Custom Masking Designs for Powder Coating and E-Coating

In this post, we will take you through various custom masking designs Echo has designed and manufactured for some of the biggest brands' powder coating and e-coating lines (and explain their purpose).  What we've seen over the years is that many coaters have issues related to masking, but they don't know where to start.  We hope you can review this post and find a solution or inspiration for improving your line's output!

Custom Masking Designs

Below, we've listed a variety of designs that have been used to solve issues, such as plugs blowing out, leakage, paint buildup, etc., for powder coaters and e-coaters worldwide.  These designs are typically tailor-made to specific customers' needs, which you'll get if you go down the path of custom masking with Echo.  If you have any questions or would like to request a quote at any point, feel free to contact us using the form at the end of this post.

Vent Plugs

A common issue coaters encounter is having their masking plugs pop out as heat builds pressure.  One method of dealing with this issue is by implementing a vented design.

The way it works is by putting a slit into the plug, which allows pressure to release (without allowing the paint to leak in) and then closing up when the external pressure exceeds the internal pressure.

The image shown here is actually a "cross vent plug." That means the vent is covered up to prevent shot blast media from entering the mask.  It's also a way of preventing extra powder from sitting out top, allowing powder coaters to get more uses out of the plugs.

Pop Pin Masks

Another way to vent pressure is via a "pop-pin" masking method. When enough pressure builds up, the top portion (the pop-pin) allows the air/pressure to release without allowing e-coat / paint to leak in.

The pressure being released prevents leakages, but once the pressure escapes, the top pin returns to create a seal.

Magnetic Masking

Magnetic masking is a great option for powder coaters who want to mask off a flat/mating surface without anything to grab onto and don't want to deal with masking tapes.

These are some of the fastest-to-install masking solutions you'll find, and it all comes down to the design and magnet used.

Flanged Caps / Plugs to Reducing Powder Buildup

Powder building up (or "bridging") against a masking cap/plug is a big problem that powder coaters face. There are several ways of reducing the chances of powder building up, but a common solution is to design a mask with a flange wrapped around it at an angle (like an umbrella or a skirt).

High-Temp PPS Plastic Threaded Plugs

PPS plastic can also be used in high-temperature scenarios. One application could be masking a threaded hole and the grounding area. The silicone washer acts as a high-temperature seal, while the PPS component works to easily and consistently install the mask and ensure it stays in place.

Clamshell Masks

A cap or plug occasionally won't do it, so there are clamshell masking designs.  These masks work by wrapping around the product needing to be masked and then pulling pull plugs through to lock the design in place.

Expandable Masking

If you're looking for highly engineered masking solutions (at least when compared to standard caps and plugs), this is a prime example. Expandable masks work by combining high-temperature plastic with silicone.  When the lever/handle is pushed down to the lock position, the plastic pushes out, resulting in a tight seal between the component and the silicone.  This makes an excellent method of preventing leakage during e-coat.

Rubber + Metal Bolt Hybrid Masking

A method of masking threaded holes can be by over-molding silicone onto a bolt.  This ensures a tight fit without worrying about the bolt's temperature resistance.  Like the image shown here, the silicone will typically be part of the design as a way of creating a seal and masking off the chamfered area.  This is also a great way of preventing plug blowouts as well.

Screw Together Masking

An alternative method to using one super long pull plug or two push plugs that may be at risk of blowing out is by switching to screw-together masking solutions.  As you can see in the image here, the design works by having a male and female component where the bolt portion goes in on one side and screws together with the opposite side.

The benefit of this method is that you can hand-tighten it to your desired needs to ensure no leakage occurs. Customers can also use PPS as an alternative to metal bolts.

Custom Die-Cut Masking

Custom molded masks are not always the best option, especially for lower-volume projects or crucial time constraints. In those cases, we recommend custom die-cuts shaped to your exact requirements.

Masking Sleeves for Bores & Bushings

Custom-designed masking sleeves are now a popular method of masking off bores and bushings. These require knowledge of rubber durometers, thicknesses, and design to get correct, but luckily, our engineers are experts at them.

Conductive Silicone Masks

A common request we get is that our customers want to be able to hang their parts by the mask. To do this, we add carbon black to the silicone to make it conductive, which then gives powder coaters the ability to hang the part.

Molded Masking Designs for Mating Surfaces

Mating surfaces must be masked off, which can be tricky without adhesive. When there is an opportunity to do so - such as a wheel's mating surface - we can develop custom-molded masking designs that use holes/threads/openings that also need to be free of coating.

Conclusion

Custom masking is one of the many methods of improving a metal coating line's efficiencies.  If you're dealing with lower volumes, most likely, you'll want to stick with catalog options. We suggest doing a time study and comparing the price of a custom masking option. Learn more about what this takes here: Purchaser's Guide for Custom Masking

We understand entirely how masking operations can end up being one of the last few items on your to-do list, but don't corner yourself by pushing it off.  Custom-molded masking requires engineering design, prototyping, tooling,  and time to get parts molded and shipped.