Hi! My name is Mac. On behalf of expertvillage.com,
I would like to continue our discussion about stick welding or shielded metal arc welding.
Today we will be discussing the different kinds of welding machines for this process.
They are basically divided into two types of machines, A.C. machines or Alternating
Current welding machines or D.C. machines, Direct Current machines. Let us talk about
the A.C. machines first. The alternating current machines are usually cheaper. They are very
durable. They have been around for a very long time. You find them an awful lot on farms
and in shops where they do miscellaneous ironwork. The alternating current machines work best
on welding rods like 6013 and 7014. There is even an A.C. version in 7018 that works
very well on alternating current machines. Their duty cycle is something that we should
discuss. All of these stick welding machines have what is called a duty cycle. The duty
cycle refers to the amount of time that you can actually weld in every 10 minutes of time.
A 20% duty cycle means that you can weld at maximum amperage the machine is capable of.
In a 10 minutes time frame, you can weld for two minutes. The other eight minutes of time
you have to allow the machine to cool off. So it is importance to keep your eyes on the
amount of time that you are actually welding in a 10 minute time frame. D.C. welding machines
have the same problem. They require you to keep yours eyes on the welding duty cycle
so that you don’t over heat machine and burn out the transformer. Direct current machines
are as it says a direct current, D.C.. You have two different polarities. Direct current
electrode positive and direct current electrode negative. Electrode negative machines can
sometimes be used for TIG welding on carbon steel and stainless steel. Regardless of the
polarity that you use, these machines are very acceptable for doing all position stick
work, they are widely used in construction and they have several diesel and gasoline
engine driven varieties of D.C. stick welding machine. They do an excellent job and they
are very durable and give you a wider range of options than A.C. electrode machines.