n my adventure of building an allaluminum Zenith 601XL kit, I have learned many new skills. Working with aluminum, as I expected, is where I spend most of my time. My first deviation from aluminum work was a rewarding exercise with fiberglass [See “Composite Wingtips 101” in the

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the arc-welding options and uses a stick or rod electrode to make the arc. The rod becomes the filler material, as it’s coated with a flux material that’s consumed along with the rod while making the arc. I found stick welding to be of medium difficulty to learn. •MIG or metal inert gas welding

TIG welding, but you control heat by adjusting and handling the flame. I give gas welding an easy-to-medium rating on the learning scale. So which was best for my application? Stick and MIG welding lack heat control, and the hot, fast arc generated would obliterate thin-wall 4130 steel.

Gas Welding for the Non-Welder, Part 1

A Zenith 601 builder presents a beginner’s guide to basic gas welding. BY SCOTT LAUGHLIN

March 2004 issue—Ed.]. Recently, I ran into another nonaluminum task for my project—welding 4130N chrome-moly steel tubing to build my rudder pedals and other flight controls. Welding metal had always been a bit of a mystery to me. What better time to examine the basics of gas welding from the perspective of a true beginner?

Four Ways to Weld After doing some research, I discovered four options for welding at home—MIG, TIG, stick and gas welding. Three of these methods use arc welding with a machine plugged into an AC outlet. The parent metal is grounded, and you create a short to make the arc to heat and melt metal. If you have ever hooked up a pair of automobile jumper cables and accidentally touched the two free ends together, you get the idea of arc welding. The cost of equipment for these four types of welding processes varies greatly depending on how fancy the unit is, but here’s how they rank for low-end hobby use from least to most expensive: stick, gas, MIG and TIG. I’ve experimented with each type to some degree, so here’s a brief explanation of how each works: •Stick welding is the most basic of PHOTOS: SCOTT LAUGHLIN

uses a wire-feed device to advance the filler material—in this case, a roll of thin wire. The filler material makes an arc and melts along with the parent material. An inert gas such as argon is used for flux. I call MIG welding point and shoot welding. It’s well suited for welding 1⁄8-inch and thicker steel. You can also use this equipment without the argon gas if you use a flux-core wire. MIG gets an easy rating on the learning scale. •TIG or tungsten inert gas welding is the most complicated and considered by many to offer the best heat control. As its name implies, inert gas is used, similar to MIG welding. TIG’s main distinction is that it uses a tungsten electrode that does not melt when making the arc. You add filler material with one hand while making an arc with the other hand. In addition to using both hands, you use a foot pedal or finger adjuster to control the heat. This is the most popular type of welding used in professional fabrication shops. TIG leans toward the difficult end of the learning scale. •Gas welding does not use electricity and makes no arc, instead using the heat of burning gases to melt metal. Torch design plays an important role in this type of welding. You add the filler material with your free hand similar to

TIG welding is well suited for thin steel, but the equipment is costly at around $1500 for a starter unit. It didn’t take me long to conclude that gas welding was my best choice for thin-wall tubing, considering my budget and ability. I had never seen anyone weld with gas, so I was intrigued. The following is a summary of the challenges and rewards of my experiences in putting together the equipment and learning gas welding.

Cylinders and Gas Gas welding is accomplished with oxygen and acetylene. Welding and cutting with oxygen/acetylene has been around since the early 1900s and was a major breakthrough at the time. Back then, acetylene was hard to come by. We are fortunate today because it is readily available and easily stored in high-pressure cylinders. My first objective after deciding to learn to weld with gas was to obtain a set of cylinders (also called bottles) so I could practice at home; I discovered that most welding supply stores rent or sell bottles. I asked my local welding store if they would fill or swap bottles if I purchased them from another source, and, to my surprise, they readily agreed. I chose to buy mine via mail order and saved about $100. The empty oxygen

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Gas Welding CONTINUED

container cost $114 (shipping included) for an 80-cubic-foot, shiny green bottle. The acetylene bottle cost $60 (shipping included) for 40 cubic feet of capacity. I had these empty bottles in my possession for only a short time, however, before surrendering them for two scratched-up bottles full of gas. The cost of the gas was $12 and $17 for the oxygen and acetylene, respectively.

Life is too short to fly anythıng less.

www.seqair.com For complete information, send $15.00 ($20.00 overseas—checks on U.S. Banks) to: Sequoia Aircraft, Dept. K, 2000 Tomlynn St., Richmond, VA 23230. Visa/M.C., call (804) 353-1713. Fax 359-2618.

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