Welding Resources and Tips

Welding Aluminum

The process of welding aluminum requires less energy than welding other metals which typically makes it an easier metal to weld.  While this may sound good, there can also be some problems when you are required to use welding equipment that was designed to be used on steel.  This is why it is important for the welder to consult their owner’s manual in order to find the proper settings that can be used for welding aluminum. 

MIG Welding Aluminum

Welding aluminum using the MIG welding process has been known to require the welder to perform some post-welding touchups to the weld area in order to create a more presentable finish.  The process of MIG welding requires the use of an electrode of continually fed wire which forms the base of the welds.  This electrode also requires the welder to use a shielding gas composed of an inert gas or mixture of two gases.  When MIG welding is performed on aluminum the results may be a bit messier than when other metals are welded.  MIG welding aluminum tends to be messier because of the need for the welder to use the spray transfer welding method where the welding arc creates a spray of tiny metal beads.  With time and practice any welder can master the spray technique.

TIG Welding Aluminum

TIG welding is a welding process that doesn’t require the welder to perform as much post-welding cleanup work as is required in MIG welding.  The ability to produce welds that require little to no post-welding work makes this the perfect welding process to use when fast and easy welds are required on aluminum.  The process of TIG welding requires the use of a permanent tungsten electrode which is not consumed during the welding process.  The welder will still be required to add any necessary filler metal manually.  These requirements and restrictions make this process the best to use when there isn’t any additional metal being used.  TIG welding aluminum also requires the welder to use an inert gas to shield the arc.

These two welding processes are the most common welding techniques used when aluminum is welded.  Both of these welding methods will require some practice in order to master the different techniques.  It also important that the welder check all of the settings on their welding equipment prior to welding.  This will ensure that they are all properly set to weld aluminum.  Welding aluminum properly requires patience and practice as do all welding techniques; but once the skill is mastered it will be much easier to produce high quality welds on aluminum.

Titanium Welding Tips

The process of welding titanium requires experience and knowledge in the proper welding techniques.  Using the wrong technique when welding titanium has been known to cause weld contamination and defects.  Titanium can be welded much like any other metal, with a few differences that require different welding procedures to be used.  Titanium has a higher melting point and lower ductility than common steel.  Titanium is also more prone to becoming contaminated during the welding process unlike steel and other alloys.

Before welding titanium, it is crucial that the welder ensure that the weld wire and joints are clean.  It is also important that the welder purge the trailing shield, back-up shield and torch to remove any air that may be trapped inside.  Welding titanium requires more attention to cleanliness than other metals; any accumulation of contaminants on the titanium weld area can degrade the properties of the metal.  If the welder should happen to notice any dirt on the weld wire while inspecting their equipment, it can be easily removed using a cleaning solvent which does not contain chlorine.  If any of the other welding components need to be cleaned prior to welding, they can be cleaned using a mild detergent or other mild cleaning solution and thoroughly rinsed with hot water.  Whenever cleaning has been performed using solvents, the process must be followed by brushing using a stainless steel brush.  Steel wool should never be used when cleaning titanium because it affects the corrosion resistance of the metal.

When welding titanium it is important that the welder use an auxiliary inert shielding gas.  The root side of the titanium welds and other areas that will be affected by the welding heat should be shielded until the temperature reaches 800 degrees Fahrenheit or below.  If the weld turns blue in color, the shielding gas was removed too soon.  Titanium is easily affected by the air, dirt, moisture and other metals.  Because titanium is a specialized metal, common welding techniques are not compatible with titanium because of the different reaction of titanium with fluxes and gases.  When welding titanium, it is important that the welding torch be able to be cooled by water and is equipped with gas lenses and ceramic cups.

Welding titanium is a specialized area of welding and should only be attempted by welders who have the necessary knowledge needed to successfully perform welds on titanium.  Welders also must remember that the space where you will be working should be as clean and free of contaminants as possible.  Working in a clean area will ensure that your welds are of high quality and free of contamination.

Learn more... Some Tips for Welding Titanium

Tips for Welding Inconel

Inconel refers to a group of specific nickel-chromium alloys that are used in different welding processes.  Inconel is most commonly used in techniques that require a high heat tolerance.  Using Inconel in your welding processes can be rather difficult because the welds that are created have a tendency to crack.  There are a few alloys of Inconel that were specifically designed for use in welding, and are most commonly welded using tungsten inert gas welding or TIG as it is commonly known.

To achieve the best results when welding using an Inconel alloy you should use Inconel 625 filler metal.  This is typically the easiest Inconel alloy to weld and is effective when two Inconel pieces need to be welded together.  You can also use Inconel 625 to weld other metals that are dissimilar in composition, such as stainless steel.  When using Inconel to weld it is common for the weld pool to be poorly defined.  Inconel fillers tend to leave a skin like film on the surface of the weld pool and is dirty in appearance.  If this occurs during your welding there is no need for alarm, this is a common side effect of using Inconel as part of your welding.  Inconel produces strong welds which are highly resistant to corrosion when they are properly applied.

