Nelson N800iTM, Operation And Service Manual, Page: 7 / 142

Tucker GmbH, Mail / Post: Max-Eyth-Str.1, 35394 Gießen, Germany
Stud welding unit N800i
As of 24.08.2021
Manual part number: BE 1227
3
See the pertinent gun operating instructions for knowledge on hand
‐
ling weld guns in a
professional and safe manner.
The bright dot matrix display shows the function codes in plain text and can typically
even be read in sunlight.
1.3 Welding Method
Commercially available studs with a diameter of up to 12mm can be welded with the
Nelweld N800i welding unit both in keeping with:
•
the short
‐
cycle method (7mm)
•
the drawn
‐
arc method (10mm).
The drawn
‐
arc method serves to full
‐
surface weld studs of specific geometric
dimensions to metallic workpieces, which should have a wall thickness of at least ¼ of
the stud diameter.
In order to guarantee deoxidization of the weld pool and to better ignite the arc, the
foreparts of the studs to be welded mostly have an ignition peak of aluminum.
It is preferable to use ceramic ferrules to protect the weld pool against atmospheric
oxidization and contain the molten liquid metal in order to center the arc. In addition to
this, the molten metal is prevented from cooling too quickly.
When welding overhead or in a horizontal position the ceramic ferrule ensures that the
weld bead always has a constant shape and provides the user with protection against
spatter.
The short
‐
cycle method is a variation of the drawn
‐
arc method, which in extremely short
weld times makes no special demands of the type of stud tip.
With the exception of the shorter weld times, the operational sequence is identical with
that of normal arc welding.
In keeping with the short
‐
cycle method welding studs can also be welded on coated with
oil contamination workpiece surfaces, the mini
‐
mum plate thickness of which should not
exceed 0.6mm.
On account of the extremely short weld times the studs can also be welded without
ceramic ferrule. To protect the weld pool, particularly with aluminum welds, it is advisable
to use inert gas.
The introduced inert gas displaces the air from the welding zone. If welds are to be
carried out under inert gas, it is preferable to use studs with a tapered welding tip.