Welding Basics by Curtis Von Fange One of the most useful skills that an owner of older equipment can have is the knowledge and ability to weld. It seems like the older equipment can do a job, albeit slowly compared to newer stuff, but it tends to break more often. Many of the breakdowns are related to the implements that are being used: the disc, wagon or bushog are among them. Knowing how to fix stress cracks, reinforce weak joints by welding on steel support plates, or cutting and shaping parts and adapters out of raw steel plating is an asset that is worth its weight in gold. For the farm environment there are two types of welding that we will deal with in this series. Arc welding and oxy-acetylene. The latter will also include some pertinent information on cutting torches and fabrication of parts and tools. But we will first cover some basics dealing with arc welding. Arc welding is as the name implies, welding with an arc. Simply put, a positively charged electrode and a negatively charged steel plate commonly called a ground complete a circuit at the end of a welding rod. When the rod is held a given distance from the item to be welded the current jumps the gap creating an enormous amount of heat. The heat melts the rod end and when the rod is manipulated in a certain fashion a puddle of liquid metal will result which can be controlled to make a weld. Of course it is a little more involved than the simple description above, but the basic premise is that simple; electrical current jumping an air gap melts the metal. There are many types of arc welding. A few are carbon-arc, metal-electrode, gas metal-arc, atomic-hydrogen, MIG, TIG, and many others. For our purposes we will focus on two basic types of arc welding; AC and DC. It is difficult to explain the difference in simple, down to earth terms so lets just settle for some of the main differences and advantages of each. AC, or alternating current, is probably the most common and most economical of welders. A good unit can be purchased at a farm store for quite a reasonable price. It will do many simple welding tasks with excellent results. The distinct advantage that AC arc welding has is that there is virtually no magnetic blow, which causes excessive splatter and uncontrollable arcs. The basic features are a good forceful arc, an easy arc to maintain once it is begun, it is great for heavy steel plating because of deep penetration, and is wonderful for welding aluminum. The negative factors are that the initial arc can be difficult to start and that burn throughs on thinner plates of metal can be a frustrating problem. All in all though, a simple AC welder is a good all around tool for general repairs. DC, or direct current, provides for a more variety in welding. Direct current, by nature, can be manipulated in ways completely different than the alternating cycles of AC. One example of this is that by changing the polarity of current flow different welding characteristics can be realized. Straight polarity, when the current flows from the rod to the base metal, provides a fairly standard arc for a variety of metals. Reversed polarity, when the current flows from the base metal to the rod, provides for 2/3 of the total heat to be centralized in the welding rod tip. This superheats the electrode metal and shielding gas from the flux causing the molten metal to travel at a high velocity resulting in very deep penetration to the base metal. These variations in the types of DC units can accommodate welding on thick or thin metals. This can give quite a bit of flexibility when trying to avoid burn throughs with thinner base metals or working on deeper weld penetration on thicker plates. As with any trade there are certain hazards which must be addressed when arc welding. 1. Avoiding radiation from the arc, ultraviolet and infrared rays 2. Flying sparks, globules of molten metal 3. Electrical shock 4. Fumes 5. Burns Protective clothing and specialized eye protection must be used in order to reduce these risks. An arc-welding helmet with protective lens reduces the amount of harmful eye radiation and protects the head from splatter and heat. The hair, hands, arms and other skin surfaces must be covered, preferably with heavy leather to shield out other harmful radiation produced by the intense arc. Don't wear regular coverings like heavy cotton or wool as arc welding is accompanied by flying sparks and molten metal pieces that will ignite such clothing. Also avoid pants with cuffs, tennis shoes, thin gloves, and shoes with thin soles. Avoid electrical shock by working on a dry floor with thick rubber shoes and by wearing dry leather welding gloves. Also make sure to use insulated electrode holders and have the equipment properly grounded. Keep the area properly ventilated to avoid inhaling the burnt fumes. The fumes generated in the welding process may contain highly toxic metal oxides. Keep in mind that you are welding with molten metal. The arc is hot, the metal is hot, and everything in contact with the metal is hot. Watch for falling metal globules; they burn quickly through tennis shoes and unprotected pants. When done welding use tongs to pick up the metal; it does not cool quickly and even when quenched in water beware of the superheated steam it produces when dipped and the heat it retains when removed. Above all be aware of others