TECH NEWS. Society of North American Goldsmiths Artists Designers Jewelers Metalsmiths October by Sean Macmillan. Process

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1 Society of North American Goldsmiths Artists Designers Jewelers Metalsmiths October TECH NEWS This issue s Technical Article is a basic introduction to using TIG welding on non-ferrous and ferrous metals. Though by no means a complete guide to TIG welding, hopefully it will inspire some of you to explore the possibilities. I know many schools have TIG welders in their sculpture departments and more and more are buying the rigs for jewelry and light metals. Enjoy, Jim Bové, SNAG News Technical Editor T I G W e l d i n g f o r M e t a l s m i t h s by Sean Macmillan Writing an article about welding for metalsmiths can make one a little nervous. To me it is like trying to give woodworking advice to my father, who taught me how to work wood. I know quite a few of you out there use welding, and have been doing it for years, please feel free to share your tips and advice with me and the rest of the metalsmithing community. Background Since my first semester of graduate school, I had been attempting to work in a larger scale. The first large-scale piece was approximately four feet from end to end and had been assembled using Sil-phos plumbing solder. It was expensive and messy. I went on to trying to silver solder these large pieces, sometimes twenty four to thirty six inches in size, with decent results. But I was disappointed with the silver lines that ran through the pieces, highlighting every seam. Later, when a brand new Miller Syncro- Wave 180 TIG welder arrived at the Metalsmithing studio I knew I had to try it. I watched it sit there, so fresh out of the box that the protective cellophane had yet to be removed, while the school work orders went through to hook it up. It was excruciating. Finally, months later, there was electricity pulsing through the machine and the rest is history. From then on, I tried to find an excuse to weld anything and everything. By jewelry standards, I still work large. The novelty of the TIG welder has worn off. Though I am partial to welding, I am fully cognizant that it is not a savior for everything. There are many cases where I need to employ traditional sliver solder, and recently I have had to resort to some braze welding with an Oxy-Acetylene rig. We must separate ourselves from the technique and materials that we are enamored with and make decisions to support the best outcome for the work of art. I am currently using a Lincoln 225. It has a maximum output of 230 amp and is able to run direct current (DC) and alternating current (AC) welds. Process The basic principle of the TIG welder is simple. It is very much like gas welding, where the torch is just a heat source. In the case of the TIG welder, the heat is produced by electricity instead of flammable gas. It has been my experience that people who are proficient with gas torches (most of you who are reading this) catch on to TIG welding quickly. The torch piece has two major purposes; to provide heat and a shielding gas. In TIG welding, the heat source is an electrode of either pure or thoriated tungsten. This electrode is fit into the hand piece by an adjustable collet that allows you to change the distance of the point of the electrode in relationship to the end of the ceramic cone. The ceramic cone directs the shielding gas (usually pure Argon) to the weld. Typically, I will have the point of the electrode be about 1/4 inch from the end of the ceramic cone. Occasionally, you will need to extend it out further, but you risk an increase in porosity in your weld. The shielding gas is emitted through small holes in the collet s body and is con tained by the ceramic cone. The farther the weld is from the gas, the greater the chances for oxygen to be introduced into the weld. This is a typical air cooled collet, collet body, tungsten rod and ceramic cone.

2 Society of North American Goldsmiths Artists Designers Jewelers Metalsmiths October The electrode should never come in contact with any metal at any time. There is a high contamination hazard that affects the quality of the arc. In most welding applications, the electrode is ground to a point, which improves the ability to focus the arc with a high degree of localization of heat. When preparing the tungsten rod, you must always grind your electrode parallel to the grinding wheel. Grinding the rod perpendicular will cause the arc to spiral and spread. It is recommended that you only use your grinder for tungsten. Grinding other metals with the same stone can cause contamination. Correct grinding technique. Lightly spin Electrode as you grind. Incorrect grinding technique. Electrode should never be perpendicular to wheel. Properly prepared tip for welding copper, steel, etc. Make sure there are no impurities or burrs on tip All work must be clean and dry. If it is not, you risk alloying any impurities into the weld and could cause weakening, color differences and other headaches that will need to be addressed through extra cleanup. Wet work will disrupt the arc, even if only the underside of your metal is wet. A previous tack weld spreading the seam needs to be ground before work can continue.

