Oxidation/drip from deck post-cap lamp (stained glass)
I very recently purchased 6 stained-glass post-cap lamps from Amazon. They looked great at first (see the final four pictures on this page, but after the first rain, the “lead” began oxidizing and turning whitish.
This morning I noticed that the oxidate was dripping from the lamp edges onto the handrail below it. I realize this is a wood, not metalworking, forum, but I just wondered whether anyone would have an idea of what kind of solder-able compound metal would produce this kind of rapid oxidation, and whether there were any way to prevent/remove it. I imagine that I could have stopped it by spraying the lamps when new with a can of clear spray lacquer, but that ship has already left the dock. I’m going to revise my review on Amazon and contact the state-side manufacturer (the lamps are actually made, as you might expect, in China).
Replies
Hokuto,
I think what you are seeing is the result of acid rain. Google "stained glass- acid rain". I would clean them up with sme baking soda, rinse and spray with a automotive clear coat.
Nice work by the way!
KK
Pure lead doesn't seem to oxidise that quckly, but most likely you aren't looking at pure anything if it's from China - it's whatever the cheapest metal is that will look close when it's new.
There are clear-coat products made for such uses - I'd look at one of the big stained glass suppliers like Delphi (I think?), but it will probably be a product such as an oil based poly that is wiped on after the oxidation is cleaned off.
Thanks much for the suggestions. After posting I did some looking around on stained-glass sites, and some comments seemed to suggest that this kind of whitening is par for the course for this stage of lead oxidation; I don't understand the science behind it, but one person suggested that lead oxidizes in stages, and this white powdery stage is normal for early oxidation. Apparently the color will darken with age--or so that person said. I may try a toothbrush with baking powder on a small area just to see what happens; I'll also be looking at the stained glass section of Tokyu Hands when I get some time free in Tokyo.
Thanks again.