around you. When an arc is struck to start welding the sudden flash can cause severe eye damage to onlookers. Continued observation will quickly cause irreversible blindness. Keep people away from the project. Protect them as well as yourself. Welding Basics, Part 2 Welding, Settings and Electrode Types We are still dealing with arc welding on our broken bushog in this series. Our welder of choice for this project will be an AC arc welder since it seems to be relatively common on farm sites and will also give us the heat we need for a good penetrating weld. We've also amassed our protective gear and decided on our location for work. The onlookers have been chased away for their own protection. So what else do we need to know before we start welding? I suppose we should probably take a look at the electrodes, or welding rods, and see what they are all about. The welding rod is where the action takes place. This is where the heat is concentrated, the puddle of metal is manipulated, and the repairing weld is created. Professional welders consider many factors when picking out a rod for a job. The types of material being welded play a large part in this choosing process. Is the metal a mild, low alloy, or nickel steel? Does it have other melted components like chromium, manganese, or vanadium in it? Is it aluminum, copper mix bronze or lead? There are almost too many types of metals to choose from, each using a different rod to ensure proper metal bonding. So for our bushog repair we'll just settle for a mild steel type of rod. Next we have to have a basic understanding of what all those gazillion numbers imprinted on the rod mean. Most rods that one runs across at the farm supply store will be labeled something like this: E 6011 or, perhaps, E 7020. The 'E' means that it is an electrode suitable for arc welding. The following two numbers indicate the tensile strength of the material in the rod when the weld is stress relieved. '60' stands for 60,000 psi, '70' for 70,000 psi, etc. The next number, a one, two, or three, indicate the position of the joint the electrode is designed to weld. For example, an electrode numbered XX1X will weld in all positions. A XX2X will weld butt and fillet joints in the flat or horizontal position. XX3X is recommended for flat position welds only. The last number is an indicator of the power supply, type of covering, type of arc penetration and presence of iron powder. Once again, since thoroughly understanding all these numbers, metal types, and flux compounds won't get our bushog repaired we'll simply settle for some general guidelines. 1. A 60XX rod will be easy to find at our supplier and will work great for our mild steel application. 2. Since cracks rarely stick to flat surfaces we will opt for a multipositioning rod, XX1X 3. The fourth number, XXX1 will provide us with an arc stabilizer which will give us AC capabilities. 4. Our rod selection should be E 6011 for our bushog repair. Now that we've selected our welder, our safety equipment, and rod lets get an idea of the current level to use. The thickness of the metal to be welded and the diameter of the corresponding rod will pretty much determine the amperage setting. Pick out a rod that is about the same size as the metal. An 1/8 inch rod will have a setting between 30 and 80 amps. The higher the setting the more heat generated; consequently, the weld will have to be faster or the metal will burn out; there may also be more splatter to contend with. The lower the setting the more sluggish the arc will be, there will be poorer weld penetration, and the arc may flame out more often. Experimenting on a piece of scrap metal will help determine the setting you are most comfortable with. If you are using a 3/16 inch rod the settings can be between 100 amps and 200 amps. Again, it is determined by the welders skill and comfort in performing his work. Metal preparation is the key to making a good weld. The surfaces must be clean of rust, dirt, grease and grime. Grabbing that wire brush and scrubbing away like brushing your teeth will go a long way to cleaning the area to be worked on. If there is a stress crack which is being welded take a hand grinder and grind a 'V' the length of the crack in order for the weld to penetrate both sides of the break. After each pass chip off the slag and debris and wire brush the area before another weld is made. Cracked areas hiding under splatter, rusty metal flakes and/or layered metallic garbage should have the debris ground off so the weld will be made against the parent metal or the most basic of structure. If there are multi levels of paint on the piece then take a grinder and work out the paint so the arc will strike easier and so the weld will have better integrity. One last note, when the final weld has been cooled and the slag and debris cleaned off of it inspect it carefully to make sure it did what you wanted it to. Look for undercutting of the parent metal as this can form a weak spot in the repair. Make sure you followed the crack and didn't wander off to the side in the excitement of keeping a good arc and metallic bead. Check to make sure there is ample bead on the repair and that any repair plates have good penetration on their edges. Finally drop a good coat of primer and paint on the repair to protect the bare metal from the elements. Welded repairs seem