OT - Black engraving inlay
Made some aluminum Christmas ornaments for a friend with engraved inscriptions.
I used black Krylon in the engraving for contrast, followed with clear powder coat.
Problem: the dried paint out-gassed when curing the powder coat, causing bubbles.
I was able to rework the areas but am looking for a better way next time.
I recall a rather inert black coloring used in gunsmithing that might be more suitable, although a search of Brownells.com revealed nothing.
Any insight or recommendations?
Merry Christmas wishes to all.
I don't know if this would work in your application, but in traditional clockmaking, engraved dials are made of brass and silvered. The envgraved numerals and details are filled with engravers' wax (by gently heating the work and allowing the wax to "melt in", the excess removed by gentle scraping with a card and then gone over with a fine grit paper). The finished dial is sealed with a clear lacquer. The wax can be purchased from TimeSavers, as Black Dial Wax (part 18948), the url is http://www.timesavers.com/catalogmai...roductID=18948.
I think you are talking about a gun finish called Gunkote... it is a spray on then baked on finish.
If baking is an acceptable part of the process, perhaps genuine black japanning from Liberty Paint Co. in Hudson, NY would suit you. - JRR
Gun shops probably sell Birchwood Casey Aluminum Black, a chemical like gun blue.
Engraving suppliers sell a similar material. I have seen it on eBay, for a rather high price.
Engravers also use colored hard wax to fill narrow/deep lines. It does not work on wide/shallow lines and does not stand up to handling. Ornaments should be OK. The wax came in various colors. It was about the same stuff as crayons, but bigger sticks, so I would just use ordinary crayons or artists' wax pastels. Lumber marking crayons are a bit harder, and would probably be better. I rub it well into the lines, getting it warm in the process. Then I rub off the excess with a hard cloth like an old bed sheet.
Jewelers also use colored epoxy to simulate glass enamel without heat, which would melt aluminum. That process is more permanent than wax.
This web site sells Engravocolor sticks for filling.
You might try grill/stove paint or exhaust header/engine enamel paint. I would paint, then heat the object to somewhat above the powder coat cure temp, or whatever the paint maker recommends. Then do the powder coat.
The stuff used by artists doing metal engravings is called Engravers' Ground. It's available from most art supply stores (once you know what to ask for!). I use it to darken the engraving in the brass nameplates that I make up for my musical instruments. I'm not sure what the exact composition is, but it looks about like black coffee. You lightly brush it over the engraving, let it dry for a half hour, then gently scrub the surface with Scotchbrite. The black stuff stays down in 0.005" deep engraving quite well. I believe it's also available in colors other than black.
Brownells sells lacquer-stik. Comes in red, white, black and gold.
Here's what I did on an adjustable cheekpiece.
Bob, the inert stuff that gunsmiths use is a powder called bone black, used to mark the wood when you inlet the metal. Don't know how that would work in your case.
I used generic rustoleum enamel when I was redoing the plates on my Monarch. Dont use spray, use a can. There are more solvents in spray to make it thinner.
I only went to about 250 to 300 degrees though. I dont know how it will handle powder coat temps.
Originally Posted by Bruce Johnson
Do you have a manufacturer name for "Engravers' Ground"? I searched the web sites for many crafts stores as well as a web search and cannot find anything by that name. It may be my lack of computer skill but I'd like to try that stuff if I can find it.
With my failing eyes and old tools I want to try to darken the markings on my micrometers and calipers so I can see them again. I've tried paint and it just comes off (which is no doubt user error) when I try to get the excess paint off.
A good online resource for artist's supplies is Dick Blick Art Supplies http://www.dickblick.com/
I had the product name slightly wrong; it's called Etching Ground. Here's the link for the exact product I have:
It looks about like coffee (liquid, in the cup). Wipe down the metal part with acetone or lacquer thinner to get it free of oils. Then dab the Etching Ground on with a Q-tip, and let it dry for maybe 15 minutes. Then lightly wipe over it with some white Scotchbrite to take the excess off the surface. It dries hard in a few hours. It may take several applications, but usually one is enough. I use it on engraved brass nameplates that I make up, and it's simpler and better than anything else I've tried.
Thank you Sir! I'll give 'er a try.
About the toughest black you can put on aluminum is anodize. I have made lots of nameplates with black anodized aluminum coated with Kodak Photo Resist. You expose the resist with UV light, blocking the places where you want it to come off. Wash it off with a xylene solvent and etch, anodize, plate, or whatever in the unprotected areas. The attached pics are of a black anodized piece with the copy etched and a copper plate with the background etched back and gold plated. The copy comes through as almost black, but in real life, it is copper colored. You can strip the KPR off and heat the piece to darken the copper or use one of the blackening solutions.
For some reason the pics didn't take.