Instructables

Make your own bubble etch tank

video Make your own bubble etch tank
Make your own bubble etch tank for less than £20. Using a Ferrero Rocher chocolate box, aquarium pump and heater.
kjchowdhry1 year ago
Great instructable! Very practical and easy to follow.
pfred21 year ago
Wow you really got involved with your etching tank! You can see my setup in this article:

http://www.instructables.com/id/GM-Arts-Overdrive-Pedal-Build/

I use the container in a hot water bath method. Sort of a bain-marie. For an air pump I used one of those lousy 12 volt tire air compressors. Open, with no pressure being held, they put out a nice pulsing air supply that I find agitates my etch tank rather well. Find one in the trunk of an abandoned car. The lousier it is the better. The connecting rod in mine actually broke so I had to replace it with a nail. Quality stuff!

My air inlet is a tire valve I took the valve out of, then stuck a rubber hose on, that goes to a smaller hose, and finally into a spray cap from an aerosol can. The acid ate out the middle of that, but it still seems to work OK to me. I suppose someone could just cut the air chuck off of the air compressor too. I have a bunch of tire valves so I went that route.

For my etch tank I used a black plastic container microwaveable frozen entrees come in. My water bath is a casserole dish I picked up at a thrift store. I put some smooth pebbles on the bottom of it so my plastic etch tank doesn't rest right on the bottom of the casserole dish. Under the water bath is an electric grill I found at my town dumps. I suppose any hot plate type of thing would work. A George Foreman grill, whatever they have at a thrift store that plugs in and gets hot. Maybe a coffee maker with a hot plate for the carafe?

I monitor my temperature using a meat thermometer I keep in a test tube filled with plain water. But I don't think it is that important, once the acid starts fuming I can turn my grill off and the whole setup maintains temperature long enough to etch a board. I mean if you can see fumes you don't need a thermometer to look at too. Yeah the fumes can make your nose a little itchy. Probably best not to breath them in too deeply. Heck I bet if someone was blind they could smell when the tank was ready. It does have a distinctive smell to it when it is set.

Hot tip: Ferric Chloride works the best at about 105F when it begins to fume a little for me. Basically when you see some fumes coming off your acid you're good, maintain that temperature.

When my acid is good, not all loaded up with copper, I can do an etch in about 2 minutes. I consider anything past 5 minutes problems.

I only do one sided boards because I don't want to plate through holes, or try to solder on the component side of a board. So I etch copper side down in my horizontal tank. I guess if I did double sided boards I'd have to look into one of these vertical setups.