Sunday, November 19, 2006


Give a skilled weldor a source of sufficient heat and he will marry metal. The Greeks were doing intricate bronze work before the birth of Christ and significant quantities of high quality steel was being produced in India not too many years after that Event. By the 1300's European armorers had developed welding techniques that are the equal of the most competent of today's metal workers. Your Volkswagen is a rolling monument to all the metal workers who have gone before.

To maintain your Volkswagen you may have to join the historic ranks of the metal-working clan. From time to time it will be necessary to replace certain brackets and supports that fail due to stress or wear. If your VW has been attacked by rust, often times the most practical repair is to cut away the rusted part and replace it. At other times your bug or bus may suffer collision damage, the repair of which will require you to beat out the dents and weld any tears, or even to replace the damaged part entirely. There are many shops that specialize in this form of repair but the fundamental steps are fairly simple, easily mastered by anyone; strength is not a factor when dealing with metal, so long as sufficient heat is available.

The basic welding tool is the oxy-acetylene torch, commonly called a 'gas' rig. It consists of steel flasks of oxygen and acetylene gas, a suitable cart to move them about and keep them from tipping over, regulators to reduce the high pressure gases and control their low pressure flow to the torch, and the hoses linking the torch to the regulator. You'll need a flint striker to light the flame and dark goggles to keep from being blinded by the glare of molten steel. Leather gloves and apron will help keep you from setting yourself on fire, as well as sturdy boots and a handy fire extinguisher.

The best place to find a gas rig is in the newspaper; buy a used rig. Take the torch and regulators to a shop that handles the brand you've bought and obtain any needed repair parts. Then sign up for a basic welding class at a local school, or prevail upon a friend who welds to show you the ropes; your first project can be your welding cart.

Ideally, welding and the many safety-related rituals that must accompany it are the sort of thing best passed from father to son over a period of years but more formalized methods are widely available. One thing you don't want to do is try going it alone; gas-welding is pretty much a self-regulating procedure; if you do something wrong, it can kill you.

Like so much of mankind's store of knowledge, gas-welding can only be mastered by practical experience; no one has ever read a book, lit his torch for the first time and produced a perfect weld. Thor won't allow it.

Most of us start with a formal course then concentrate on the specific type of welding we plan to do, gaining proficiency through hands-on experience. How long this takes depends entirely on you, but be assured it is a skill that any one can master, and fairly quickly, too. During World War II thousands of American housewifes became weldors, often with as little as five days training. And like riding a bicycle, welding is a senso-kinetic skill involving 'muscle memory,' once learned, it's never forgotten; there is a certain magic in the inner cone of an acetylene flame.

A skillful gas weldor can weld steel or aluminum with equal ease using nothing more complex than the basic oxy-acetylene rig. Given a torch that is big enough (or small enough), the skillful weldor can tackle thick structural shapes or fragile sheet metal with equal confidence. But for general automotive maintenance and restoration there are some tasks best done with the least amount of heat. For those welds you will want to use a modern Metal-Inert Gas rig.

MIG welding is a form of electric arc welding and at first glance appears totally alien to your gas welding experience. But once the arc is struck -- and miggers maintain the arc automatically - - you find the 'feel' is the same; you're dealing with molten metal, just as you were with your gas rig. It's different -- much faster -- yet it's the same; you may successfully transfer the bulk of your gas-welding skills to MIG welding.

MIG welding equipment is too new for many rigs to appear in the want-ads. They show up now and then but anything not a total wreck is immediately snapped up. Your exposure to gas welding will have put you in contact with welding equipment suppliers. Here in the States, Hobart and Lincoln are two of the most common names but MIG equipment is also available from mail-order outfits such as Harbor Freight, Sears and J.C.Whitney.

The modern MIG welding machine uses an electronically switched power supply. It still contains a husky transformer but the electronic circuitry allows it to work happily from your normal household mains, unlike older arc-welding equipment that used brute force instead of solid-state wizardry.

Since MIG is a form of arc welding its proper name is Gas Metal Arc Welding, or GMAW. The key-word here is 'gas.' You can also use most miggers without inert gas (I don't recommend it), in which case you'll need to feed it a special (and expensive) flux- cored welding wire. This process is properly called Flux-cored Arc Welding or FCAW. I mention these tags because they are internationally recognized and many MIG machines are imported. If you read the fine print you may discover that what is advertised as a MIG machine is in fact limited to FCAW operation, lacking the control valve and other features that allow it to use inert gas shielding. This is the case with the inexpensive rigs offered by Harbor Freight and J. C. Whitney. In my shop I have gas, arc, TIG and MIG welding capability but for most work I use a little Hobart MIG welder, their Model 120. It cost about $600 a few years ago but has since come down in price. It weighs 30 kilos (67 pounds) and operates on 120 volts AC, drawing a maximum of about 20 amps. I've used it for welding steel from .035" up to half an inch, and for some aluminum work; it will repair a broken fin on a VW cylinder head but is a bit small for general head rebuilding (that is, performing deep, high-volume weldments in cast aluminum, such as repairing a crack between the valve seats; high-amperage TIG is the best choice there).

The little migger is a marvelously handy tool. We've thrown it in the back of the truck with a 1500 watt generator and bounced seventy miles into the boondocks to repair a ranch gate with no more effort than that spent loading the equipment. To do the same with arc or gas meant mounting a major expedition.

A mixture of carbon dioxide and argon works best when welding steel; a 53 cubic foot bottle of mixed-gas costs about $20 and provides several hours of welding time. I use straight argon for aluminum. I'm still working my way up to doing stainless steel with the migger. For different metals you will need different welding wire, which also comes in a variety of sizes. You will also need ready access to the various consumables, such as gas, torch-tips and the like. When you buy a Lincoln or Hobart rig you are buying-in to their reputation for dependable, long-term customer support. It's hard to quantify customer support in dollar terms but without it your equipment is virtually useless; paying a lesser price for an imported migger is often a case of penny-wise but pound-foolish.

Once you gain experience (either arc or mig) 'nodding' down your helmet the instant before you strike the arc becomes automatic. But until you acquire that skill you'll find yourself striking the arc over here when you meant to weld over there. A piece of equipment that every novice weldor should own is, alas too expensive for most of us. It is the so-called 'Clear View' welding helmet. It uses an electronic circuit to darken the viewing window when the arc is struck. This happens faster than your eye can react; you never see the flash. One instant you're looking at the work, the next you are seeing a comfortable view of the arc and the pool of molten metal. The Clear-View helmet is an elegant, albeit expensive, solution; it will make you a better weldor. (I'm still nodding my helmet down... and occasionally welding my ground-clamp to the vise.)


This information is intended to provide an over-view of what may be a new subject for many VW owners. Autobody work is the major expense of any restoration. Time spent learning to weld, and the cost of buying your own equipment, is often the only practical means for many of us to accomplish a restoration. But welding, like spray-painting, presents a host of hazards, many of which are potentially fatal. Mastery of these skills is extremely rewarding and I hope you will at least look into acquiring them. But please do so with thoughtful caution.

-Bob Hoover

No comments: