Jewelry Making - Engraving With Nitric Acid
Nitric Acid is extremely toxic and dangerous to use.
This is well documented elsewhere.
Ferric chloride is a much safer alternative but nitric acid is extremely fast.
You need: Masks, glasses and thick protective gloves 2 plastic buckets, baking soda, plastic tongs Beeswax, aluminum foil (optional), white spirits Preparation of jewelry: Use beeswax only.
The easiest method is to melt the wax and paint the piece with 2 coats using a small brush.
This can give a bumpy surface, so requires extra care when carving the design into the wax, and care in cleaning leftover wax residue.
However, you can get a nice thick uniform coat, by shaping a piece of aluminum foil, into a mold, to the size of the jewelry.
Pour in the melted wax, then the metal, and allow it to cool.
Peel off the aluminum.
The aluminum method has the advantage of making the wax easier to draw on and cut.
If the wax layer is 2 millimeters thick, then entire chunks can be cut out, leaving no residue on the metal, and requiring no further cleaning.
The thinner the wax coat, as in the two coats method, the more likely the wax will need to be scraped off, leaving behind some residue.
If there is residue, soak a cotton wool bud in some white spirit solution and clean off.
If you do not clean off, even small amounts of residue will affect the ability of the acid to corrode and the end appearance of the engraving.
In addition, I find a thick 2 millimeter wax layer gives better definition and sharpness, particularly to geometric patterns, corners and edges.
Nitric Acid works great with brass and copper, not so well with nickel silver/alloy.
Prepare your Nitric Acid Bath: Nitric acid is not worth organizing for individual pieces, because it is too toxic.
Instead, minimize your usage and exposure by doing lots of jewelry pieces at once.
I use it perhaps 3 times a year.
Set up your acid bath outdoors.
I would never use it indoors.
Ensure no pets or strays have access.
It only takes around 15-25 minutes to etch, so keep an eye on the bath at all times.
Do not use thin metals, otherwise they will burn through.
Wear gloves, masks and glasses at all times.
Use a plastic bucket for the acid bath.
The usual ratio is 1:1, nitric acid to water, for metals like brass and copper.
The nitric ratio is much weaker for silver.
If no fizzing occurs after a few minutes, add a little more acid.
Use the plastic tongs to check the pieces, but keep this minimal because picking them up, damages the wax and can ruin the design.
Place the pieces next to each other, not on top of each other, this also damages the wax.
Dilute some baking soda in a bucket of water nearby.
Once etched, transfer the jewelry to the solution of soda/water.
Then rub each piece further with dry baking soda.
Rinse with clear water and dry.
Disposing of Nitric Acid: Do not pour down the sink or toilet.
Neutralize the acid bath by pouring in some baking soda.
Eventually it stops fizzing and is neutralized.
I then pour the neutralized solution in the garden, followed by lots of water.
This is well documented elsewhere.
Ferric chloride is a much safer alternative but nitric acid is extremely fast.
You need: Masks, glasses and thick protective gloves 2 plastic buckets, baking soda, plastic tongs Beeswax, aluminum foil (optional), white spirits Preparation of jewelry: Use beeswax only.
The easiest method is to melt the wax and paint the piece with 2 coats using a small brush.
This can give a bumpy surface, so requires extra care when carving the design into the wax, and care in cleaning leftover wax residue.
However, you can get a nice thick uniform coat, by shaping a piece of aluminum foil, into a mold, to the size of the jewelry.
Pour in the melted wax, then the metal, and allow it to cool.
Peel off the aluminum.
The aluminum method has the advantage of making the wax easier to draw on and cut.
If the wax layer is 2 millimeters thick, then entire chunks can be cut out, leaving no residue on the metal, and requiring no further cleaning.
The thinner the wax coat, as in the two coats method, the more likely the wax will need to be scraped off, leaving behind some residue.
If there is residue, soak a cotton wool bud in some white spirit solution and clean off.
If you do not clean off, even small amounts of residue will affect the ability of the acid to corrode and the end appearance of the engraving.
In addition, I find a thick 2 millimeter wax layer gives better definition and sharpness, particularly to geometric patterns, corners and edges.
Nitric Acid works great with brass and copper, not so well with nickel silver/alloy.
Prepare your Nitric Acid Bath: Nitric acid is not worth organizing for individual pieces, because it is too toxic.
Instead, minimize your usage and exposure by doing lots of jewelry pieces at once.
I use it perhaps 3 times a year.
Set up your acid bath outdoors.
I would never use it indoors.
Ensure no pets or strays have access.
It only takes around 15-25 minutes to etch, so keep an eye on the bath at all times.
Do not use thin metals, otherwise they will burn through.
Wear gloves, masks and glasses at all times.
Use a plastic bucket for the acid bath.
The usual ratio is 1:1, nitric acid to water, for metals like brass and copper.
The nitric ratio is much weaker for silver.
If no fizzing occurs after a few minutes, add a little more acid.
Use the plastic tongs to check the pieces, but keep this minimal because picking them up, damages the wax and can ruin the design.
Place the pieces next to each other, not on top of each other, this also damages the wax.
Dilute some baking soda in a bucket of water nearby.
Once etched, transfer the jewelry to the solution of soda/water.
Then rub each piece further with dry baking soda.
Rinse with clear water and dry.
Disposing of Nitric Acid: Do not pour down the sink or toilet.
Neutralize the acid bath by pouring in some baking soda.
Eventually it stops fizzing and is neutralized.
I then pour the neutralized solution in the garden, followed by lots of water.
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