Electrolysis on cylinders

[marc.h.]

Does anyone have any luck cleaning up cast iron cylinders from vintage Johnson’s A35 K45 ect…) I am trying to de rust the cooling space of the cylinder and wondered if it would have an adverse effect on the finished cylinder walls..
Any other treatment recommendations for the treatment of rust in the cooling chamber??
Thanks
Marc H

[wbeaton]

Electrolysis works in line of sight. It’s not going to do much inside a water jacket. You may find more success with a product like Evaporust or Metal Rescue.

Coincidentally, Evaporust helped unseize this late 1920’s Evinrude RBM powerhead today. Two days soaking and then a couple heat treatments with penetrating oil is all it took. Admittedly, it wasn’t too rusty inside. Keep in mind this photo is after the Evaporust bath.

Wayne
Upper Canada Chapter

uccaomci.com

• This reply was modified 4 years, 4 months ago by wbeaton.
• This reply was modified 4 years, 4 months ago by wbeaton.

[need2fish]

I’ve had a lot of luck with CLR — it’s just high-powered lactic acid. I’m not happy with what it does to chrome, aluminum and some painted surfaces, but it’s worked well for getting stuff of the water jacket walls.. If you immerse the powerhead in CLR, it may leave a layer of black oxide on the bores which can be wiped off and sluiced away with PB Blaster. It’ll also discolor (gray) pistons.

Picking at the line-of-sight can work as some of the bigger flakes head for the water outlook and create a log jam.

Copper colored steel BBs or similar sized bearing balls and shaking the cr-p out of the powerhead is another treatment. Make sure they don’t get into the external pipes and that they are smaller than inlet, outlet and corners in the jacket.

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