A short description of the most popular welding processesand the top 10 beginner mistakes to avoid.
Welding is a complex subject, and this article is far from being
comprehensiveon any aspect of it. However, one thing that it attempts
to cover is a fewabsolutely necessary requirements and a number of
basic beginner mistakes thatone can easily avoid. As a quick
introduction, the most frequently used and easiest-accessible welding
processes are arc welding/gas welding (including tig welding and mig
welding).
Arc welding describes welding processes that use a welding power
supply to create an electric arc between an electrode and the base
material to melt the metals
at the welding point. They can use either direct (DC) or alternating
(AC) current, and consumable or non-consumable electrodes. The welding
region is sometimes protected by a kind of inert or semi-inert gas,
known as a shielding gas, and/or filler material. Arc welding is widely
used because of its low capital and running costs. MIG (Metal Inert
Gas) and TIG (gas tungsten arc) welding are kinds of gas metal arc
welding.
During MIG and TIG welding, continuous and consumable wire
electrodes and a shielding gas are fed through a welding gun. Constant
voltage, direct current power source are usually used with MIG and TIG
welding, but alternating currentsources can also be used. Originally
used for welding aluminiums, gas metalarc welding was also soon applied
to steels because it allowed to reducewelding time substantially. Some
advantages of MIG welding are that it iseasier to learn, longer welds
can be made without the need to stop and restart,and little post weld
cleaning is necessary. The downsides are an oxidized welddeposit,
unstable arc, and weld porosity. Advantages of TIG welding arethat it
allows welds of higher quality, with or without filling metal,
goodcontrol of heat, and low distortion. Some of the issues with TIG
welding area somewhat erratic (wandering) arc, a high electrode
consumption, and a certainporosity of the weld. Some of the most basic
and frequent mistakes in (mainly MIG, since it is themost relevant for
most readers) welding, from our experience and afterextensive research,
are the following:
1) Not cleaning the parts and weld surfaces properly. As most
experienced welderssay, this is a very frequent beginner mistake. Any
paint, dirt, and similarmaterials can lead to problems and a bad weld
as a result.
2) Using the wrong kind of gas for gas welding. Many people
will opt for cheap gas,which is however sometimes not a good idea.
While simple CO2 is cheap, a mixedgas will often produce better results
while MIG welding.
3) Wrong polarity. This can produce a bad-looking weld bead.
4) Wrong contact tip sizes.
5) Inadequate travel speed, i.e. going too fast or too slow.
6) Insufficient shielding - e.g. not blocking the wind while welding.
7) Welding too cool on a massive piece of material, which results in a lack of fusion.
8) Underbuying, i.e. picking a too small welding machine for the materialthickness required.
9) Not maintaining the wire feeder's wear components, like liners, contact tips, and other parts.
10) Mismatched filler material, i.e. not having the right tensile strength.
For an in-depth description of these and numerous other welding
mistakes,as well as many advanced MIG and TIG welding tips and tricks, checkout http://www.weldingsecretbook.com.
Sergey
holds a M.Sc. degree in CS and is one of the founders and owners of
S-Kaze, Ltd, a company designing and developing innovative
next-generation websites.