to rust quicker than any other type of exposed metallic areas. Besides a good coat of paint will look good and make the repair look complete. Welding Basics, Part 3 In our series on welding we have taken a brief look at AC and DC arc welding along with basic techniques and safety equipment required for safe usage. Since our premise is to cover welding types that might best be used on a farm environment we have kept our overview purposefully simple and general. The second type of welding that this observer finds quite useful in working with older equipment on the farm is that of oxy-acetylene welding. Commonly called gas welding it can readily be used for repairing lighter gauge steel as found on body parts or exhaust systems along with difficult to repair delicate parts like dash parts and special light weight holding devices. Let’s take a brief overview of oxy units and their usefulness on the farm. The term ‘gas welding’ is not really limited to the use of oxygen and acetylene. By definition it is the burning of a gas flame, such as natural gas, LP, hydrogen or acetylene, in the presence of an oxygen source either from natural air, compressed air or pressurized pure oxygen. For our purposes it is most convenient to focus on acetylene gas and pressurized pure oxygen as our gas source since it gives us the hottest flame capable of melting the common metals encountered on the farm. Our term ‘gas welding’, therefore, is the art of joining various metals together by melting and fusing their adjoining surfaces by using an intense, concentrated gas flame as the heating medium. Let’s take a quick look now at the equipment involved with an oxy-acetylene setup. The most obvious items noticed are the tanks that store the two gases. It should always be remembered that the pressurized oxygen and acetylene tanks are to be respected and taken care of. They can be quite lethal if dropped or misused. The acetylene tank is usually the smaller and chunkier of the two tanks. Acetylene gas is highly unstable at pressures over 15 psi so it is stored in an unusual manner. The stubby tank contains an inert substance like fullers earth or lime silica, which absorbs acetone. The acetone absorbs the acetylene and kind of keeps it in suspension preventing accumulating pockets of high-pressure gas thus stabilizing the explosive tendencies of the gas. Be careful not to lay the tanks on their side as this will permit some of the acetone to enter the valves, lines, and gauges and contaminate the system. A purplish flame color at the torch is an indication of this contamination. Also note that the shutoff valve on the acetylene tanks have left handed threads so the appropriate regulator and corresponding hardware can be properly installed. It is recommended that this valve only be opened an average of one half turn when in use so it can be quickly turned off in case of emergency. The other cylinder in the pair is the oxygen tank. This can almost be characterized as a loaded bomb. The gas in a fully charged cylinder has more than one ton of pressure for every square inch of surface area. The gas is an oxidizer that supports common combustion to the extreme and will make typical items burn with an unbelievable violence and intensity. It should be respected as such and measures should be taken to ensure a secure storage and usage environment. When not in use with the corresponding regulator the oxygen cylinder, as with the acetylene tank, has a heavy-duty screw on cap that protects the valve. It should always be used. In addition the cylinders should always remain securely fastened to a wall or similar structure to keep them from tipping over. Since the various gases are stored at considerably higher pressures than are used in the welding process a pressure regulating mechanism must be provided. Pressure regulators that fasten to the respective cylinders of gas provide this function. They reduce the cylinder pressure to a working pressure and also maintain a constant gas pressure at the torch even though the cylinder pressure may vary. Most regulators are a two-gauge unit, the high pressure or primary gauge reflecting the cylinder pressure, the low pressure or secondary gauge showing the delivery pressure to the torch hose. Once again, the oxygen fittings are right hand thread, the acetylene are left hand threads. Take care fastening the respective gauges to their cylinders and hoses. Don’t over tighten and make sure to use the correct wrench to avoid curling the brass nuts and fittings. Check to make sure the regulator-adjusting valve is screwed out all the way to prevent premature charging of the secondary circuit. Charge the gauges by slowly cracking the cylinder valves open to prevent pinging of the gauge needles or melting of the seats due to sudden heat compression in the gauge. Never use any type of oil or grease in conjunction with oxy-acetylene fittings or related components. Once again, make sure all tanks are securely fastened to a wall or supporting structure to prevent them from tipping over. Keep in mind that acetylene gas is highly unstable at pressures over 15 psi. Make sure the secondary gauge measuring the acetylene gas going to the torch hosing never goes over that pressure. The hoses delivering the gases from the tanks to the torch should be of a regular welding type. The rubber is designed not to break