What's the difference between TIG and MIG welding, and for what applications are each best suited?
TIG v. MIG welding
- Thread starter Russ
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Yellow Rose
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TIG - tunsten inert gas - the electrode is tungsten and is not consumed.....the items being welded to each other are fused together by "melting".
MIG - metal inert gas - the electrode is whatever the metal is being welded together and is consumed.
The inert gas with either process is commonly Argon.
MIG - metal inert gas - the electrode is whatever the metal is being welded together and is consumed.
The inert gas with either process is commonly Argon.
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BTW - TIG is usually considered the best way to weld Stainless Steel together. Here is some additional info:
The TIG (Tungsten Inert Gas) welding process (also known as gas tungsten arc welding, GTAW, or HELIARC, a trade name of Linde) generates heat from an electric arc maintained between a non consumable tungsten electrode and the part being welded. This process was developed for the aircraft industry back in the early '40s. TIG may be used without the addition of a filler metal or a separate wire filler metal can be added into the puddle when additional material is required, much like the process in oxy-acetylene welding. The puddle, the tungsten electrode and the filler rod are protected from atmosphere by a shield of inert gas to prevent rapid oxidation of the weld and surrounding metal. Argon is the most widely utilized gas. Because the gas shield does not produce the slag that normally is created by flux, the danger of slag inclusion in the weld metal is eliminated. Also, due to the slow speed of the TIG process, gases and other impurities escape to the surface of the puddle before solidification occurs, eliminating pockets called "Porosity" common in weld processes that employ gas shielding but have greater travel speeds than the TIG process. TIG also produces a welding heat is that is confined between the weld and base metal at the point of fusion and produces a narrow heat affected zone. This reduces stress, cracking and distortion in the finished weld. Spatter is not produced by this process, leaving the weld and surrounding metal clean. Because of the lack of spatter and flux smoke, the TIG process allows the operator a clear view of the weld puddle. The torch body in most cases is small enough that the operator can hold it in the same manner as he would hold a pencil allowing easier manipulation. The power source is constant current, either AC, DC, or combination AC/DC. Type of metal determines which type is used. DC (direct current) is most normally used for TIG welding of stainless steels and mild and low alloy steels. AC (Alternating current) is used for TIG welding of aluminum. Surface oxidation is automatically removed by the action of the arc each time the electrode becomes positive, (60 times per. second). Because AC crosses over the zero volt point 120 times per second (once going positive and once going negative each cycle), the arc shuts off 120 times per second. To keep the arc going when using AC, a high frequency "arc stabilizer" is used. The high frequency also allows the start of an arc in DC mode without having to "strike" an arc, thereby reducing the possibility of tungsten contamination. If the electrode accidentally touches the weld pool, it becomes contaminated and must be cleaned immediately to prevent weld contamination. TIG requires an extremely clean surface to weld successfully and is a fairly slow operation. On the plus side, TIG produces high quality work and does not generate slag or spatter. The welder can adjust the heat input while welding by using foot or hand amperage controls.
MIG (Metal Inert Gas), also referred to as wire feed welding, utilizes a consumable arc. The process generates heat from an electric arc maintained between a consumable wire feed electrode and the part being welded. This process produces spatter making it difficult for the operator to see the weld and causing damage to nearby surfaces and objects from the hot particles thrown off. Flux cored "gasless" welders produce smoke from the flux, and pose a cleanup problem. Because of the higher welding speeds of the MIG process, the chance of producing porosity is higher. A common mistake with novice welders utilizing the MIG process is the possibility of producing a good looking weld with little penetration. A MIG can produce an arc into the puddle, allowing one to create a nice looking weld while the base metal underneath is not being properly melted. This cannot be detected before failure without either destructive or non-destructive testing. In the TIG process, the base metal is melted to produce a puddle before any filler is introduced into the weld. This allows the operator to see the penetration during the welding process. Another drawback in MIG welding in restoration of automobiles is the workability of the weld. The wire used in MIG cools harder than in TIG welding, making it harder to hammer and dolly the weld afterwards. Because MIG welding uses a constant fed wire to produce the arc, some buildup of material usually occurs that has to be ground off. This also generates heat in the panel that can cause warpage. With TIG, filler is only added when needed, and the thickness of the filler can be changed by picking up a different size rod. This reduces post weld finishing. While TIG welding requires greater skill, the results are far better than other welding methods. Welders of both types are available from many sources, such as Eastwood, Daytona Mig, and Professional sources such as Miller Electric. A source that I have found to be particularly helpful and has excellent prices is RRAM Sales. If you are looking for a welder, I recommend staying away from Flux cored units. They are messy and many do not have the power required to do most welding you will get into. Small 110 volt welders are available that will do a good job with practice, but go with gas for MIG (MIG by definition is metal INERT GAS, not flux) Flux cored units are advertised as "wire feed", Don't assume that they are MIG welders. If you are looking for a TIG, there are also several nice small units available, but consider it only if it has "high frequency" and AC if you don't want to mess with striking an arc and there is a remote possibility that you may want to weld Aluminum someday.