The most common method used when welding using Inconel is the TIG technique.  This method allows the welder to have more control over the weld than other methods, such as GMAW and SMAW.  It is important for the welder to have better control of the weld due to the difficulty that the alloy can present.  In order to become proficient using TIG and Inconel, a lot of practice time must be put in.  Welding Inconel using TIG is very demanding on the welder and the more practice you have working with the alloy the better you will become. 

You may also want to consider using an automated welding technique when you are required to work with Inconel.  A method such as plasma arc welding uses a more focused welding arc and is easily automated.  You can also use pulsed micro laser welding, which is gaining in popularity among welders when you have to weld using Inconel.  Welding Inconel is a very demanding process and should not be attempted by beginners; it takes time to master the skill of working with Inconel and it is not something that can easily be learned overnight.  But once you have the knowledge and skill, working with Inconel will not be as intimidating.

Tips for Welding Cast Iron

Cast iron is a metal that typically contains a carbon content of between two and four percent which is much larger than that found in many common steels.  Because of the high levels of carbon, cast iron tends to be very brittle and difficult to weld.  Much of the cast iron welding done requires repairs to existing castings instead of creating new castings.

• It is suggested that cooling or heating be used when welding cast iron is required.  The most important factor in welding cast iron is that it be kept out of the 150 – 500 degrees farenheit range.  You should preheat the cast iron, which is preferred and to also use cooling techiques as well.  It is important when welding cast iron that you do not change welding methods in the middle of a weld.
• When preheating the cast iron you should heat the entire castig slowly and evenly in the range of 500 – 1,200 degrees farenheit.  It is crucial to the success of your weld that you do not overheat the metal, most forms of cast iron begin to crack if the temperature reaches 1,400 degrees and above.  In order to minimize stress you should use a low current to perform your weld.
• It is important that you keep the cast iron you are welding cool but not cold.  If the cast iron part you are working on is located on a piece of powered machinery it may be necessary to run it for a short amount of time in order to achieve the correct temperature.  It is important that the casting you are working with never get so hot that are not able to touch it with your bare hand.  Use short welds about one inch long to avoid the cast iron from overheating.
• When welding cast iron you should expect small cracks to form, even when the proper technique is being used.  It may be necessary for you to apply a sealing compound to joints that are required to be watertight.
• To repair any major cracks that may have formed during welding it is recommended that you use studding to repair the cracks.  This involves screwing steel studs into holes that have been pre-drilled and tapped into the surface that is to be welded.  The studs should be between 5 and 6 mm above the surface to work correctly.  Once they have been put into place they are then welded into place.

 

Welding Copper

Copper and copper-nickel alloys are commonly welded using the manual metal arc technique which uses a stick electrode that has been coated with flux.  This is a generally inexpensive welding process, but it requires using a metal inert gas which is faster and a tungsten inert gas that when used will produce strong welds.

You will want to use a 70 – 30 copper-nickel filler when welding alloys that are at least 70 percent copper.  The high nickel content will produce a much stronger weld than other types of filler metals.  In order to measure the strength of the weld that will created, you can use a longitudinal bend test.  This will help you see how the integrity of the weld will hold up once your weld is completed.

Next you will want to thoroughly clean the material that is going to be welded.  This needs to be done in order to remove any contaminants that can cause the weld area to crack.  It is important that all traces of lead, phosphorous and sulfur be removed from the copper prior to welding.  These contaminants can commonly be found in cutting fluids, grease, oils and paints.  Copper-tin-zinc alloys have been proven to contain these elements and should not be used when welding to copper-nickel alloys.

When welding copper-nickel that is less than 3 mm it is suggested that a square butt be used to prepare the weld materials.  If you are going to weld copper-nickel that is larger than 3 mm it is suggested a beveled preparation be used.  If you are going to be working with carbon steel you should make the included angle wider, typically more than seventy degrees.  The weld metal does not become as fluid as that of carbon steels and typically requires more manipulation with the electrode to make it fuse with the side walls of the weld area.

If possible, when welding copper, you should weld down-hand.  This allows for a greater rate of deposit and is a better technique for beginner welders.  If the piece that you are working on is larger than normal, sub-assemblies should be used for down-hand welding instead of welding in a less favorable or more dangerous position.

It is possible to perform flawless welds when working with copper, all you need is practice and finding the best technique that works for you.  Welding copper can be a tricky undertaking, but it can be done when the proper guidelines are followed.

Reference:  http://www.ehow.com/how_2164566_weld-copper.html