Powder coating and chrome plating are two popular metal finishing processes that produce durable, attractive, and protective coatings. But is it possible to powder coat over an existing chrome plated surface? And if so, what are the benefits, drawbacks, and best practices for powder coating over chrome?
Powder Coating and Chrome Plating
Powder coating and chrome plating are both finishing processes that are applied to metal surfaces to enhance their durability, appearance, and corrosion resistance.
What is Powder Coating?
Powder coating is a dry finishing process that applies a polymer powder to a metal surface using an electrostatic charge. The powder particles are sprayed onto the grounded metal, adhering due to the electrostatic charge. The object is then heated to melt and cure the powder into a durable, uniform coating [1].
Powder coating is valued for its:
- Wide range of colors and textures
- Excellent durability and scratch resistance
- Resistance to chips, fading, and corrosion
- Cost effectiveness
- Environmentally friendly process
Powder coated surfaces have a matte to glossy finish and are commonly seen on automotive parts, metal furniture, household appliances, and more.
What is Chrome Plating?
Chrome plating, also called chromium plating, is an electroplating process that applies a thin layer of chromium onto a metal object such as steel or aluminum. The chrome plating acts as a protective barrier, adding a bright silver-colored finish, hardness, and corrosion resistance.
The benefits of chrome plating include:
- Bright, mirror-like shine
- Extreme hardness and scratch resistance
- Protection from corrosion and tarnishing
- Enhanced wear resistance
Chrome plating is primarily used for decorative purposes in the automotive, motorcycle, marine, and plumbing industries. It is valued for its lustrous finish.
Is Powder Coating over Chrome Plating Possible?
Yes, it is possible to apply a powder coated finish over an existing chrome plated surface. However, there are some important considerations to keep in mind.
The keys to success are proper surface preparation, selecting compatible materials, and working with an experienced coatings professional.
Some of the reasons you may want to powder coat over chrome include:
- Changing the color from chrome to a custom color
- Improving corrosion resistance
- Adding texture or wrinkle effects
- Renewing an older finish
Overall, powder coating can provide excellent durability and appearance over chrome, as long as the correct steps are taken.
Benefits of Powder Coating over Chrome
There are several advantages that powder coating offers compared to chrome plating alone:
More Durable Finish
Powder coating forms a thicker, more durable coating over the chrome than chrome plating alone. The powder coated layer helps protect the chrome from wear, abrasion, impact, and corrosion [1].
Color and Texture Options
Powder coating allows for nearly any color to be applied over chrome, unlike chrome’s silver metallic finish. Textured powder coatings, like wrinkles or hammer tones, can also add visual interest [2].
Environmentally Friendly
Powder coating produces zero hazardous waste, unlike chrome plating which uses harsh chemicals. Powder over chrome is an eco-friendly way to update chrome parts [3].
Cost Effective
In many cases, powder coating over existing chrome is more affordable compared to stripping and re-chroming the part [4].
Improved Corrosion Resistance
The extra protection from powder coating enhances corrosion resistance, especially if the chrome plating has worn thin in areas [1].
Less Maintenance
Powder coating over chrome requires less maintenance and holds up better to daily wear and tear compared to chrome alone [4].
So in summary, powder coating can improve durability, allow for color/texture changes, is more eco-friendly, affordable, and corrosion resistant compared to chrome plating alone.
Drawbacks and Considerations
While powder coating over chrome has its advantages, there are some drawbacks and considerations to keep in mind:
Altering the Chrome Appearance
Powder coating will mute or alter the signature chrome shine, replacing it with a colored matte, gloss, or textured look instead [4].
Potential Adhesion Issues
Powder coating may have poor adhesion directly over chrome due to its smoothness. Proper surface prep is vital [5].
Reflectivity Differences
The reflectivity of powder coated chrome will differ from untreated chrome, which may be undesirable for some applications [2].
Preparation Challenges
Chrome is difficult to roughen for powder coating without damaging the chrome layer. Specialized tools and skills are needed [4].
Replicating Chrome’s Brilliance
It is challenging to exactly match chrome’s bright and mirror-like finish with powder coating [1].
So in summary, altering the original look, adhesion concerns, reflectivity, prep work, and mimicking the chrome finish are downsides to consider with powder over chrome. Proper planning and execution is key.
Step-by-Step Process for Powder Coating over Chrome
Successfully powder coating over chrome requires careful surface preparation and following a precise process. Here is an overview of the key steps:
Step 1 – Thoroughly Clean the Chrome Surface
- Remove any grease, oil, or other contaminants with a degreaser. This ensures proper powder adhesion.
- Use alkaline cleaners to remove soils. Rinse thoroughly with water.
