Hi folks

I need etch out piece of enamel because the customer don´t like the particular color. I cannot grind it out so I need etching solution.

I know there is kind of hobby etching paste but this is very slow, I tried it.

I have hydroflouric acid but I don´t like that idea to use it. How this acid react with 18K gold?, I know I need safety equipment and good ventilated area. I just want to know how this acid react with metals? How long it takes to etch 2x2cm enamel 1mm deep?

 

Thanks for any advice

 

Rudolf

HF doesn't attack gold but will attack the 25% non-gold content to some extent. Copper, silver and palladium are etched slowly.

I never tried etching enamel with HF (don't want that at home), but from past work experience I'd say about a micrometer per minute for phosphosilicate glass in buffered HF (usually 1:7 with NH4F) at room temperature. But then it depends on the kind of glass and the way it is deposited, if it is annealed, ... . You can also try 10:1 HF but the etch rate decreases over time.

 

 

So, I did the etching with HF. Not worth the danger. Transparent goldgreen Schauer enamel approx 1x1cm, 0,4mm deep cell after 4 hours not etched completly.Acid bite the glass and form milky substance that stop the etching. It need to be washed off and new fresh drop of acid used. For me better use Etchall glass, much more less hazardous and the same result.

Hi Rudolph, do you know a source for Etchall Glass in Europe. It is difficult - if possible at all - to have it shipped from the US

regards Gisela