100c
User Manual
30
ch
.
4
Sometimes it can be helpful to focus the energy of a resistance weld for larger parts . This can
be done by using a weldment, or bump between the parts to be welded . This bump forces the
electrical current to pass through a concentrated point (especially important for thicker parts) .
The smaller the bump tip diameter the more heat that can be generated at that point . This
technique is also very helpful for welding dissimilar, conductive metals . For example, resistance
welding silver to gold can be difficult, however, if I place a gold weldment on the silver part the gold
to gold resistance weld become very simple .
To aid in resistance welding difficult thicknesses or material combinations
. 1.) Place a weldment or
bump on one side to focus the energy. 2.) Use an electrode configuration that is simple and has
as much contact area as possible on the outside of the parts. 3.) The weldment or bump will fuse
into the other part making a resistance weld that cannot be seen on an edge.
TIPS WHEN RESISTANCE WELDING
With the above in mind there are several different helpful recommendations to use when
resistance welding .
1 . The pressure between the two parts is the most important variable in resistance welding; even
the amount of energy being used for the weld plays (to a degree) a lesser role .
2 . High pressure will create a cool weld .
3 . Light pressure will create a hot weld .
4 . No pressure will produce an arc!!
5 . Placing a small bump or weldment between difficult to weld parts can simplify the welding
process .
If using tools to hold the work pieces remember that firm pressure between the tool and the work
piece is important to prevent welding the tool to the work piece (e .g . brass lined pliers) . Then
apply the correct pressure between the work pieces to achieve your weld .
HANDS ON: Try turning the Tack Mode energy to 50 Ws and make a weld:
1 . First weld with very firm pressure between the parts . The result may be little or no weld .
2 . Next clamp the parts firmly in the tool but apply virtually no pressure between the parts (make
sure these are parts you no longer need) . The result will be a very large spark, or at least a
much better weld .
3 . Practice at different energies and pressures until you feel comfortable with the process and
results .
The pressure between the tool holding the part is also very important . If insufficient
pressure is applied between the tool and the part the weld may take place between
the tool and the part . Always grip the part firmly in the tool to reduce the contact
resistance between the tool and work piece . Doing this will reduce the amount of
heat created where the tool and part meet .