Step 2 – Roughen the Chrome with Abrasive Blasting
- Abrasive blast with a fine grit media to create a uniform etch pattern.
- Lightly abrade the surface. Do not remove the chrome plating.
- This roughens the chrome for better powder adhesion.
Step 3 – Chemically Treat the Chrome Surface
- Applying a conversion coating or etching primer after blasting improves corrosion protection.
- Common options are chromate, phosphate, and zinc phosphate coatings.
Step 4 – Apply Powder Primer to the Chrome (Optional)
- For best results, use an epoxy or polyester primer powder before the topcoat.
- This further improves powder coating adhesion and corrosion resistance.
Step 5 – Select Compatible Topcoat Powder
- Polyester TGIC powders offer excellent adhesion and durability over chrome.
- Smooth low-cure powders provide better flow and appearance.
Step 6 – Apply Topcoat Powder
- Heat chrome to 400°F prior to coating to ensure proper powder cure.
- Electrostatic spray powder for uniform coverage.
- Apply multiple coats to achieve desired coating thickness.
Step 7 – Cure Powder Coating in Oven
- Follow powder manufacturer’s cure schedule for time and temperature.
- Typical time is 10 minutes at 400°F.
- Allow to cool slowly to avoid cracking powder.
Proper surface prep, priming, powder selection, application, and curing are essential in this multi-step process. Patience and care is needed for high quality results.
Powder Coating Methods for Chrome Parts
There are two primary methods for applying powder coating over chrome plated parts – sending parts to a professional powder coating shop or using a powder coating gun kit for small parts.
Professional Powder Coating Shop
For large chrome items like bumpers, wheels, or roll bars, a professional powder coating shop is recommended. The benefits include:
- Large ovens and equipment for any part size
- Wider range of primer and powder options
- Skilled technicians experienced with chrome
- Consistent, high-quality results
- Ability to mask off sections or disassemble parts
The process requires properly removing and transporting parts. Shop costs range from $100-300 depending on the size and complexity of the job.
Powder Coating Gun Kits
For small chrome parts, DIY powder coating gun kits provide a simpler and more affordable option. These include:
- Portable powder coating gun with air compressor
- Powder coating oven or electric skillet for curing
- Masking tape, blast media, degreaser, primers, powders, etc.
While convenient for small parts, DIY kits may produce inconsistent results on chrome. Professional help is recommended. Kits cost $100-500 depending on components.
Regardless of method, proper materials and preparation are vital for successful powder coating over chrome.
Best Practices for Powder Coating over Chrome
To achieve excellent results powder coating over chrome plating, follow these best practices:
- Consult with the powder coating professional to select the ideal primer and powder for chrome.
- Completely disassemble parts if needed to ensure full coverage and proper curing.
- Mask off any rubber gaskets, plastic sections, or areas you do not want coated.
- Perform abrasive blasting lightly to avoid removing the chrome layer.
- Use zinc phosphate or chromate coatings after blasting for superb corrosion resistance.
- Apply multiple thin coats of powder rather than one thick coat for best appearance.
- Cure powder fully according to manufacturer guidelines to ensure optimal bonding.
- Inspect the finished coating for any flaws and repair as needed.
- Consider adding a clear top coat over metallic powder colors to enhance reflectivity.
Taking the time to properly prepare the chrome and carefully apply and cure the powder will provide long-lasting, attractive results.
Powder Coating over Chrome on Wheels
One very common application of powder coating over chrome is for automotive wheels. Powder coating provides excellent protection for chrome wheels while adding custom color.
For best results on chrome wheels:
- Strip the tire from the wheel and remove all hardware.
- Use aluminum oxide blasting media at low pressure. This effectively abrades the chrome without removal.
- Clean and degrease thoroughly after blasting.
- Apply two coats of a zinc-rich epoxy primer formulated for wheels.
- Use a high-gloss polyester powder for the topcoat. Smooth “low-cure” powders have better flow.
- Apply three coats of topcoat powder for maximum protection.
- Cure according to powder manufacturer’s recommendation.
- Reassemble wheel and mount tire after coating has fully cooled.
With the right products and process, powder coated chrome wheels maintain their durability while offering custom colored finishes.
Maintaining and Repairing Powder Coated Chrome
Powder coating over chrome provides excellent durability and corrosion resistance. However, it does require some occasional maintenance and repair.
- Wash regularly using automotive detergent, avoid harsh abrasives
- Touch up any damaged areas immediately to prevent corrosion
- Reapply topcoat powder if corrosion appears underneath
- Spot repair any severe damage – scuff, recoat area
- Avoid overheating powder coating when welding on chrome parts
- Re-blast and re-coat the entire part if damage is extensive
With minor touch-ups over time and proper care, powder coated chrome parts can last for many years before needing a full re-coat.