3 Society of North American Goldsmiths Artists Designers Jewelers Metalsmiths October An angle grinder makes quick work of the old weld and cleans the area to be welded. I tend to take extra time clamping and securing the work to the table. Don t be afraid to move clamps in order to reduce warpage. Tack your pieces in a zigzag pattern across the work. When tack welds are an inch or closer together, finish welding whole seam. The electricity that is being used causes severe UV radiation. You need to protect yourself and others around you from the harmful UV rays. A protective helmet with a minimum of a Shade 10 lens is required. I prefer to work with a Shade 12. I am not a fan of seeing spots when I am done working. Dark, long sleeved clothing is necessary to protect your skin from burns. Light colored clothing will actually reflect light under your visor and cause damage to your eyes. Never weld with your eyes shut. Not only do you not see what you are doing, but the UV rays are powerful enough to pass through your eyelids. I have a hard time with TV programs like Monster Garage and West Cost Choppers that constantly show their stars working with their eyes shut. This doesn t make you tough it will make you blind. Protective gloves are needed to prevent burns caused by heat and UV rays. Use gloves only for TIG welding and do not wear those gloves anywhere else to prevent contamination. If your welder is in a room where others are working you should use protective curtains to prevent others from UV exposure. It is the welder s responsibility to ensure an innocent passerby is not inadvertently exposed to the bright arc. Proper ventilation is necessary. Argon creates an oxygen free atmosphere and could cause suffocation. Most metals, especially copper and copper alloys, will emit gasses that are harmful, or there may be harmful impurities in the metals that you are welding. All shielding gas cylinders should be securely fastened at all times. Clamping the work to a table helps to prevent warpage. Allow the weld to cool to the touch before unclamping. Obviously, there is an electrical shock hazard. Do not put yourself in the path of the arc current and make certain that all protective coverings are in place before welding.

4 Society of North American Goldsmiths Artists Designers Jewelers Metalsmiths October Types of metal for TIG Cleaning copper wire for welding copper to Steel TIG welding can be used on stainless steel, copper, copper alloys, silver, silicone bronze, mild steel, titanium and aluminum. You can weld most dissimilar metals with the exception of aluminum. Typically, you will use a filler rod of the material that you are welding. When welding dissimilar metals, it is recommended that your filler material is of the metal with the lowest melting temperature. Welding aluminum requires different preparation of the tungsten rod and a different setup of the machine. My welder is almost never switched from Direct Current. Direct current, electrode negative (DC-), focuses all of the heat to the work. Most welding applications require at least a 90% DC-setting. Alternating current (AC) basically bounces the current back and forth from DC- to DC+. You need to have an AC setting on your machine in order to weld aluminum. Aluminum s ability to conduct heat requires this setting. AC settings put more stress on your machine since 50% of the heat and energy is being bounced back into the hand piece. It is recommended that you use a water-cooled torch for extensive welding over 150 Amps. Also, it is recommended that you use pure Tungsten and prepare a ball instead of a point at the tip of the electrode. The ball is created by setting the machine at direct current electrode positive (DC+). This is the only time I ever use this setting. It focuses all of the heat to the electrode causing it to melt and ball up at the end. Amps/temperature The amperage setting on your machine functions more like a governor on an engine. The amps are essentially the amount of heat the torch is going to output. Changing the amount of amperage output limits the amount of heat that the torch will emit. Most of the time, I have my machine set to the max output (230 amps). The reason that I have my machine cranked all of the way up is that most of the time I am welding copper to copper, or copper to steel. Steel will heat almost immediately. As soon as your arc starts, you have a nice, clean weld puddle this is not the case with copper. Copper tends to take a little while to heat up so I like to have a bit more heat at my disposal to get the weld going and then quickly back off on the heat as the weld continues. Copper has a few tricky properties. I could spend a little more time pre-heating my metal by using a torch, but my current studio setup has my welder in the basement and all of the torches are upstairs. Also, I am a bit impatient. I rely on the sensitivity of the machine to compensate for my shortcomings. The versatility of the TIG allows me to immediately change the amount of heat that I am using, by simply pressing or lifting the pedal. My left hand holds the torch and, much like gas welding, you can precisely direct the heat from one side of the weld to the other. I rarely have the luxury of welding similar materials of like thicknesses, so being able to control the heat in this way is an extraordinary benefit. Additionally, unlike other welding processes, you have absolute control over the speed of the filler material. If a bead builds too quickly, I can simply choose not introduce more filler material. If I see a hole forming, I can jam more filler wire and plug the hole before it spreads. Copper takes some getting used to. I feel that if you can get the hang of welding copper, the steel and bronze are much easier. It is also a good warm up for learning to weld aluminum. Advantage to Patinas The best part of welding copper in my opinion is the lack of noticeable seams. Sometimes I will leave the seams because the welded texture is so inviting. The lack of seams is wonderful if you plan on applying patinas to your work. I was frustrated with trying to copper plate over silver soldered seams. Now if I am planning on using patinas, my welded seams are the same material as the rest of the work. This piece demonstrates the advantage of using the TIG. I left all welds visible except the seam on the spiculum stem. Because the welds are like metal, they do not become a distraction. Photo: Zaruba & Zaruba Gallery

