I accidentally damaged a gunmetal casting (an end plate of the condenser unit) of my triple expansion engine. I considered soldering a piece of brass or gunmetal and filing it to shape, but decided instead to try one of the 2 part epoxy repair kits. There are plenty of these with iron/steel coloured material, but for a long time I could not find a copper coloured repair kit.
The damaged, machined casting. I have punched some indentations to increase the adhesion of the filler, then washed it in acetone to remove all traces of grease.
Then I spotted this epoxy repair kit at an Aldi supermarket. So I decided to give it a try. Cost $AUD5
DYNASTEEL, Copper Repair. And this initial blob applied to the defect.
An hour later, after some paring with a knife and filing.
Next day, after some more sanding. Appearance not too bad. More shaping of the casting is intended. The epoxy repair is meant to tolerate temperatures up to 200 c. If it proves unsatisfactory I will solder in a patch.