DIY Cerakote Pistons for K800, Super X, and Super Sport

High-performance coatings aren’t just for factory teams. With patience and clean process, a home workshop can apply real motorsport tech to vintage engines. I set out to coat piston skirts and crowns for my Zundapp K800, plus an Excelsior Super X and Super Sport, using Cerakote products. Here’s the full photo walkthrough, with the little things that made the big difference.

Why bring motorsport coatings into a vintage garage?

Cerakote’s reputation in thermal and friction-reducing coatings is hard to ignore. They hold a stack of patents and have a deep footprint in automotive applications, which gave me confidence to take the plunge at the bench rather than sending parts out again.

I’ve seen great results from others and figured it was time to run the same play on three very different pistons: K800, Super X, and Super Sport. If it stands up across that spread, it’ll stand up anywhere in my fleet.

Prep matters more than the paint

The most important lesson: follow the process. I started with a full immersion degrease in acetone to evict every trace of oil. It’s not glamorous, but it’s the foundation everything else stands on.

With the surfaces surgically clean, I masked the crowns using high-temp tape. Keeping the crown clean at this stage lets me control exactly where each coating goes later.

I also corked the pin bores with natural plugs. It’s a simple trick that keeps media and coating out of precision fits without leaving adhesive residue.

Give the coating something to grip

Into the blasting cabinet they went. Using a very fine media at low pressure, I lightly abraded the skirts to a consistent matte. The goal is keying, not cutting.

This micro-etch is essential for adhesion. A slick surface looks pretty, but coatings bond best to a controlled tooth—this quick step pays dividends in durability.

Pre-bake: clearing moisture and volatiles

Before any coating, I preheated the parts at about 300°F (150°C) for 30 minutes. This drives out trace moisture and prepares the aluminum to accept the film evenly.

Low-friction skirts, better oil behavior

With prep done, I sprayed the skirts with Cerakote’s friction-reducing coating. It’s thin, uniform, and designed to help oil film formation—exactly what old-school cylinders appreciate.

I built two light coats and then cured them at 300°F (150°C) for an hour. The bake links the resin system and takes the coating from “wet” to work-ready.

Post-cure, the sheen turns slightly more matte—a nice visual cue that the chemistry has set. I love that moment when the surface telegraphs “ready.”

The first reveal: demask and grin

Peeling the masking is always the satisfying bit. Even at this stage, the pistons start to look purposeful—like they’ve been to boot camp.

Here’s one from the Excelsior lineup—same process, same finish, equally mean.

And a K800 slug to match—nothing like seeing the set come together across different platforms.

Add a thermal shield to the crowns

Next, I switched focus to the crowns and set up for a heat-reflective barrier. Keeping combustion heat out of the piston is free insurance in old engines.

As with the skirts, I first matted the crown surface so the barrier layer has something to lock into. Clean, even tooth beats shine every time for adhesion.

There’s the finish I was after—uniform, clean, and ready for the thermal spray. That little “ah, just right” moment always makes me smile.

This crown coating forms a thermal barrier between the fire and the aluminum. The idea is simple: shed excess heat into the exhaust stream instead of soaking it into the piston.

We’ve all seen photos of holed pistons, old and new. This layer aims to reduce that risk by resisting localized hot spots.

Heat cycles and the final touch

Just like the skirts, I preheated for 30 minutes before applying the crown layer, then returned the pistons to the oven for the cure. Consistency is everything.

The curing session for the crowns ran another hour at about 300°F (150°C). I won’t pretend that waiting isn’t the hardest step—I kept pacing by the oven.

Per the manufacturer’s guidance, I burnished the cured coatings with the finest grade steel wool. It’s a gentle pass that knocks down any micro high spots without changing thickness.

And yes, I did both the skirts and crowns this way—no shortcuts. Those small, careful touches are the difference between “done” and “done right.”

Finished pieces and why this matters on the road

Here’s the payoff: a small gallery of the finished pistons. The coatings look factory-clean, but more importantly, they add a margin of safety.

Alongside the photos, here’s the “why”: adopting proven coatings helps these old engines cope with modern usage without changing their character.

Vintage bikes aren’t “easier” than modern ones—they’re just different, and a bit less forgiving in certain areas. Coatings help bridge that gap.

Many older engines run hotter and oil systems can be marginal by today’s standards. Lower-friction skirts and a reflective crown are small upgrades with an outsized effect.

In modern stop‑and‑go traffic, these bikes face loads they never saw when new. This treatment is my way of giving them a fighting chance—and yes, the finished look is fantastic.

Frequently Asked Questions

Q: Will these coatings change piston-to-cylinder clearances?
A: The applied films are very thin when sprayed correctly. I keep the skirts within the expected tolerance band and confirm fit during mock-up, just as I would with any fresh piston.

Q: Do coatings fix worn pistons or cylinders?
A: No. They’re not a band-aid for wear. I only coat good parts—straight bores, proper taper, and roundness. The coatings add margin; they don’t replace machining.

Q: Why both a skirt coating and a crown barrier?
A: Different jobs: the skirt layer reduces friction and helps oil film behavior; the crown barrier resists heat soak and hot spots. Together, they make life easier for an old engine.

TL;DR – Quick Recap

• Chose Cerakote friction-reducing and thermal barrier coatings for K800 and Excelsior pistons.
• Meticulous prep: acetone degrease, high-temp masking, corked pin bores.
• Light blast to a matte finish for adhesion; pre-bake at ~300°F (150°C).
• Sprayed two light skirt coats; cured an hour; confirmed the matte set.
• Applied thermal barrier on crowns; cured again after a preheat cycle.
• Final burnish with ultra-fine steel wool to smooth any micro high spots.
• Result: cooler crowns, friendlier skirt behavior, and pistons that look as tough as they’ll run.