Blackening Lead Came

What are you doing now? Jet black look? OK, are you making your own cement, or using what? Bristle brush ? What are the bristles made with? I get a dark lead, jet black? sometimes I guess, never paid that much attention, let's say , really ,really dark pewter. Maybe its qualifies as black.

Make my own stuff, formula is well known,(some dislike it), final step is with Natural Bristle brush( not Nylon bristles) and buff like crazy, for a little while, the more you buff, the nicer it looks.

I am "going natural," which means doing nothing. As I said, I tried in the past with both nylon & bristle brushes. I recall reading that one studio suggested a certain TYPE of bristle brush, but can no longer recall what they said (it may have been an availability issue as they were from some other country).

Anyway, we make our own putty (3 parts whiting, one part plaster of paris; equal amounts of mineral spirits and boiled linseed oil, plus a cap of Japan Drier; Mortar tint is sprinkled in to make the brew to a black color).

I guess what I am really asking is what makes the came go black? Is there an interaction between the putty and came? Does the friction build up heat that chemically changes the surface of the lead, yielding the black look? What is going on??

The black I want is VERY black. I've seen it before but didn't realize then that I should have asked the artist how he got that appearance.

FYI, the reason I am suddenly caring is that I have a commission for an interior wall of art glass. Since there will be no direct sunlight coming through and (in essence) making my lead lines look black, I think the design would work better if the came had that look no matter the lighting.

--Cactus

I don't think you can get it jet black without paint or chemicals. If you want to work it with natural bristles, whiting, and lots of time, you can get it very dark gun metal gray. It reacts to the oxides in the natural bristles. Same as it does with the oxides on your skin.

The reason I said no chemical is two-fold: I think it would be messy and just as time-consuming to use a chemical. The chemical would likely not be even in its application (I am remembering my foil days when I would patina a panel and getting it overall the same was a chore). Second, I do not think the artist I saw at a trade show in New York in the early 1980's would have had access to the variety of chemicals that now exist. Since I have heard/read that the blackening can be had by buffing, I am hoping to gleam some tidbit that will improve my efforts.

Any one else out there with an opinion?

-Cactus.

in my distributor, i saw a round, natural bristle brush you can chuck up in your drill. looked like the ones in my parent's old floor waxer.

You might want to consider electroplating. It comes out looking pretty cool, a nice shiny black (or whatever colours they have available) finish that stays. If you do decide to give it a try, remember that you cannot use zinc framing and you cannot putty it until after your panel is plated as both these items will spoil the chemicals and they either won't accept the job or they don't want you coming back. I've had some done in black, dark brown, brass ("gold") and nickle ("chome") and was real pleased with the way it looked. Bart.

custom compensated banjo bridges, tabs, stained glass:

It's called a Pzazz Brush. Your local shop should be able to get one for you. You can also order replacement brushes for it. Works great!

Andy

If you want it really black, add about a 1/4 cup of lamp black to your putty/cement mix and then polish with a nice brush. Just my $0.02 worth.

!/4 cup amp black mixed with what volume of putty mix?

ML

That seems like a LOT of lampblack to me.

I mix/ store my putty's dry components in the large coffee cans, I probably only use a tablespoon or so of lampblack to probably 5 lbs of whiting/plaster.

I mean, how black IS black, anyway?

Sorry, it's added to a 1 Imp. gal. mix.

What is lamp black? Never heard this term before.

If I use Dap 33, can I do the same thing, or if there is a better way to make the white Dap 33 putty black?

Thanks

marc

Still way too much, when I mix dry ingredients, I use 2 cups carbon black per 75 lbs batch. and that is really black, in fact in order to make a medium grey, I have to add 4 to 1, white mix to black.

Whatever works for you tho.

Lamp black is also called carbon black.

Don't use Dap33. It won't adhere to the metal. Dap 1012 comes in a grey and can be used for puttying lead came. It isn't the "best" product for the purpose, but will work in a pinch.

Do you really find an appreciable difference in the 2 DAP products? I'm sure they must be formulated separately, but I don;t see it. I tend to use whichever one I can get, and see no reported difference after years outdoors.

I was going by what the CRL catalog says. DAP labels the 1012 as being for the SG craftsman, so I went with that idea. I was told (eons ago) that the "33" is for wood sashes, and that it wouldn't adhere to the metal. Other folks may have a different idea. Plus, the 33 only comes in white, AFAIK.

I only use the DAP when I have an onsite repair and I don't want to mess with making up a batch of the homebrew.

Put a cold spoon in the yellow part of a candle flame and lamp black will deposit on the spoon.

How does one actually make usable quantities, though? Or even buy it? I was fortunate enough to have a good friend send me a couple of zip-lock bags full of the stuff, otherwise, I wouldn't have any at all. I mean, I don't need a 55 gal drum of the stuff, but would like to have a source for it. Thought once about trying to pulverize a charcoal briquet, but didn't know if that would work.

When I was a mere youth I used to read a lot of chemistry books. I just remember the description of lampblack production as depositing the particles of a carbon flame on a cold surface. I suppose you could get a copper belt moving through a carbon flame with a scraper cleaning the deposit into a container. I seem to remember that was how they did it. Probably easier, cheaper, and cleaner to just buy it. Charcoal is pretty close but not as fine as the deposit would be. May work for coloring purposes though.

A google on lampblack is interesting at 12:47 Monday morning.