Before you begin etching anything, there are a couple of things you should know about the chemicals involved. Read on to learn more about two of them: hydrogen peroxide and ferric chloride.
HYDROGEN PEROXIDE
While it might seem innocuous, hydrogen peroxide (in the bottle) is actually pretty dangerous stuff – 35% solution can cause severe burns if accidentally ingested or if allowed to come into contact with eyes. While not as potent as chlorine bleach, keep this chemical away from your skin and only use it in a well-ventilated area. You may want to wear gloves when handling it. When used for etching, its strength will be diluted down to 1% solution so its danger level down quite a bit but it can still cause irritation if it comes into contact with skin.
FERRIC CHLORIDE
Ferric chloride is not as dangerous as hydrogen peroxide but that doesn’t mean it’s without hazards. It emits some pretty noxious fumes that you don’t want to be breathing in for any extended period of time – the vapors will irritate your sinuses and lungs. Keep your head out of your etch tank! Also, make sure you are wearing gloves when handling this chemical – the same goes for hydrogen peroxide too. It is also a very potent acid so be careful where you store it. Never mix ferric chloride with hydrochloric or sulfuric acids – there may be violent reactions among these chemicals.
SAFETY TIPS
One last thing to remember when you’re etching with these chemicals; work in a well ventilated area, wear gloves and protect your eyes. These chemicals will irritate the skin and damage the eyes so handle them with care! And of course, don’t ingest or inhale these chemicals either. Ferric chloride is also known to eat away at certain types of rubber so inspect your gloves and silicone molds for signs of wear before using them.
MASKING TAPE
One trick that I learned from my years as a DIY blogger is how to un-stain metal surfaces that have been stained by masking tape – just brush on hydrogen peroxide and watch the stain disappear! Just apply it with a clean brush and wash off with some water.
ETCHING THE METAL SURFACE
Now that you know all about the chemicals, it’s time to get down to the business of etching your metal surface! Your work area should already be free of contaminants – if not, give it a good wipe-down before you get started. Use some steel wool or sandpaper to roughen up your metal surface then rinse with water. This will remove any protective oils left over from machining so your paint will stick properly. Let dry completely before moving on.
To get your design etched onto the metal, use either a light table, copy paper or printing transparency film pressed against the surface of your design. The light table is by far the best way to go but it is not essential.
PAINTING THE DESIGN
If using a light table, place your metal sheet on top of it then tape down your transparency or printout with masking tape. If using printing film, just tape it down to the metal surface without taping over any of your design – this will help keep paint from bleeding under the edges. After taping down your design, make sure everything’s lined up where you want before brushing on some designs.