One of the most popular ways to finish metals is to use paint. Traditional automotive paints and newer powder paints (powder coating) require baking to achieve the correct finished look. In this post I will be discussing the options that are available for each.
A big limiting factor is that automotive paints and silicone don't mix. Any contamination by silicone prevents the paint from drying correctly. This is a bummer because silicone adhesive is capable of withstanding much higher temperatures for longer periods of time than acrylic or rubber adhesives.
Because of this I can only recommend a high temperature crepe paper masking tape. This is like regular masking tape except it has a much higher temperature range. These tapes can generally withstand 325ºF (163ºC) to 350ºF (177ºC) for between 30 minutes and 1 hour. You should always check the manufacturer's spec sheet to make sure of the parameters. After the bake cycle these tapes will remove cleanly, generally in 1 piece. If you bake the tape at a lower temperature you can get a longer exposure to the heat. If you drop down to 230ºF (110ºC) you can go from a bake cycle of 30 minutes to 1 hour. These tapes are generally used in roll form but die-cut shapes are available. Even if you aren't baking, I recommend using the high temperature masking tape because it will remove easily without leaving residue.
Another automotive tape that has high temperature application is fine line masking tape. Fine line masking tape is much thinner in cross-section that standard masking tape so there is a smaller ridge of paint build up along the masking line. These tapes are often used in pin striping and other detail work. They can usually go to 250ºF (120ºC) for up to 30 minutes.
Powder coating is a process where dry paint (powder paint) is sprayed onto the item to be painted. The item is then placed in an oven and baked at temperatures up to 400०F (190ºC). The powder melts and flows together creating a durable, seamless finish. This requires the use of silicone adhesives that can withstand up to 500ºF (245ºC) for an hour or more.
There are two tapes that are used for the majority of masking in powder painting; polyimide
and polyester. The polyimide is a sort of bronze/brown color and the polyester is usually green. Both of these tape are available with silicone adhesive. The big difference between the two is that the polyimide backing can go up to 500०F (245ºC) while the polyester backing can only go up to 400ºF (190ºC).
Many parts that are powder coated have surfaces that need to remain free of paint for a variety of reasons. In some instances you can use standard rolls of tape but many times the pieces need to be die-cut into a special shape. Thankfully this is easy to do.
The last type of tape for powder coating is self-fusing silicone tape. It is used on tubes or rods where you are wrapping the tape completely around it. This tape has no adhesive on it so it can't leave residue. To use it simply overlap it slightly and it will bond to itself. To remove just cut it off.
If you have any questions or if you need samples of these tapes please feel free to get in touch at 1-800-882-7348 or sales@taperite.com.
Happy Taping!!
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