5 Society of North American Goldsmiths Artists Designers Jewelers Metalsmiths October Scale Welding also allows me to exponentially increase the scale of my work. I don t have to plan and think about a three-foot seam in a piece. I can also use steel as a structural component and essentially weld a copper skin to it to save material and keep cost low. You can also weld a seam, file and sand, then planish over that seam a number of times, and that seam will behave better than a lap joint for further hammer forming. It is a joy to be able to fix cracks in hammer formed pieces and then continue to hammer. You need to make sure that you file down your weld on both sides of the sheet, and then planish a few times over the repair to address the crystallization of the weld. You should still be careful with the area, but you will have significantly less cleanup when you are done. Because the heat is so localized, warpage is always an issue. Typically, an organic, copper form is not a challenge because of the complex shapes and opposing angles and planes. I still employ more of an auto body approach to my welds. I use many tack welds spaced along the seam and I try to work in a zigzag pattern across the work. The benefit is that you get more of the pieces attached with less distortion and the two metals will work together to prevent serious movement. I also spend a lot of time clamping and securing my work to the table. If you need to have a piece remain flat, the longer you can keep it clamped down after you are done welding, the better. I use a large piece of plate steel that was an intaglio press bed. I ll clamp work down, weld the entire seam and then leave it clamped until it is cool to the touch. Welding the Spiculum Warpage This piece of spun mild steel was only heated enough to get the arc going. Notice the amount of warpage caused. Lately I have been using a lot of spiculum forms in my work. Spiculums are difficult to weld because of the reducing amount of material. Typically, the form has significantly heated due to its small size as you make your way to the point where the metal is the thinnest. You can almost guarantee to melt a hole in your material if you try to weld the whole seam at once. I have had success in welding the entire form in the past, but you need to allow the metal to cool significantly. I have found that if I weld the first inch or two of a conical form, then silver solder the rest, it is much quicker and I can still weld the finished cone to other forms. Tack welds on the spiculum and a recent piece Albescent Temper with over twenty spiculums welded to the interior of the form. (7.5 x 7.5 x 42 Steel, Copper, June 2009)

6 Society of North American Goldsmiths Artists Designers Jewelers Metalsmiths October Full Disclosure I need to disclose that I am not a certified welder. I received formal instruction from Jon Havener at the University of Kansas, but I will be the first to say that I still have much to learn. As with most artists, I have discovered much through trial and error. This is what works for me and I have made my discoveries through a number of years of welding. Welding equipment is not cheap. My set up was just over two thousand dollars. I was able to justify the purchase because I needed the tool to complete two commission pieces. Make sure you are going to use this incredible tool in order to justify the cost. There are quite a lot of options and a variety of welders available. I have never subscribed to the Miller vs. Lincoln debate. I learned on a Miller. I own a Lincoln. The older machines will work just fine. For me, size was an issue. Older machines tend to be larger. You can spend as little or as much money as you want, but make sure that you do your research. What are you welding now? How will you plan to use the welder? The best piece of advice that Jon gave me was not to wait as long as he did to buy one. I have adopted quite a few one liners that have their roots in welding technique. My favorite that can be applied to any new technique is, You have to burn a few holes in a piece of metal to understand what it takes to burn a hole in a piece of metal, and work just short of that. I have burnt many holes in metal and will continue to do so. As always, I ask for you to share your unique knowledge and experience with the rest of the metalsmithing community. I enjoy articles like Sean s that introduce and explore a technique or material that many of us may not have tried. Jim Bové, SNAG News Technical Editor SNAG News will pay up to $125 per page (up to 4 pages) for informa tive technical articles aimed at any level from intermediate to advanced, from student to the highly skilled professional. If you teach a workshop, have a clever bench trick or technique of interest to other jewelers and metalsmiths, or have more academically based technical research, please share it with our SNAG community. Send your submission to Jim Bové, 1497 Route 136, Washington, PA 15301, jimbove@hotmail.com REMINDER The deadline dates for reserving your ads in METALSMITH are: November 24 for Vol. 30, #2 (March issue) February 4 for Vol. 30, #3 (May issue). April 21 for Exhibition in Print/ #4 (August issue) July 1 for Vol. 30, #5 (October and Holiday issue) CONTACT Jean Savarese, jsavarese@snagmetalsmith.org