electrolysis rust removal

[Raya]

Included in a box of bits I came across, were most of the parts from an early 1948 AD. The cylinder was in poor condition being completely blocked with rust and there was a crack around one of the securing bolts that probably occured during the dismantling.

The rust was rock hard and wouldn't easily scrape out so decided that, with nothing to lose, I'd try the reverse electrolysis method to remove the rust. I had tried this method previously on an old steel fuel tank, and it kinda worked, but the tank was more rust than steel so not a total success.

After one night in the tank, the head looked a mess, but the rust was loosened up considerable. I scraped out what I could and gave the head another night of treatment. The rest of the rust came out easily with a bit of poking and water blasting. As this was an early model, access to the inside passages was helped by the removable welsh plugs. The water jacket passages were given a rinse with phosphoric acid to finish with. I used some "steel weld" compound to repair the crack so maybe all is not lost with this motor and it may yet live again.

Here are some before and after pics of the cylinder.

[Charles uk]

This could be the cylinder that belonged to your D.

[Raya]

Alas no, this cylinder is off AD4233, a 1948 outboard. It has the slotted welsh plugs instead of the hex plugs that the D would have. I could use it on the D but will keep it together with it's crankcase for originality. I have the matching gearbox and prop so will assemble this one after the D. I'm developing a liking for the early 102's. They just seem to grow on you.