Rear Panel; Sockets Panel; Mma Welding Theory; Coated Electrode Welding - Inteco Eagle 242 Instrucciones De Uso

3.3 Rear panel

I1: Off/On switch.
Turns on the electric power to the welder.
It has two positions, "O" off, and "I" on.
1: power supply cable.

3.4 Sockets panel

P1: negative power socket.
For connection of earth cable in electrode welding or
torch in TIG.
P2: positive power socket.
For connection of electrode torch in MMA or earth
cable in TIG.

4 MMA WELDING THEORY

4.1 Coated electrode welding

Preparing the edges
To obtain good welding joints it is advisable to work on clean
parts, free from oxidations, rust or other contaminating agents.
Choosing the electrode
The diameter of the electrode to be used depends on the thick-
ness of the material, the position, the type of joint and the type
of preparation of the piece to be welded.
Electrodes with considerable diameter obviously require very
high currents with consequent high heat supply during the wel-
ding.
Type of coating Property
Rutile Ease of use
Acid High melting speed
Basic Mechanical charact.
Fig.4
Fig.5
Use
All positions
Flat
All positions
Choosing the welding current
The range of welding current in relation to the type of electro-
de used is specified by the manufacturer on the electrode con-
tainer.
Striking and maintaining the arc
The electric arc is produced by rubbing the electrode point on
the workpiece connected to the earth cable and, once the arc
has been striken, by rapidly withdrawing the rod to the normal
welding distance.
Generally, to improve the striking of the arc an initial current
increase with respect to the base welding current is very useful
(Hot Start).
Once the arc has been striken, the central part of the electrode
starts melting and is deposited on to the workpiece in the form
of drops.
The external coating of the electrode is consumed and this sup-
plies the protective gas for the welding, the good quality of
which is thus ensured.
To prevent the molten material drops from extinguishing the arc
by short-circuiting the electrode with the weld pool because of
their accidental proximity to each other, a temporary increase of
the welding current until the end of the short-circuit is very use-
ful (Arc Force).
If the electrode sticks to the piece to be welded, it is useful to
minimise the short circuit current (antisticking).
Carrying out the welding
The electrode inclination angle varies depending on the number
of runs; the electrode movement is normally carried out with
oscillations and stops at the sides of the bead, in such a way as to
avoid an excessive accumulation of filler material at the centre.
Removing the slag
The welding through coated electrodes requires the removal of
the slag after each run.
The slag is removed by means of a small hammer or is brushed
away if friable.
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