Not sure when you should be using a new silicone mask? There are multiple signs you can look for to tell if a mask needs to be replaced. Don’t let there be failures or quality defects/rework by overusing the mask.
How Many Times Can You Use a Silicone Masking Part?
Silicone is the ideal option for masking when you you have a high-temperature curing process due to its extreme heat resistance. Because of this, powder coaters can typically get roughly 10-20 uses out of them before they need to be replaced. This is just a general rule of thumb because silicone masking caps and plugs come in a variety of shapes and sizes that will impact their durability.
Other areas that you need to factor in when estimating how many times each piece will last include:
- Temperature used in your curing oven (higher temperature will deteriorate the silicone faster)
- Time spent in the curing oven
- The method you use to clean the caps and plugs
- Distance from curing oven hot spots will even play a factor. Your oven may be set to 600F, but that doesn't always mean that's the temperature the plug is going to end up having to endure.
Signs That You Should Replace Your Silicone Masking Cap or Plug
If you've reused rubber masking caps and plugs before for your powder coating operations, then you likely know that it doesn't take long before paint start beginning to buildup. Outside of the caps and plugs no longer actually being able to mask correctly because of overuse, there are a few other signs to look out for to let you know it is time to switch them out for a fresh batch.
A silicone mask will lose its color when it needs to be replaced. Colored masks will fade, and clear masks will turn tan/brown. This form of deterioration is the earliest warning sign that you'll need to start considering switching out your masking parts.
Firmness / Texture
A silicone mask may also become soft and spongy. The silicone mask becomes “gummy,” puckers, and is soft to the touch. This causes the mask to ineffectively mask the parts that need to be protected from paint, debris, etc. This is caused by overheating and the use of chemical cleaners. If the parts are used in a low-temperature cure or not run through the oven, this may not be an issue.
A silicone mask can also crack on the surface and increase in hardness, signaling overuse.
Excessive Paint Build-UP
Excessive paint build-up due to overuse will affect the ability of the mask to accurately mask the desired (and only the desired) area. Many times, excess paint can flake off, causing quality defects.
Time / Labor
The amount of time, labor, and product used to clean the silicone caps and plugs exceeds the value of the masking parts themselves.
How Can You Clean Masking Caps and Plugs?
We've spoken to many of our customers that powder coat, and while there are several methods of cleaning off paint buildup from your caps and plugs, here are some of the most common methods they use.
- Chemically Stripping your masking parts - If you choose this path, you'll need to consider the stripping agent's cost and the time spent on this process. In some cases, especially smaller masking parts, it's more cost-effective to replace the masks.
- Vibratory Polisher with "tiger teeth" media.
- Modify old washing machines and dryers and add media to get paint off of masking material.
- Manually peeling the paint off.
After testing your mask, you know how many times you can run it through whatever process is needed. After that, scale the use down 10% to 20% of the time it took for the mask to completely run down. If you know you can run it ten times before failure occurs, use it 8 to 9 times. This ensures that there won’t be failures or quality defects and rework.
Have different colored masks for different time periods. Say you know a mask will fail every month. Have a certain color for even months and a different color for odd months. This is a simple solution to ensure your masks do not fail due to overuse.