Does Powder Coating Prevent Chrome from Rusting?
Powder coating provides an added layer of defense against rust and corrosion forming on chrome parts. The powder topcoat seals the porous chrome plating, helping prevent oxidation.
However, powder coating only helps prevent rusting if applied properly over well-prepared chrome. Blasting is essential to roughen the surface for powder adhesion. Any pinholes or imperfections in the powder topcoat leave the chrome vulnerable to corrosion.
For maximum rust prevention, a zinc-rich primer should be applied before powder coating to protect the chrome in case of coating damage. Overall, powder over chrome improves corrosion resistance but does not guarantee the chrome will not eventually rust without proper maintenance.
Should You Powder Coat before or after Chrome Plating?
Powder coating before or after chrome plating each have their own advantages and disadvantages:
Powder Coating First
Applying powder coating to a part before chrome plating provides excellent corrosion protection underneath the chrome layer. This is ideal for automotive trim and accessories.
However, the powder coating process can leave imperfections in the base metal finish that reflect through the smooth chrome plating. This can negatively impact the chrome’s brilliant mirror-like finish.
Chrome Plating First
Chrome plating first allows for a perfect, highly reflective chrome finish. The part can then be powder coated over the chrome for increased durability and custom color.
On the downside, chrome plating alone provides no corrosion protection between the base metal and the chrome layer. Damage to the powder topcoat leaves the chrome at risk.
Conclusion
For non-cosmetic automotive parts and tools, powder coating first is preferred to protect the base metal before chrome plating. For decorative chrome parts like wheels and trim where appearance is vital, chrome plating first provides the best looking finish.
Can You Powder Coat Plastic Chrome Parts?
Many automotive trim pieces and emblems have a chrome plated plastic finish. Can these plastic parts be powder coated?
Unfortunately, attempting to powder coat plastic chrome parts is extremely challenging and typically ineffective:
- The plastic chrome plating is very thin and will not withstand abrasive blasting. Blasting will damage the plastic substrate.
- Plastic chrome parts are thermally sensitive. The high temperatures during powder curing can warp or melt the plastic.
- Powder coating does not adhere well to the smooth plastic chrome plating without proper surface preparation.
- Static can attract powder unevenly resulting in a blotchy, inconsistent finish.
- Off-gassing from the plastic during curing can ruin the powder’s flow and cure.
In general, it is not recommended to powder coat over factory plastic chrome parts. The plating is too delicate and the plastic cannot withstand the coating process. Opt for a high quality spray paint instead.
Professional vs DIY Powder Coating over Chrome
Is it better to powder coat over chrome yourself using a small DIY gun kit or have it done professionally?
For most applications, professional powder coating will provide superior results over DIY methods.
Advantages of Professional Powder Coating:
- Access to a wide range of specialty primers and powders
- Large-scale equipment for any part size
- Even coating and proper film thickness
- Curing ovens prevent flow defects
- Experienced technicians familiar with chrome
Limitations of DIY Powder Coating:
- Limited selection of powders available for purchase
- Small parts only, large parts won’t fit in home ovens
- Powder applied too thickly or thinly
- Inferior cure quality in home ovens
- Less experience working with challenging substrates like chrome
For valuable chrome parts, the minor extra cost of professional powder coating is worthwhile to ensure correct preparation, high-quality application, and durable cure. DIY is best for small, non-critical parts and beginners.
Conclusion
Powder coating over chrome plated metal is an excellent way to increase durability, allow for color changes, and provide extra protection from corrosion. With proper surface roughening, primer selection, and application technique, powder can adhere strongly to chrome for a long-lasting finish.
Pay special attention to the preparation process, choosing compatible primers and topcoats, and properly curing the powder. Although difficult, powder coating over chrome is certainly feasible and worthwhile for both decorative and functional metal parts in a range of industries.
References:
[1] Eastwood. “Powder Coating over Chrome.”
https://www.eastwood.com/eastwood-knowledgebase/can-you-powder-coat-over-chrome-plating/
[2] Prismatic Powders. “Powder Coating over Chrome.”
https://www.prismaticpowders.com/blog/powder-coating-over-chrome
[3] Axalta Coating Systems. “Powder Coating vs Chrome Plating.”
http://www.powdercoating.org/page/PowderVsChrome
[4] Powder Coated Tough. “Powder Coating vs Chrome Plating.”
https://www.powdercoatedtough.com/powder-coating-vs-chrome-plating
[5] AkzoNobel. “Powder Coatings over Chrome.”
https://www.interpon.com/en/blog/powder-coatings-over-chrome
