Often it is desirable to keep the powder material from reaching certain areas of the article being processed. Tight tolerances and electrical grounding contact areas will require masking. There is a number of ways in which to accomplish this, the following methods are of the most popular in use today.
Tapes and discs – Heat resistant tape is a very common masking technique that is often used. Whether pre-cut to the desired size and shape or purchased by the roll, tapes are a cost effective way to mask most parts. Caution should be taken in the selection of the adhesive material that the tape is made of. During the baking process the tape’s adhesive may also be baked on leaving an undesirable gummy surface that would require a post cleaning operation.
Caps and Plugs – Commercially available in a variety of shapes and sizes that will withstand post bake temperatures up to 600 degrees.
Racking system – The design and configuration of the racking system can often serve as a masking device.
Air mask – A low pressure blast of air can remove powder that is electrostatically attracted to the ambient surface. This process must be accomplished prior to the baking cycle.
Vacuum masking – This can be accomplished in much the same manner as the air method described above. The advantages of this method are a cleaner process and a sharper break line.
Foil wrap – This can hide the surfaces that do not require coating. This application is desirable on many large surfaces that would be difficult and timely to tape.
Other materials have been used such a silicone rubber, wood, cardboard, magnets, spray on anti-stick compounds, brush-on compounds, high temperature grease, hot and cold dip plastisols, and a variety of others.
Have questions about masking, or any other part of the powder coating process? Give one of our service experts a call at 888-647-9929 or email us at firstname.lastname@example.org, and we can get you headed in the “Rite” direction!
Thanks to one of our customers KVF Quad for loaning us these before and after pictures! A great example of proper masking!