the primary aim in this application is the removal of thick dirt, old coatings and rust. in years of practical tests we have developed nozzles with razor-sharp water jets for this application. the aim was to prepare for the new coating in an optimum manner, without the risk of deforming the sheet metal. also, intact zinc coatings must not be damaged unnecessarily or removed. today we can offer very substrate-protecting and economic solutions with our professional units which have the least possible recoil forces.