How to Remove Powder Coating
Many methods have been used to remove powder coating from production hooks,racks,and fixtures.
- Abrasive-media blasting
- Burn-off ovens
Benefits. Abrasive-media blasting is a common method used in the finishing industry to clean electro-deposition and powder coatings deposits from racks. Abrasive-media blasting provides adequate cleaning and coating removal. One of the benefits of rack cleaning with abrasive media is any rust or oxidation that may be present is removed with the coating, and this is accomplished at ambient, or room, temperature.
Concerns. Using abrasive media to clean racks on a regular basis results in loss of metal. This means that over time the racks must be completely replaced. Another concern associated with this method, is the residual blasting media, if not completely removed from the racks can create dirt contamination upon subsequent use. In addition, abrasive media is often carried out with the racks and distributed on the plant floors, creating safety concerns. The cost of abrasive- media replacement must be absorbed by the end user.
Benefits. The burn-off oven method provides adequate results for coating removal. The benefit of the burn-off oven is the coating buildup on the rack can accumulate from 3 mils to more than 50 mils in some cases, and the burn-off oven continues to provide adequate cleaning results.
Concerns. Burn-off ovens operate at temperatures up to 1,000°F for durations of 1 to 8 hours. These temperatures and cycles over time can cause stress, brittleness, and metal fatigue on the steel rack substrate. In addition, residual coating ash is left behind on the rack surface after burning and must be removed by pressure water rinse or acid chemical pickle to prevent dirt contamination. The cost of gas (energy) to operate a burn-off oven must also be absorbed by the end user.
There is another way to remove powder coating used at present, that is liquid removals.