Combined Joining Processes
Combined joining processes are regularly used both in standard production and during repairs.
In the case of resistance-spot welding, all bonding surfaces and spot welds are replaced during repairs.
In this case, the unhardened adhesive must be displaced from the joint area by observing an appropriate hold-back time before actually starting resistance-spot welding.
In the case of two-component adhesives, the hardening reaction starts immediately after mixing and application; this increases the viscosity and so there is only a certain time window in which spot-weld bonding can be performed if the process is to be reliable.
For this reason, all time-intensive preliminary work (drilling, cutting to size, fixing etc.) on the parts to be joined must be performed before application of adhesive and joining.
This also applies to mechanical joining processes where the adhesive has to be displaced from the joint area, e.g. riveting.