Etched Minty Valentines Candy Box

Step 4 Set up the etching station

WARNINGS:
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There are several important points to make here.

First, you must use a DC power supply. An AC supply will have little or no effect, no mater how strong. AC current stands for Alternating current. It means that there really is no "positive" electrode. The current in AC circuits alternates directions. The electrons will never flow consistently enough in one direction to transfer metal particles. The Mythbusters (US Discovery channel show..) actually demonstrated this theory in episode 26 "Salsa escape)
http://dsc.discovery.com/fansites/mythbusters/episode/episode_06.html
Jamie and Adam attempted to cut their way through prison bars using this method and salsa as the liquid. Adam used direct AC current from the wall, Jamie used DC from a smashed radio power supply. Adam's had no effect.. Jamie's bars were cut clean off.

Second, DO NOT plug in the power supply until everything is set up. plugging it in is the last step before etching starts.

Third. When testing the PC fan, don't accidentally put your finger in there and cut it like I did that one time.

Fourth. If you have cats, keep the cords up and tight. It will make a spectacular and dangerous mess when your cat grabs a wire and runs for it.... little sh**s...

Fifth. I should not have to say this, but I will. In no case under any circumstances at all ever should you run house (mains - for those of you overseas) current directly into the solution. it just won't work for one thing, and could very easily kill you.

Last, you are using electricity here. Please be careful.
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The basic idea of using electricity to plate or etch metal has been around for a long time. In fact, it has been the subject of several articles:

http://www.instructables.com/id/EKVI03SL4PEV2Z566X/

There was another one where a guy used the same process to cut a design into his PC case, but I can't find it right now...

It's essentially the same principle used to chrome or gold plate metal. You put the positive electrode on one metal, and the negative electrode on another. When you submerse them in a conductive liquid, like saturated salt water, the electrons will flow from one metal to the other, taking some of the metal with them. You will get the idea.

This is also (in principle) how throwing a radio in the tub will kill you. The electricity will flow from the radio, through YOU, to the metal drain in the tub. Mythbusters episode 19:
http://dsc.discovery.com/fansites/mythbusters/episode/00to49/episode_07.html

Take the plastic bowl and fill it with about 2-3 inches of lukewarm water. Slowly dissolve the salt into the water until it won't take any more. This is a saturated salt solution. You could use regular water without the salt, but it would require more electricity, and take far longer. The salt increases the conductivity of the water greatly.

For the process to work, the two metals should be close, but not touch in the water. I usually pinch the negative wire between the lid and base of the tin, then connect the positive electrode to the fan, and then to two lengths of copper wire wrapped around some bolts. Check the diagram and picture below. The bolts just help create more surface area. You could use the wire alone. I usually use two bolts. It spreads the effect out better. If you only used one electrode, try to get it centered under the piece. If it's off to one side, the etch could be uneven.

In this case, I have the bolts on the bottom of the pan, add the tin floating upside down in the water. It works just as well to flood the tin and have it submerged in the water.

Comments

[Hadokendude]

I had three questions: A) What do you use for a DC power supply? Like a computer power supply, or something different? B) In place of a power supply would a 9-volt battery work? and finally B) Is it imperative that I use a cooking bowl of some sort, or could a plastic disposable bowl work as well?

[imajem]

I once made a metal plater for jewelry with a 6/12 battery charger and a kitchen door spring and it worked like a charm....for the DC power.

[photozz]

A: Anything that puts out DC voltage. I have used PC power supplies and "Wall Wart" adapters. both work fine. B: Yes. A battery should work ok as long as the piece is not too large. The bigger the etch, the more power or time required. A few people have used batteries with good result. C: any plastic, non-metallic container would be good. Cheerio!

[aridese]

Electrolysis (etching) with table salt is an EXTREMELY DANGEROUS thing to do.

Table salt (sodium chloride) ionizes in water:
NaCl -> (Na+) + (Cl-)

The positive and negative electrodes gather Cl- and Na+ respectively. The positive electrode will make chlorine gas! I am confident you smelled a "pool" like odor when you performed this.

If you don't want to take my word for it, here is a site describing the process in greater detail:

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch20/faraday.php

In the quantities you are using, the amount of gas produced can be dangerous -- this is the same poison gas used in WWII. An alternative electrolyte you can try for electrolysis is sodium carbonate (washing soda) or sodium bicarbonate (baking soda) heated to 200C to produce sodium carbonate.

For the safety of others, please amend / remove this instructable...

[mxridercc]

Hahaha that website shows that the process requires molten NaCl not NaCl(aq). Hardly the same

[pharoah]

First, let me point out that Chlorine gas was only used at the beginning of World War ONE, it was replaced with more effective gases such as mustard gas. Second, if you perform this experiment in a well ventilated area you should be fine. I don't think anyone here would be stupid enough to stick their face above the etch bowl and inhale for a few minutes. Just exercise a bit of caution people.

[threecheersfornick]

If table salt ionizes in water... why doesn't the ocean create chlorine gas? Should I stop going to the beach? And, couldn't you just do this outside?

[finfan7]

has to have electricity.

[offlogic]

Aridese- Etching with saltwater is safe, ask someone who knows, like a teacher or art or chemistry. Better still, experience the hazard first hand: etch something. Then you can compare and contrast the sheer hazard vs. running with scissors (the pointy ones, especially) and using household ammonia cleaners (DEADLY GAS!!!!). Chlorine was used in WWI (notably at Ypres, Belgium in April 1915), but was considered more trouble than it was worth. That made it easy to get signatories to the 1925 Geneva protocols that banned the use of "poison gas".

[photozz]

**sigh... let's calm down here. this process may produce minute amounts of chlorine gas, but as has been discussed in the past the amount produced with a tabletop setup is to small to be noticed, much less approach dangerous levels. The level of chlorine gas coming off a swimming pool is many times more dense than what I can produce with 5volts in a mixing bowl of salt water. This has already been extensively covered farther down in the thread. No, the kitchen did not smell like a pool, and I had one etch running for over 6 hours. That being said, if you notice noxious green smoke or such, a certain amount of common sense should be applied as with any project on instruct ables.