Overview of Surface Pretreatment Techniques

Surfaces can, generally, be pretreated using one of the following procedures for many substrates, this list is in increasing order of effectiveness  

of course, does not apply to wooden structures. Here, the same pretreatment is used today as was instigated in 1942, namely sanding along the grain. 

Care must be taken to avoid contaminating the surfaces during or after pretreatment. Contamination can be caused by finger marking, by cloths which are not perfectly clean, by contaminated abrasives or by sub-standard degreasing or chemical solutions. 

Contamination can also be caused by other work processes taking place in the pretreatment and bonding areas. Particularly to be excluded are oil vapours from machinery, spraying operations (paint, mould release agents, etc.) and procedures involving airborne powdered materials. 

Whatever procedure is used, it is a good practice to bond the substrates as soon as possible after completion. It is then that the surfaces are most active — i.e. their surface properties are at the optimum level for bonding. 

---