When a manufactured part is powder coated there may be certain areas of the surface that must be free of coating. For example, threaded areas may not fit properly if they are coated. Bearing surfaces with close tolerance cannot be coated. Some parts may require a bare spot for electrical-grounding contact. It is important to select a mask that is effective, easy to use and reasonable in cost.
Masking parts will add additional labor to the coating process. It is important to understand the different types of masks that can be used. Masking can be as simple as placing a plug in a single hole or it may require a specially made mask or fixture. One large hole in a large part will require very little labor while some smaller parts may have numerous spots that need masking and require a lot of labor. Selection of the right masking procedure will affect the cost of the part.There are many commercially available masking materials for powder coated parts.
These cost and benefit issues are considered to determine the best possible way to mask a part:
- the cost per mask
- the number of times it can be reused
- the effectiveness of the mask
- the ease of application and removal
- ability to leave a clean parting line between the mask edge and the coating
- the need to be stripped and the prequency
- the temperature resistance of the mask material
- the ease of removal of adhesive backing
There are the following main types of masking products in EPSI's line:
- Tape and Discs
- 3M Tape and Discs
- Tubing and Cord