When to Touch Up

Question:

We have a spray booth with eight automatic guns at the entrance and a manual touch-up opening and gun at the exit. This means that we touch-up the parts after the automatic guns have done their work. We have problems getting powder into the recessed areas using this methodology. We now touch-up the parts in a batch off-line booth and then hang the parts onto the conveyor line to be coated by the automatic guns. This seems to work the best. Should we rotate the openings within our booth to allow for touch-up before the automatic guns? M.B.

Answer:

Yes. Many parts are coated better when the touch-up is performed before the automatic guns. Reversing the openings within your booth should be relatively easy, since most manufacturers use commonly sized panels. Be sure not to increase the size of the openings since this can allow the booth to leak powder into the plant. Certainly relocating the openings within the booth will ensure that you coat your products more efficiently using your on-line process with less handling of the parts onto and off the conveyor line.