue socket that i've put in out side! You'll only have problems using it on its highest power setting, unless your wiring in the house isn't up to much!

dugcati: Can vouch for it being OK short term on 13A plug... I have a 165A welder and it's fine HOWEVER!.... I wouldn't advise using it for too long on higher power on a standard plug and wiring as it WILL put strain on the cabling and start to burn out the pulg/socket!

oldiquana: My biggest welder in't workshop is 185 amp.....running on normal 13 amp sockets......never had any problems really...as long as it's a good quality unit it should be OK on full power as long as you dont go daft. Just to be sure I installed a separate outlet from the main electricity supply to the house then seperate isolator unit then seperate RCB in the workshop via armoured underground cable. The compressor seems to load the supply more than we welder though!. I have to run two welders for everyday use....my 185 is set up for heavy guage gates/railings etc...but for panel and repair work I love my Clarke 100en......more than enough for car repairs, with settings low enough to weld toilet roll... if need be!

Pepperami: I have a clarke 151TE and thats fine (on 13A) but I want a TIG

Nicola&Tony: Thanks ver much for all the info.

Bought meself a welder off ebay today and will pick it up on the way home from Cromer in a couple of weeks time. It's a Cosmo 170 gas/gasless mig with two full gas bottles (small), regulator, auto-darkening helmet, angle grider and discs. All for £140 and listed as being "in excellent working condition" . . . I hope it proves to be as good a deal as it sounds! Tony

Gasless MIG (flux cored)

Rozzo: Anyone know if the gasless mig wire is any good? Seems like a great idea but never actually seen it in action.

lloyd: No expert, but MIG = Metal Inert Gas and leave a slag free weld. Flux core MIG isn't really MIG. It's more an auto feed arc weld. I've used both as well as flux core wire with inert gas. Flux core doesn't require metal to be as clean and can be used in low wind. MIG will not. Sorry I can't help more.

mininut: Personally I wouldn't bother with gasless. Agree with what lloyd said really. MIG should be gas shielded.

BUT if you can only weld outside you'd probably be better with gasles

TIG Welding

TIG = Tungsten Inert Gas (or GTAW, Gas Tungsten Arc Welding) uses a tungsten electrode (non consumable) to create the arc, uses an inert gas around the arc for shielding, but uses a separate filler rod (like gas welding), making it the most versatile welding technique, as almost any filler rod to match the weld material can be used.

TIG welding equipment is a big step up from MIG, and is the preferred method for high quality welding of either thin or exotic materials (non-ferrous) for structural purposes. It's used a lot in the aviation and spacecraft industries, often manually or semi-automatically. Also many modern duralumin and titanium bicycle and motorcycle frames and parts are TIG welded.

Its considered one of the hardest welding skills to acquire, requring very steady and accurate control of both the 'gun' and filler rod. Unlike MIG, the power level can usually be varied as the weld takes place, decreasing as the edge of the material is approached.

Although a lot more expensive than MIG, the equipment isn't that much more bulky, and isn't out of the question for Home workshops.

NB. Safety wise, TIG is more dangerous than MIG having even higher UV light emissions and can give bad (sun)burns to exposed skin, as well as high ionisation of air, and production of noxious gases if contaminants are present.

So TIG welding eqpt would usually be restricted to indoors/workshop environments, onlookers face higher hazards than with MIG and much higher than with gas welding.

Gas welding

Gas welding has become much less used in the auto-trade, having been eclisped for many, but not all jobs by MIG or stick (arc) welding

It is not generally a Home Mechanics solution because of obvious safety considerations; the bottles require licensing, are getting very expensive to refill, are not particularly portable and gas welding requires more safety/operational training, and then typically more time developing the welding skills themselves.

One criticism is that distortion is much greater than electric welding methods, though not true in every case. Generally though a larger area becomes heated than with MIG or TIG.

In the right hands, lovely welds can be produced, particularly in thick or more varied thickness materials.

One advantage is that UV light intensity is much lower, requiring only a No.3 filter shade, electric welding requiring 9~13 shading, as well as the more consistent light emission, making it somewhat easier to see what is happening at the weld pool. However, the advent of auto-darkening helmets for electric welding has made a big difference to the ability to start and pickup the weld area rapidly though.

Gas equipment can also be used for brazing (bronze welding), which is a form of high-temperature soldering. Until recently, almost all bicycle and motorcycle frames were brazed. Less-heat and a sweated joint design gives very high strength, but a higher accuracy of fit is required than welding. With a strong flux, brazing can clean and scour quite dirty metal, yet generally is said to require very thorough preparation.

Today, many garages, general workshops and body shops only retain their gas welding eqpt. for heating up parts, to form them or to remove old/rusted fasteners e.g. exhaust fitting shop. Tht is, a very quick, powerful and focused heat source.

Because it involves more skill to ensure a good strog weld with adequate penetration, gas welding has become less favoured for structural repair work...