When using bonded components it can occur that a bonded joint has to be repaired. This may be because a bonded joint has been damaged by an excessive load or because one of the substrates has been damaged, for example stone damage to a windscreen.
In these eventualities, a procedure must be laid down for repairing the bonded components such that they have the same load limit as the original bonded products. Consideration must be given here to:
- how the old bonded joint can be destroyed without damaging the substrates;
- how the new surfaces to be bonded must be prepared and pretreated;
- what adhesive must be used for the repair;
- how the adhesive must be applied and cured in the workshop;
- after what period of time can the bonded component be used again;
- what special skills are required by the personnel performing the repair work.
If you intend to repair a damaged bonded joint – like replacing the damaged windscreen in our example – then the repair procedure must be specified before the first repairs are performed. You should also specify whether a bonded joint must be checked during the usage phase by means of visible inspection or other non-destructive test.
We can help you select and adapt suitable non-destructive test methods for your regular checks. You can also count on us if you need ideas for how to repair a bonded joint or need assistance with verifying a specified repair procedure.
If, however, a bonded joint fails during its intended use then we recommend that you investigate the possible reasons for this in more detail. It is important here to determine whether there is a systematic failure or whether it is just a one-off case. Fraunhofer IFAM expertise in failure/damage analysis and process reviews is available to you here.