I have a cast iron bridge lamp project that includes dealing with some rust. I have a couple of the modern chemical treatments that I could use but got to wondering what would have been the A&C period approach to removing or inhibiting rust? Any thoughts?
I have restored many iron pieces including "bridge Lamps" by removing the rustic with a wire brush, then treatingte iron with mineral oil. The oil dries and one would never know anything was done to it and the rust doesn't come back.
I would assume during the period they would have treated the iron with oil although not sure if it would have been mineral oil. But I have absolutely no eveidence for it.
Yes I was thinking mineral oil. I've used it on tools as a rust inhibitor. Mineral oil is a petroleum byproduct so I assume they had it in the A&C years (because they had kerosene and gasoline) and would have been experimenting with uses.
Some time ago I posted a desk chair restoration where I had to remove rust from the reclining/swivel mechanism. I used a modern gel rust remover and I didn't want it to look new so I just rubbed it all with standard 5W30 motor oil! Mineral oil is probably more authentic but the real problem with either option is that the oil tends to collect a little dust. Once you give it a few days, it doesn't feel oily.
I'm going to try a lamp black stove polish that I just found - seems to essentially be a water soluable wax. I'll post the completed job including shade when done.
- rewired and new plug - new internal socket with 2 way dimmer but saved the original brass casing (original switch was broken) - 'lamp black' stove polish over the whole frame, but not sure if I like this - colour and finish is great but it does not dry to a hard wax type finish, in other words it leaves 'dirty hands' when you grab it - new spike top ferrule made from a copper pipe cap and an old spelter ferrule from a parts box shade - parts box brass fitter added to the socket - shade salvaged from a ceiling fixture - very rippley (real word?) slag; a couple cracks repaired with gel krazy glue
I've treated similar projects by wire-brushing the rusted areas using lemon oil (Formby's or similar) and wiping clean with a rag. It requires multiple treatments, but it usually results in a very slight greenish patina (much lighter than a "verdigris" color would be) yet still more appealing than plain naked gray cast iron or black steel. I avoid using any water during the cleaning because the scrubbed surface tends to reoxidize quickly once the existing surface has been roughened.
I'm curious Stonecat, as to what rust removal method you ended up using on your above bridge lamp? Was it one of the suggestions? Or did you opt to just leave any of the rust?
I've got an old iron bridge lamp that I've been meaning to get around to working on (one of several things on my seemingly endless list of restoration projects in the works or needing to do). The state in which I acquired it, the iron was painted black at some point in the past (probably a quick and dirty fix it to make it look uniform and new). Underneath the black paint (which I did a test removal of with some paint stripper) is rust of course. I'm unsure how I want to approach the rust layer, since I want to leave some kind of antique patina look to keep it from appearing brand new.
Did the black stove polish you were initially unhappy with ever dry to a harder finish, or is it still a little oily after many weeks?
I just brushed off and wiped down the surface rust with a stiff plastic brush (to avoid scratches) and mineral spirits (to also get grunge). The stove polish seems to have hardened up pretty good but if you really rub it a bit comes off - obviously much better than before however. The rust seems to be in check - I can't see any coming through.
Looking at some of the stove polishes, it appears they are meant to be cured by heat. Maybe that's the reason why it stayed a bit oily?
Has anybody used/seen the product called Tool Black from Precision Brand? Looks like it might do the job better.
I've stripped the paint off the iron and scrubbed it with mineral oil and a scotchpad to try to cut back the rust. It looks much better, but still needs to be blackened/colored I think.