Cleaning the parts of the Snoopy?s Continental engine

Suomeksi

As soon as parts had been detached from the Continental A 65 engine that we had received for the Snoopy (OH-XEA), originating from a plane destroyed in an accident, they were cleaned. Besides being physically damaged, the engine had also burnt. Unfortunately, many of its devices had been destroyed useless, so the missing parts also had to be searched for.

Photo by Erkki Rossi.

Small metal parts with little or no damage were cleaned from rust by bathing them 24 hours in 33 % solution of phosphoric acid. For example, the propeller hub, detached from the engine and dismantled into its parts, was all immersed into phosphoric acid.

When the acid starts working, foam will be forming on its surface. After a day and night, those propeller hub parts were taken out and carefully dried with fabric. As a result, the parts are rust-free, with dark grey clean surface. Even as such, the parts are fully usable.

However, we decided to blow the propeller hub parts with glass bead blasting to bright metal, to make them appear as brand new. One might ask, why not blast them straight away as rusty. We chose this approach to avoid contaminating of the glass blast media with rust enriching into it.

For aluminum engine parts with dirty surface, we chose another procedure. Aluminum parts that were dirty or blackened after burning, such as magnetos, were first cleaned of dirt and thereafter their surfaces glass bead blasted. Before the blasting, holes in the magnetos were plugged with wooden plugs to prevent the blast media from penetrating into the magneto. With the blasting, the magnetos got clean surfaces. Finally, the clean surfaces were treated with a solution of Sinol and water to prevent the oxidization of the surface.

Oily and dirty parts were initially washed in a basin dedicated to cleaning engine parts, with a handy brush that feeds washing liquid through a hose.

The washed parts were dried with pressurized air, aluminum parts then possibly treated with glass bead blasting and Sinol-water solution. This method was chosen e.g. for the aluminium distributor head cover.

Photos by Lassi Karivalo except if otherwise mentioned.

Translation by Hannu Mononen.