down by the respective gases and already has the correct fittings pre-fitted on the ends. Take care not to kink the hose or step on it as it stretches across the work area. Also try to protect it from melted metal globules that are produced in the welding process. Once again the fittings are either left or right hand threads matching the corresponding gas used. The hose fittings screw into the respective left or right hand receptacles of the gas torch. The torch is where the gases are mixed and delivered to the torch tip where they are ignited and used for welding purposes. The gases are directed into the torch base and through respective shut off valves. These valves serve two purposes: one for shutting off and on the gas stream the other for throttling the gas flow to give the flame the correct characteristics for proper burning. From the valves the gases flow into the main body of the torch and into the mixing chamber. Then on through the torch barrel to the tip where it is expelled through a drilled hole called the orifice. The orifice size depends on the type, and thickness of metal being welded along with the rod diameter and heat/pressure requirements. Keeping the orifice cleaned and free of welding debris will assure a clean and properly formed flame. As with any welding proper safety gear should be mentioned before the welding procedure takes place. Make sure and wear the correct protective eyewear. The flame and puddle of molten metal emits both ultraviolet and infrared rays that may cause eye injury if viewed at close distance. The goggles also protect the eyes from flying sparks and the occasion popping of overheated metal. Generally speaking the thicker the metal to be welded and the more heat produced by the torch requires a darker shade for eye protection. A number of 4-5 is a good all around shading for the casual gas welder. Protective clothing consists of heavy leather gloves with a gauntlet covering the wrists, a non-flammable shirt or jacket and flame resistant trousers without cuffs. Good heavy leather shoes with thick soles will award a little more time if one accidentally steps on a hot piece of metal. Also be aware to not wear accessories like pens and other pocket items on your person when welding. A carefully misplaced spark in an oxygen rich environment might cause a quick burn scenario that could create a potential problem. Acquire and use a flint and steel lighter for igniting the torch. The steel cup tends to trap a small amount of gas that quickly and safely ignites when sparked. We’ve taken some time to give a brief overview of the oxy-acetylene welding unit and offered some safety advice. In the next part of this series we will look into the welding process and finish up with a few tips on using the cutting torch. Welding Basics, Part 4 Oxy-Acetylene Welding - Part Two Our ongoing series is discussing some basics in barnyard welding. The previous article gave some introductory material on the equipment and safety factors when working with an oxyacetylene unit. This portion will try to deal with the gas welding procedure and what we can use it for. We've been working slowly but surely on our bushog repair over the past several months. Let's pretend for a moment that our natural talent for stick welding has surpassed all our dreams and our heavy framing and reinforcement is complete. Now we need to weld on the sheetmetal so we can wrap this thing up and paint it. But to our surprise the arc tends to melt the sheetmetal faster than the metal framework. The difference in metal thickness makes the thinner metal blow away before a puddle can be formed. Here is a great example of how gas welding can come in handy. Let's take a quick review before we start. Our oxygen and acetylene tank are secured to the wall, stand, or cart with a chain. The regulators are in the off position or are unscrewed all the way so no pressure is present on the diaphragm. The hoses are safely wound away from the weld-site. We have our gloves, goggles, leather wear, and safety shoes on and our uncoated steel rod is lying to the side, easily accessible within our reach. The repair has been wirebrushed and cleaned of debris and is ready to weld. When gas welding with thin tin like on our bushog we want to keep the pressures on the regulators quite low so we don't make a blowing flame. We are also using a smaller orifice on the torch to help keep the heat level low. In general the thin metal we are welding will require a rod about the same thickness. If the sheet metal is 1/8 inch in thickness, then we need a 1/8th uncoated rod. The torch orifice size is equated to a numbered drill size, in this case a size 54 -57 tip drill size. The pressures on the regs are low: 5 psi for the oxygen and 5 psi for the acetylene. Remember these are pressures for gas welding with a single orifice torch. Pressures for the cutting torch are different and are not for this type of repair. Remember to open the gas tank cylinders slowly to prevent regulator damage and then screw down the diaphragm adjusters to the appropriate pressure settings. It can be helpful to open the corresponding torch valve at the same time to bleed the gas in the line off and to ensure the correct gauge setting. Now we are ready to light up. Open the acetylene torch valve no more than 1/16 of a turn. Cup the flint lighter over the tip