Intro: DIY Etch Tank
In this instructable I am going to show you step by step how I made my own etch tank for doing my own PCB's. I use the etching solution I saw here on Instructables mixing the muriatic acid with hydrogen peroxide. It has a greenish tint because I added the little bit of ferric chloride I had left to it.
- Plexi-glass ( 1/4"- 1/2")
- PVC pipe ( 1/2" I.D)
- PVC shut-off valve
- PVC elbow
- Small aquarium pump
- Plastic tubing for aquarium pump
- End cap for PVC pipe
- Super glue
- Water resistant siliconelectrical tape or duct tape
- Styro-foam or wood
Step 1: Prepping Materials
Cut the plexi-glass to the size you want to make your tank. Make sure you cut the sides the same outside diameter as the PVC. The PVC is going to be the bottom of the tank so it HAS to be a tight fit! I chose to keep my tank relitivly small because I never etch PCB's more than 5 inches square anyway. Once you have the 2 sides and the front & back done cut your PVC pipe to length, I cut my PVC 3/4" longer than the tank length to fit into the shut off valve then the valve should sit right on the edge of the side of your tank.
Step 2: Prepping Materials
At the bottoms of the front & backs of the plexi-glass I had to round out a little spot where the end cap and the shut off valve sits. Because it is larger diameter than the PVC itself we will need to round it out. Be patient when doing this it is just doing a little bit and checking to make a tight fit all along the bottom of the tank. I temp fitted the end cap and valve on just to check the notch was done right and the PVC sat nice and tight along the front and back of the glass. Also round the bottoms of the sides where they will sit on the PVC. These must be rounded to ensure a tight seal.
Step 3: Prepping Materials
Drill 1/16" holes along the PVC pipe spacing the holes 1 1/2" - 2" apart. this is for the air bubbles. You can stagger the holes or make them in a straight line. Then you can go ahead and put the end cap on.
Step 4: Assembling the Tank
When you have everything all prepped, go ahead and start fitting it all together. I super glued the PVC into the grooves in the front & back panels, then glue the sides in place. With the front still off you can go ahead and silicone everything you can inside and out. Once you have it all siliconed and it looks good, Super glue the hell out of the spots where the front piece will sit now fit the front piece of plexi-glass on. Letting the glue sit for a minute or two, silicone the rest of the tank. I know you're probley saying " What about the inside of the front panel"? It can't be done because the tank is to thin, but truthfully I havent had a leak, as long as your glue job has been done right and you do a nice, consistant job with the silicone it will be just fine!
Step 5: Supports
Now after I have it all together I took coloured electrical tape and taped around the sides of the tank as you can see in the pictures. Now this can be done with duct tape and really you don't even have to do it, I just thought it would add a little stregth to the over all design.
Next I made some supports for the tank...FEET! I just cut some styro-foam into rectangular pieces and notched them in the center half way down the thickness of the tank. I also went crazy with the electrical tape on them as well. But it is neccessary to add stregnth to the feet because the styro-foam is brittle and will break. Adding tape beef's them right up though! Now the tank will be able to stand upright.
Step 6: Retro Fitting the Hose
Now from the plastic elbow that connects to the shut off valve, the inside diameter is a little larger usually than the aquarium hose attched to the pump. I just added a little tape to the hose untilI could fit it into the elbow tightly. I let my tank sit for 24 hrs. to make sure the silicone had a chance to dry and set. The next day try it out with water to see if you have any leaks. If you are anything like me you over do everything (silicone, glue, tape, etc.) and not find a leak the first time trying. Now your tank is ready to use!
Step 7: Completed DIY Etch Tank
Now you have a great working printed circut board etch tank. Having the bubbles makes a huge difference in the time it takes to etch a PCB. You can also add a small aquarium heater if you want too!
Step 8: Drainage
I always drain my etching solution after use and keep it stored away out of reach where there can't be an accident with it! As clumsy as I am I just know leaving it sitting on my work bench in the tank I'm just asking to wear it! The elbow I installed is there for a reason and having fit nice and tight there was no need for it to be glued in so, I remove the elbow (making sure the valve is closed) and drain the tank into a tupperware container where I cant put it where it can't be spilled. I would recommend this to everyone who wants to make an etch tank.