My Opinion on the advantages and
disadvantages of GMAW, SMAW, and GTAW
This was posted on the AWS BBS
SMAW-
Shielded Metal Arc Welding
Advantages
Lower equipment cost than GTAW and GMAW. (No bottle, gas hose, flowmeter, and
tig rig/Wire feeder needed.
Quick Change from one material to another.
The process lend itself to welding in confined spaces and various positions with
few problems.
Deposition Rates faster than GTAW Manual
Easy to move from one location to another
Some special electrodes are made for cutting/gouging
Requires no outside shielding gas and can be used outdoors in light to medium
wind.
Disadvantages
Low deposition rate compared to GMAW/FCAW
Filler metal cost per weld can be greater due to a low deposition efficiency
that can vary greatly with stub length.
Production factor is typically lower (Unless welding on various materials) due
to rod changes and chipping slag.
Needs more hand eye coordination than GMAW
GMAW-Gas Metal
Arc Welding
Advantages
High deposition efficiency when used in certain transfer modes.
No Slag to chip
The process can be used on thin materials with relative ease if properly set.
Low Hydrogen
High production factor since no slag is required to be removed and uses a
continuous electrode.
With the parameters properly set for the application, anyone can weld after a
very short amount of practice.
Disadvantages
Requires a Wire Feeder which is difficult to move and can sometimes be a
maintanence/repair burden.
Needs Shielding Gas
No slag system so out of position welds are sometimes more difficult.
Increased chance of lack of fusion if parameters and welding technique is not
controlled.
The gun is difficult to get into tight places.
Is not suitable for windy conditions.
GTAW- Gas Tungsten Arc Welding
Advantages
No slag (Unless using fluzed rods), No Spatter
The low energy input allows the welder to control the puddle with ease compared
to other processes. (Only because the amount of molten metal is low comapared to
other processes IMO)
Autogenous welds can be made (No Filler metal required)
Because the welder can vary the amount of filler metal and can also manipulate
the torch easily, the process is good for welding root passes in joints
accessable from one side only.
Can be used on a very wide range of base metals relatively easily.
Wide range of thicknesses
All that is required is a stick welder and the proper gas to weld Alum, SS,
CuNI,Carbon Steel etc.
Disadvantages
V E R Y low deposition rate
Requires shielding gas
The welder must manipulate both the torch and filler metal. (A little harder in
a mirror sometimes or restiricted access locations)
Requires more manual dexterity than GMAW/FCAW.
Requires tungsten electrode.
Thought by many to be "better" than everything else but in my opinion
it is just another process.
AND
:) Sometimes leads to "Golden Arm Syndrome" that results in starched
Khaki shirts, red bandannas with $100.00 worth of 316L swagelock fittings
holding it together, tungsten holders fabricated out of various alloys with more
swagelock fittings, the inability to weld on anything that is not round with a
hole in it, and the constant belief that the last job and the next job are
better than the one you are on.
G Austin