to collect a little gas and ignite. Next, turn the acetylene torch valve on slowly until the acetylene flame becomes turbulent a distance of 3/4 inch to one inch away from the orifice. Note that at this distance the flame will stop smoking. When proper turbulence is recognized open the oxygen valve a little bit. Note the color change in the flame and the slow development of an double inner cone within the acetylene flame. As oxygen is increased the larger middle flame will merge with the inner greenish hued cone. When there is only one lightish green/blue cone established then the flame is called a neutral flame. If the secondary or middle flame is still visible then the flame is called a carburizing flame; a cooler flame with too much acetylene is being consumed. If the inner cone is established and then additional oxygen is added it becomes an oxidizing flame. This is also characterized by a hissing sound to the torch and more of a bluish tinge to the flame. Too much oxygen will burn or oxidize the metal being welded. The neutral flame has a soft purring sound to the torch, has a well defined inner cone with the greenish/blue tinge, and is the hottest part of the flame produced. This is the flame we are looking for. Next step is to heat the metal we are going to weld. In the case of our bushog we want to preheat the thickest metal first. Hold the torch at a 30 to 45 degree angle to the work. The flame spreads over the work in the direction in which the weld is progressing and acts as preheater to the material. Rotate the torch tip in a circular motion for even heating and puddle control; hold the inner cone just above the developing molten puddle of metal. This motion should be contained within the parameters of the created molten puddle and not stray outside the welding area. If the puddle starts to sag or burn through then adjust the distance of the flame to the weld by increasing the angle of the flame rather than by pulling the flame away from the puddle. The molten puddle that you create with the flame is what will make the weld between the metals. When working with the different thickness’ of metal it is necessary to form the puddle on the thickest portion of steel and then float the puddle onto the thinner steel so as to not burn through. Adding extra metal to the puddle with a rod may or may not be necessary. If the parent steel is thick enough then the puddle may flow easily to the thinner steel and form a great weld. If additional metal is needed then the rod may be added. Move the rod towards the flame so it is preheated then place the rod end into the puddle as more metal is required. The flame will melt the rod accordingly. Try to avoid a dripping rod as this only creates a weaker weld. As with most things it takes some practice, trial and error. Take some scrap pieces to practice on before doing a finished job which will show your skill; or lack thereof. Here are a couple of tips to keep in mind as you weld. The appearance of the puddle will be a good indicator as to your progress. A good puddle will have a smooth, glossy appearance. The edge away from the torch will have a small bright incandescent spot which will move actively around the edge of the puddle. If this spot is oversize the flame is not neutral. If there are weld bubbles and excessive sparks then there is either a poorly adjusted flame or a poor quality/dirty metal/rod that you are working with. If the torch pops and spits then try to increase the pressures in the regulators just a little bit. The gases are preigniting and may be corrected by a somewhat higher pressure from both tanks. The tip also may become overheated by operating it too close to the molten puddle; try extending that distance. Another possibility of torch popping is that the tip may have some carbon deposits or hot metal particles in the orifice. Using a properly sized tip cleaner will open the passage back up. Avoid submerging the inner cone into the molten metal as this can create a flashback condition where the gas burns back into the regulator. All in all the more time spent practicing with the puddle the better the weld seams that will be produced. Take your time and slowly move the puddle forward along the metal seams making sure the circular motion of the torch is consistent. Heat control by this method ensures that the puddle will not grow out of hand or that a burn through will result. With a little practice one will find that this type of welding is real handy when working with thinner metals because it offers quite a bit of creative control in the weld. In the last installment of this series we will give some tips and instruction on using a cutting torch. Welding Basics, Part 5 Oxy-Acetylene Torches My favorite tool in my arsenal of welding stuff is the cutting torch. It seems that whenever I get into a difficult situation the cutting torch comes running to the rescue. The versatility of this tool is amazing. It can be used for making tools, freeing stuck nuts, heating and bending things to fit, not to mention the regular cutting of steel parts for fabricating and repairing things. The cutting torch is indeed a universal tool in the field of welding. Put simply the cutting torch is like a whole bunch of regular gas torches all bundled into one. In addition there is a single, large orifice in the center of the tip that delivers pure