Etsning

[Carrot]

Håller på att exprimentera med att etsa mönster i metall och ramlade över ett "recept" som kanske fler kan ha glädje av...


Materials:
Table Salt
Water
Plastic Container
Car Battery Charger
An automotive light bulb
A Scrap of metal
Etch Resist (See Notes)

Setup:

Fill the plastic container with warm water and 1TBSP of salt per pint of water. Stir until the salt is disolved.

Place a plate of scrap metal into the salt water (the electrode).

Attach this plate to the negative terminal of the car battery charger (this connection should be above the water line).

Attach the positive terminal of the charger to one of the connection to the car light bulb.

Attach a wire from the other connection of the car light bulb to the piece to be etched.

Immerse it as well into the salt water solution.

Bubbles will begin to form around the electrode and the light bulb may or may not light.

Periodicaly pull the piece to be etched from the water and check your progress and wipe the oxides from the surface.

It would appear that there is a relationship between the speed of the etch and the voltage by the way. I've tried the process with as many as three car batteries in series.

For general etching purposes however a 10 amp battery charger seems to be more than adequate.

I've not found any need to remove the oxides from the etched piece except in the case of very deep etchings, and there a bit of strong vinegar on a rag was enough to accomplish the task...

Etch resist:
It seems that plain, simple, cheap car autobody primer works really well to cover the backs of pieces and large areas that I don't want etched. you can scratch through the primer to apply your desired pattern, but I've found that photosensitive circuitboard etch resist works very well in this process too! So all I do is spray the area to be etched with the etch resist and let it dry. Then I print out a negative image of what I want etched on an overhead projector transparency. This is then loosely taped over the piece and it is set in the sun for a while. Then there is a developer solution that removes the unexposed resist (follow the directions for your particular resist/developer combination). Then I etch the piece. This process means that I can duplicate etching patters across multiple pieces. You can get the resist/developer for about $15 from electronic supply houses and the overhead transparency sheets can be gotten from any good office supply store.

Tips and tricks:
When you have finished etching your piece of metal in this way, you can put a copper piece on the other electrod, and swap the + and the -. In this way you will fill the scratches with native copper (red) that can be variously colored with some jewelry solutions (from blue to brown ecc.)

[Eric Hejdström]

Du får gärna skriva och berätta hur det gick när försöket är fullföljt! Jag har funderingar på att etsa mina blivande rustningsprylar...

[Carrot]

Har hunnit testa en gång nu och är nöjd med resultatet.

Det verkar som om man måste vara väldigt noggrann med att täcka det som inte ska etsas, men det var ingen större överaskning. Jag använde mig av slarvigt påstruket nagellack...

På ca 2 timmar blev etsningen ca 0,5 mm djup, så det gick snabbare än jag trott.

Jag har aldrig använt syra för att etsa, så jag har inte så mycket att jämföra med egentligen.

[Eric Hejdström]

Det verkar som om det bet ganska så djupt ganska fort. Jobbar man med plåt till rustningar och liknande så har man ju inte så tjockt matrial. Asfalt är annars ett väldigt smidigt ämne att täcka med när man skall etsa, nackdelen är att man måste nästan ha thinner om man skall få bort det. Hittade ett annat "recept" i min rustningsbok som jag funderade på att prova också. Får se vad tiden tillåter...