The authoritative public forum
  for Metal Finishing since 1989
-----

Can an aluminum piston be plated to restore compression?

I am wondering if there is a plating/anodizing process which could restore the piston/sleeve fit in a tiny ringless 2-stroke hobby engine.I think the piston is made of a high silicon aluminum in order to precisely control heat expansion. the sleeve is usually aluminum or nickel which is plated with a hard chrome finish and is tapered for maximum compression at the end of the stroke. usually the piston wears out faster than the sleeve. even .001 inch can make the difference between like new and worn out. operating temps are a concern at 250 plus degrees as measured from the outside of the engine.

Thomas K. Montgomery
serious hobbyist - Duncansville, Pennsylvania, U.S.A
2006

---

Electroless nickel plating can be done to add .001" You might also try aerosol epoxy/molybdenum disulfide, which you can do at home. This sort of coating is being used on pistons in many new cars.

Jeffrey Holmes, CEF
Spartanburg, South Carolina
2006