oxygen to the weld when actuated with the cutting lever. This oxygen, under the proper circumstances, will immediately oxidize the pre-heated metal and, put simply, make it disappear. Let's take a quick look at how this really works. As mentioned the cutting torch assembly is rather similar to the oxy-acetylene torch. In fact many torches have interchangeable ends, which makes the changeover from a welding torch to a cutting torch a quick and easy swap. For our purposes the torch base, hoses, regulator gauges, valves and tanks are the same for welding and cutting. The safety procedures and equipment are also the same and should be thoroughly checked before using the unit. The main difference between the torches is that the cutting torch attachment has an additional oxygen pre-heat valve, an oxygen-cutting valve with cutting lever, and a different type of configuration in the gas delivery and flame expulsion, and a multi-ported tip. To put it all in simple terms the acetylene gas flow is still controlled in the same location as the welding torch. But the oxygen control has moved from the lower valve to a new position up farther onto the body of the cutting torch assembly. When using the torch this lower oxygen valve is opened all the way while the 'new' upper valve is used to control the throttling or neutral flame control setting required for operation. The oxygen- cutting lever, now under full pressure through the lower valve, is used to deliver a blast of pure oxygen at the appropriate time to the metal we are cutting. The settings, as with regular gas welding, are determined by the thickness of the metal that you want to cut. A typical example for cutting 3/8 inch to 3/4 inch steel would be the following: a preheat orifice drill size of 58, a cutting orifice drill size of 62, oxygen pressure of 30-40 psi, acetylene around 5 psi. The multi-preheat flames, as with the single welding flame, need to be ignited with a sparkler and set to a neutral flame using the same techniques described in our previous series. Give visual consideration to optimizing the neutral flame as an oxidizing flame will be harder to work with. The real key to cutting metal with a torch is to always heat the working metal to cherry red. If the metal is too cool it won't cut. If it is too hot, as in white hot, it splatters, undercuts, and reduces the quality of the cut. Laying the base metal on a pair of vee blocks or steel spacers will help facilitate the cutting process. Preheat the metal edge to a dull cherry red using the tip of the multi-flame cones for maximum heat. A tight circular pattern over the starting area will even out the preheating. When a small cherry red dot appears apply the oxygen cutting valve lever. The metal will blow away like a stream of butter as the oxygen oxidizes and melts the metal in contact with the high pressure stream of gas. While holding a vertical attack angle slowly follow the melt line with the torch until the cut is complete. Prescribing the cut line with welders chalk makes following the cut line a lot easier. As with anything once the basics are understood practice makes the best teacher. With time (and a good piece of chalk to mark your cutting lines) further skills can be realized. One of these skills is being able to fabricate parts for repairs. Many times, such as our bushog, a piece of plate steel has to be cut and fit over a cracked section or hole in order to make the repair. The cutting torch is ideal for making these custom fabrications. By chalking the lines of the desired filler piece on a section of steel the cutting torch can make exact repair plates of virtually any type and size. With additional time and skill one can also learn to make angle cuts with the torch to create a ‘pre-cut’ chamfer in the plate for stronger welds. After the cuts are made the magic of a hand grinder can make the plate look like a factory part. One great feature of the torch is that it can be used to ‘make stuff fit’. By heating parts to cherry red they can be bent and tweaked to various angles. Support rods or plate reinforcing can be bent to mate perfectly to matching parts. Rebar can be bent to perfect and tight 90-degree angles for support cages. Plates that have to be placed over obstructions can be heated and tweaked to have bumps, ridges, or chamfers in them. When heated to the right temperatures it is amazing to see just how pliable steel becomes. Steel tubing can be filled with sand, heated, and then gradually bent to strange angles. Done slowly and with care the pipe integrity will not be sacrificed. Sometimes in the shop one can run across a huge nut or bolt that requires an expensive wrench to remove. A piece of scrap steel, some carefully scribed chalk lines, and a steady torch hand can create a make-shift wrench that will comfortably work. Of course you will probably have to do some grinder touch up work on your new tool addition before it will fit close enough to use. In addition the ‘working end’ can be roasted to cherry red and quenched in some water to obtain some tempered features. Frequently one will run across a nut that won't budge with a well-fitted wrench. Even a pipe extension, commonly called a cheater bar, won’t crack it free. By taking our torch and heating the nut to our famous cherry red it will usually break free with only the effort of our wrench. Granted