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21A
5
INTRODUCTION TO STUDWELDING
When matched with an appropriate controller and earth cables, the Taylor Studwelding DA8
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A
studwelding pistol is intended for precision stud welding up to 10 mm diameter studs. The pistol is
lightweight, ergonomic and has been designed to operate with a minimum amount of maintenance.
The energy required to carry out the welding operation is derived from an appropriate studwelding
controller.
Taylor Studwelding Systems Ltd controllers are modern, robustly designed and offer maximum reliability
combined with an easy to understand operator interface.
THE PROCESS
The process of drawn arc studwelding is long established and well proven. The basic steps are as follows :
•
A measured amount of weld stud protrusion is set at the welding pistol.
•
Once in position, the pistol lifts the stud away from the work
-
piece, simultaneously striking an arc
between the two.
•
Both the tip of the weld stud and the surface of the work
-
piece melt as the arc is sustained for a
pre
-
determined interval.
•
At the completion of the pre
-
determined interval, the pistol returns the weld stud to the molten
pool on the work
-
piece, thus forming a weld.
The most common and traditional drawn arc welds have a weld duration greater than 100ms and employ
the use of a single use ceramic arc shield, commonly referred to as a ferrule. This ferrule helps to protect
the arc during the weld and assists in formation of the final fillet. Post welding the ferrule is removed and
disposed of.
It is possible to stud weld without a ferrule. This method is more commonly employed with welds having
a duration of less than 100ms and this type of weld is referred to as short cycle stud welding. Although no
ferrule is employed, it is recommended practice in short cycle welding to employ a suitable shielding gas
to reduce the amount of porosity in the completed weld and improve weld quality.
The DA8
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A range of pistols are what are commonly referred to as
“
fixed lift
”
pistols. This is because the
pistol does not include a clutch assembly in the lift mechanism. In practical terms this means that
although the lift can be user adjusted within its operational limits, should certain parameters change from
weld to weld, for example the studs to be welded vary in length or the surface being welded to being very
uneven, this will have an effect on the amount of lift during the weld and may impact adversely on the
quality of the finished weld. Because of this, we recommend that only properly manufactured weld studs
be used and that customers should always strive to weld to flat, even surfaces.
It is important to decide, based on your specific application, which model variant of the DA8
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A will be best
for you. For example. If you are welding standard drawn arc studs with ferrules, the standard DA8
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A
would be your choice whereas if your application calls for short cycle or CD type studs welding using a
template with 35mm positioning guides , the A2 would be the best choice. You could also select the A4
for this application providing that the studs to be welded are under 40mm in length as this is limit for stud
length in the A3 and A4 variants. See page 6 for an outline of the different model variants.
