This is a reasonably large compressor electric motor which I wish to restore. It has an ancient capacitor in, and some darling little oil cups on the bearings.
I surmise the central barrel is something ferrous, while the end bells are an alloy or aluminium. The paint is suffering all over the place from rust or alloy corrosion depending on the underlying metal, and I'm guessing the dissimilar metals have made it worse than it might otherwise be.
I intend to clean the alloy sections with non-woven abrasive pads and hot water. You can see one section at the top left of the end-bell, and one on the top of the pulley wheel where I've tested about 20 seconds of dry rubbing with a green abrasive pad. The loose paint and surface white corrosion has come off quite easily. I intend to avoid a wire brush on the alloy bits lest flecks of dissimilar metals get embedded. However, there are sections of adhered paint - maybe a scraper on the flat bits if that wouldn't damage the alloy, or perhaps the good old heat gun on the rounded awkward bits...?
The ferrous bit will be wire brushed or attacked with a similar pad in an angle grinder (after disassembly).
When it's done, I was thinking the two metals ought to be separated more than they were to avoid galvanic action in the damp Cornish climate, and certainly painted with different things initially to prime the awkward metals. For finishing, I am keen on linseed paints (I know it was OK for preserving hardware in Scandinavia through their harsh weathers, and some people use it instead of Waxoyl) and am leaning towards some Kreidezeit 'stand oil' paint - particularly the gold which I've had good results with on a welder. An alternative I've thought of would be something like the enamels from Paragon Paints.
I wanted to know if anyone had ideas of 'best practice' for a hardwearing and reliable finish that won't encourage the swift encroachment of fresh corrosion, or hints on preparation and treatment of the dissimilar metals. The alloy control box was so crusty the two buttons were stuck and I had to punch them out from the back! I guess being bolted to a big ferrous tank and frame wasn't helping. The white, powdery corrosion doesn't seem to be particularly well attached so does scrub off leaving superficially undamaged metal behind.
I surmise the central barrel is something ferrous, while the end bells are an alloy or aluminium. The paint is suffering all over the place from rust or alloy corrosion depending on the underlying metal, and I'm guessing the dissimilar metals have made it worse than it might otherwise be.
I intend to clean the alloy sections with non-woven abrasive pads and hot water. You can see one section at the top left of the end-bell, and one on the top of the pulley wheel where I've tested about 20 seconds of dry rubbing with a green abrasive pad. The loose paint and surface white corrosion has come off quite easily. I intend to avoid a wire brush on the alloy bits lest flecks of dissimilar metals get embedded. However, there are sections of adhered paint - maybe a scraper on the flat bits if that wouldn't damage the alloy, or perhaps the good old heat gun on the rounded awkward bits...?
The ferrous bit will be wire brushed or attacked with a similar pad in an angle grinder (after disassembly).
When it's done, I was thinking the two metals ought to be separated more than they were to avoid galvanic action in the damp Cornish climate, and certainly painted with different things initially to prime the awkward metals. For finishing, I am keen on linseed paints (I know it was OK for preserving hardware in Scandinavia through their harsh weathers, and some people use it instead of Waxoyl) and am leaning towards some Kreidezeit 'stand oil' paint - particularly the gold which I've had good results with on a welder. An alternative I've thought of would be something like the enamels from Paragon Paints.
I wanted to know if anyone had ideas of 'best practice' for a hardwearing and reliable finish that won't encourage the swift encroachment of fresh corrosion, or hints on preparation and treatment of the dissimilar metals. The alloy control box was so crusty the two buttons were stuck and I had to punch them out from the back! I guess being bolted to a big ferrous tank and frame wasn't helping. The white, powdery corrosion doesn't seem to be particularly well attached so does scrub off leaving superficially undamaged metal behind.