The authoritative public forum
  for Metal Finishing since 1989
-----

Contamination prevention for powder paint in tapped holes

2000

Any suggestions as to how to prevent powder paint and pre-treatment from contaminating machined features, (primarily tapped holes) in a large steel structure? Currently structure is pressure washed using a phosphatizing cleaner before applying powder coat paint.

In some cases, paint bleeds into plugged holes. Other times, a black grit is removed from holes.

Is this simply the "nature of the beast", or is there a solution that would eliminate the time consuming process of inspecting and cleaning out the holes before fasteners can be inserted?

Mike Yelenik
- Binghamton, New York

---

Try silicon pull plugs. Insert before phosphate and it will keep the chemicals and paint out. There is one or two other materials that will stand the powder bake temperatures.

There is a learning curve on plugging, so do not expect instant flawless results.

James Watts
- Navarre, Florida
2000