you might have to install a larger torch tip to release the amount of heat needed to toast that much steel. But it is amazing to see what a little heat can do on stubborn nuts. The key is to heat only the nut cherry red so it expands over the stud. On most stuck nuts there is a layer of rust between the bolt and nut that has caused the seizure. This layer can act as an insulator and retard the transfer of heat to the stud. If the nut is heated too long then the stud will also receive too much heat, start to get red, and then probably snap off when torque is applied. Focus the heat only on the nut and, when it releases and starts to turn, get it off quickly. If it seizes up again reheat it back to red and try again. Sometimes it is a stubborn bolt that is stuck in a component. Try heating the surrounding metal and then backing the bolt out with a wrench or vise grips. Be especially careful if it is a cast iron component. It is recommended that drilling and using an easy-out first be tried as cast iron can do strange things if too much heat is applied. In a case of a broken stud in an engine block sometimes the stud can be heated cherry red, then quenched quickly with some ice wrapped in a rag. The sudden temperature change can sometimes break the rust layer free and give some space to rotation of the stud. If all else fails a very small torch tip, a steady hand, and nerves of steel can sometimes be used to cut a problem stud out of a cast component. This last gasp tactic is best reserved for the experienced. All in all the cutting torch is one of the most universal and versatile tools in the arsenal of the home repairman. Make sure and keep it clean and tidy so it will be ready to serve when most needed. ---------------------------------------------------------------------------------------- Welding Electrodes 6011 Welding Electrodes An all-purpose stick electrode for use in all positions on carbon and galvanized steel. 60,000 PSI tensile strength. Deep penetrating, ideal for welding through light to medium amounts of dirty, rusty or painted materials. Runs on AC or DCEP (reverse) polarity. 6013 Welding Electrodes A light to medium penetrating all-purpose stick electrode for use in all positions, on carbon steel. Runs on AC or DCEP (reverse) polarity or DCEN (straight) polarity. 60,000 PSI tensile strength. Good for general, all-purpose applications and joints with poor fit-up. 7014 Welding Electrodes For high-deposition requirements, this stick electrode is ideal for applications requiring light penetration and faster travel speeds. It runs in all positions on AC or DCEN (straight) or DCEP (reverse) polarity. 70,000 PSI tensile strength. 7018 Welding Electrodes A low-hydrogen electrode for use in all positions on low, medium and high-carbon steels. 70,000 PSI tensile strength. Ideal for out-of-position welding and tacking. Runs on AC or DCEP (reverse) polarity. Not recommended for low-voltage AC welders. 7018 AC Welding Electrodes Same as above, but specially formulated to operate with small 208/230 volt AC welders. -------------------------------------------------------------------------------------------------------------------- Specialty Electrodes Stainless Steel Electrodes, 308L For 308 and 304 stainless base metal. Smooth, tough welds with the strength, corrosion and crack resistance needed for welding stainless steel in all positions. Easy slag removal. Runs on AC or DCEP (reverse) polarity. Stainless 312 Plus Electrodes For hard-to-weld or dissimilar metals, stainless, high-carbon, cast, and high-nickel steels. All-position, AC/DC (electrode positive), easy strike and re-strike, high moisture resistance, self-detaching slag. Aluminum Electrodes, 4043 Aluminum welding for flat, horizontal and vertical applications. DC only. Nickel 55 Electrodes For repair in all positions of materials with 55%-nickel cast iron. This electrode produces welds with higher strengths and ductility than the straight nickel electrodes. Deposits are machinable, but harder and more resistant to cracks and abrasion than high-nickel welds. Nickel 99 Electrodes This high-nickel-content electrode is good for castings of light to medium weight. Welds are easily produced in all positions and the deposits are readily machined. Hard Surfacing Electrodes, Overlay A high-chromium-manganese-alloy electrode is used for buildup and overlay. Used for austenitic as well as carbon and low-alloy steel. Excellent impact resistance, good abrasion resistance and improved corrosion resistance. Hard Surfacing Electrodes, Build Up This high-chromium-carbide-alloy steel electrode is used for overlay on carbon, low-alloy or austenitic manganese metals.Excellent abrasion resistance good impact and improved corrosion resistance. Cutting/Chamfering Electrodes For cutting, beveling, or gouging of all metals and removal of weld joint overlays or other unwanted materials. All-position, AC/DC (electrode positive) Nomacast Electrodes For various grades of cast iron, this electrode provides an excellent, non-machinable base pass for subsequent nickel alloy repairs on contaminated cast iron. AC/DC (electrode positive preferred). Flux Coated Brazing Rods Low-fuming-type brazing alloy for general purpose brazing of steel, cast iron, nickel, some nickel alloys, copper and some copper alloys. Use oxyacetylene or other fuels suitable for brazing.