The TIG (Tungsten Inert Gas) welding process (also known as gas tungsten arc welding, GTAW, or HELIARC, a trade name of Linde) generates heat from an electric arc maintained between a non consumable tungsten electrode and the part being welded. This process was developed for the aircraft industry back in the early '40s. TIG may be used without the addition of a filler metal or a separate wire filler metal can be added into the puddle when additional material is required, much like the process in oxy-acetylene welding. The puddle, the tungsten electrode and the filler rod are protected from atmosphere by a shield of inert gas to prevent rapid oxidation of the weld and surrounding metal. Argon is the most widely utilized gas. Because the gas shield does not produce the slag that normally is created by flux, the danger of slag inclusion in the weld metal is eliminated. Also, due to the slow speed of the TIG process, gases and other impurities escape to the surface of the puddle before solidification occurs, eliminating pockets called "Porosity" common in weld processes that employ gas shielding but have greater travel speeds than the TIG process. TIG also produces a welding heat is that is confined between the weld and base metal at the point of fusion and produces a narrow heat affected zone. This reduces stress, cracking and distortion in the finished weld. Spatter is not produced by this process, leaving the weld and surrounding metal clean. Because of the lack of spatter and flux smoke, the TIG process allows the operator a clear view of the weld puddle. The torch body in most cases is small enough that the operator can hold it in the same manner as he would hold a pencil allowing easier manipulation. The power source is constant current, either AC, DC, or combination AC/DC. Type of metal determines which type is used. DC (direct current) is most normally used for TIG welding of stainless steels and mild and low alloy steels. AC (Alternating current) is used for TIG welding of aluminum. Surface oxidation is automatically removed by the action of the arc each time the electrode becomes positive, (60 times per. second). Because AC crosses over the zero volt point 120 times per second (once going positive and once going negative each cycle), the arc shuts off 120 times per second. To keep the arc going when using AC, a high frequency "arc stabilizer" is used. The high frequency also allows the start of an arc in DC mode without having to "strike" an arc, thereby reducing the possibility of tungsten contamination. If the electrode accidentally touches the weld pool, it becomes contaminated and must be cleaned immediately to prevent weld contamination. TIG requires an extremely clean surface to weld successfully and is a fairly slow operation. On the plus side, TIG produces high quality work and does not generate slag or spatter. The welder can adjust the heat input while welding by using foot or hand amperage controls.
MIG (Metal Inert Gas), also referred to as wire feed welding, utilizes a consumable arc. The process generates heat from an electric arc maintained between a consumable wire feed electrode and the part being welded. This process produces spatter making it difficult for the operator to see the weld and causing damage to nearby surfaces and objects from the hot particles thrown off. Flux cored "gasless" welders produce smoke from the flux, and pose a cleanup problem. Because of the higher welding speeds of the MIG process, the chance of producing porosity is higher. A common mistake with novice welders utilizing the MIG process is the possibility of producing a good looking weld with little penetration. A MIG can produce an arc into the puddle, allowing one to create a nice looking weld while the base metal underneath is not being properly melted. This cannot be detected before failure without either destructive or non-destructive testing. In the TIG process, the base metal is melted to produce a puddle before any filler is introduced into the weld. This allows the operator to see the penetration during the welding process. Another drawback in MIG welding in restoration of automobiles is the workability of the weld. The wire used in MIG cools harder than in TIG welding, making it harder to hammer and dolly the weld afterwards. Because MIG welding uses a constant fed wire to produce the arc, some buildup of material usually occurs that has to be ground off. This also generates heat in the panel that can cause warpage. With TIG, filler is only added when needed, and the thickness of the filler can be changed by picking up a different size rod. This reduces post weld finishing. While TIG welding requires greater skill, the results are far better than other welding methods. Welders of both types are available from many sources, such as Eastwood, Daytona Mig, and Professional sources such as Miller Electric. A source that I have found to be particularly helpful and has excellent prices is RRAM Sales. If you are looking for a welder, I recommend staying away from Flux cored units. They are messy and many do not have the power required to do most welding you will get into. Small 110 volt welders are available that will do a good job with practice, but go with gas for MIG (MIG by definition is metal INERT GAS, not flux) Flux cored units are advertised as "wire feed", Don't assume that they are MIG welders. If you are looking for a TIG, there are also several nice small units available, but consider it only if it has "high frequency" and AC if you don't want to mess with striking an arc and there is a remote possibility that you may want to weld Aluminum someday.
A little sketchy on the details but I think I got it 
Thanks!
Thanks!
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