I have two pieces of enameled fine silver which haven’t worked ( I forgot to clear enamel first, and the colours changed). How can I get rid of the enamel to reuse or melt down the silver?
Use the search function (magnifying glass icon) on the upper right corner to search on “Re: Remelting gold with enameling on it?” then scroll down to the reply from Pam East.
I did something like that years ago and it worked well, but I don’t remember what I used. The materials Pam East suggests are by far the least dangerous chemicals I’ve seen mentioned to remove enamel.
Just to make it easy to access, here’s an answer that was posted quite awhile ago, and it is based on Pam East’s method for removing enamel from your metal. I’ve used it a number of times and it works perfectly. " Mix equal parts of Salt and Cream of Tartar…now take some water
and make it into a creamy paste. Place this mixture all over your
enameled piece. Heat your piece in the kiln at 1425 or so for 2-4
minutes. Take your piece out of the kiln (don’t worry…the piece
will be black…this is normal) and immediately drop it into a
container of ice water. Use a steel brush to remove all enamel."
You can remove enamel from fine silver or even cast sterling that has been depletion
“silvered” (frequently called “gilding” which is the term for gold.)
Hydrofluoric acid will dissolve the enamel without hurting the fine silver or the “silvered” sterling.
Just remember that hydrogen florde is MASSIVELY dangerous. Be careful and have a big bottle of Milk of Magnesia on hand for accidents.
Hydrofluoric acid should not be suggested on Orchid when someone who does not know how to remove enamel asks how, and has a reasonable expectation that the instructions are safe as well as effective. This poster made absolutely no mention of how dangerous the recommendation is, and even the reply by rc2 is lacking.
Wikipedia has a section on the dangers of hydrofluoric acid anyone can look up. Here’s what the CDC has to say about it:
Immediate signs and symptoms of exposure to hydrogen fluoride
- Swallowing only a small amount of highly concentrated hydrogen fluoride will affect major internal organs and may be fatal.
- Hydrogen fluoride gas, even at low levels, can irritate the eyes, nose, and respiratory tract. Breathing in hydrogen fluoride at high levels or in combination with skin contact can cause death from an irregular heartbeat or from fluid buildup in the lungs.
- Even small splashes of high-concentration hydrogen fluoride products on the skin can be fatal. Skin contact with hydrogen fluoride may not cause immediate pain or visible skin damage(signs of exposure).
- Often, patients exposed to low concentrations of hydrogen fluoride on the skin do not show effects or experience pain immediately. And, severe pain at the exposure site may be the only symptom for several hours. Visible damage may not appear until 12 to 24 hours after the exposure.
- Depending on the concentration of the chemical and the length of time of exposure, skin contact with hydrogen fluoride may cause severe pain at the point of contact; a rash; and deep, slow-healing burns. Severe pain can occur even if no burns can be seen.
Long-term health effects of acute exposure to hydrogen fluoride
- People who survive after being severely injured by breathing in hydrogen fluoride may suffer lingering chronic lung disease.
- Skin damage caused by concentrated hydrogen fluoride may take a long time to heal and may result in severe scarring.
- Fingertip injuries from hydrogen fluoride may result in persistent pain, bone loss, and injury to the nail bed.
- Eye exposure to hydrogen fluoride may cause prolonged or permanent visual defects, blindness, or total destruction of the eye.
- Swallowing hydrogen fluoride can damage the esophagus and stomach. The damage may progress for several weeks, resulting in gradual and lingering narrowing of the esophagus.
Here’s a quote from Bruce Holmgrain on Orchid, Subject: Accident rate 1/10/1998:
“I got a drop next to my fingernal. I couldn’t wash it off or
neutralize it. Went and saw a doctor. He put my hand in a
whirlpool and acted pretty much like I was some kind of sissy
trying to get a day off of work I repeated to him what the
precautions on the bottle said. There was no visible damage.
Seems that most damage was done where new fingernail was beimg formed. My nail fell off inside of a week.”
Suggesting the use of hydrofluoric acid without mentioning the dangers is reckless. Using it without access to a ‘moon suit’ is nuts. This kind of a suggestion doesn’t belong here.
What I suggested was the solution to the problem. Of course protective gear and proper ventilation is essential for working with acids.
I just Googled “how to remove hard fired enamel from silver”. I was surprised to find
That there’s a YouTube video on using a product called “De-Enamel” a non toxic product. It didn’t exist when I was involved in enameling many years ago in a large factory.
I’ve used Pam East’s method as shared by Linda and it really does work. Expect the coated enamel piece to look like a burnt toasted marshmallow when it comes out of the kiln. Since I didn’t know what to expect, I filled an orange Home Depot work bucket half full with cold water, and donned a cotton apron, a face shield and ear protection. Although none of the glass shattered beyond the bucket when I dropped it in the water, it did make an explosive sound that made me jump.
If any glass remains you can repeat the process. It’s very quick and effective.
If your intent is to melt the silver into ingots to roll or draw, the simplest way to remove the enamel is with a hammer. It’s just glass, after all. Smash it up good, remember to wear protective eyewear and a breathing mask. What little is left can be removed with a stiff brass brush under water, you want as little glass dust in the air as possible. And wear gloves, kitchen scrub gloves are fine.
When you melt it use lots of borax and stir the melt well with a carbon rod or even a hardwood dowel, which will quickly become a carbon rod. Any residual enamel should float to the top as slag and be captured by the borax.
Niel, I’m with you on this acid. It’s the strongest acid out there. Beware it is stored in glass, enamel is glass. How could Hydro Fluoric acid eat the glass when it maintained most stability in glass? Use the other methods mentioned. Dont go buying or working with this EXTREMELY DANGEROUS acid.
Hydrofluoric acid is stored in Teflon bottles as it is one of the few acids that will attack glass. As well as other uses in industry, it is used to etch glass. Before the invention of plastics it was stored in paraffin vessels.
It is one of the most corrosive acids and poses many health risks.
The first enamel ring I ever made, I quenched in water after the last torch firing, ruining the piece.
I simply broke most of the enamel off with a hammer and then melted the remnants on a charcoal block, manipulating the melted silver ball with a pick. The glass adhered to the charcoal block and could be chipped off afterwards. Low tech method but it worked.