My new etching tank

Thread Starter


Joined Jan 17, 2007
As for matherials for my improvised eching tank with heater and agitator, I used 5mm acryl and sealed with hot glue, no kidding. :D It wasnt very pretty, but it did the job, two years later with loads of ferric chloride or sodium persulfate in it - still in use and not one leak. :)
Nice... post a pic!


Joined Nov 27, 2006
C @cmartinez
A while ago you wanted to know about etching times for sodium persulfate. Tonight I etched five, 4" X 6" boards. I mixed 2 Kg of sodium persulfate in 2 liters of tap water. The tank temperature was just below 50 Deg C. I etched the boards one at a time. The first three boards were complete in 22 minutes and the fifth board was complete in 31 minutes. (Times include pulling the boards in and out of the tank.) The etchant still had plenty of capability. I put the last board (5th) into the tank, took the fourth board into the bathroom to wash it off, picked up another beer, and by the time I got back to the bench the fifth board was half done.

I used Ferrichloride for a long time, then I met a guy who had a business making PCBs on commercial scale. He told me to not use FeCl3, but rather HCl diluted 1:2 or 1:1 with water. Then add a little Copper sulfate to add copper to the solution for starting the process easier. The colour should be blueish green. When the solution turns dark, just add a dash of Hydrogen peroxide (as strong as you can get). It will make the solution clear again. This is a nice, clean etching solution and I shall never revert back to FeCl3. After the mixing process, it produces no fumes.
Just my penny's worth! (Remember to add acid to the water and not the other way round!).
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Joined Apr 5, 2008

In holland we say "water bij zuur geeft vuur".
It will say, adding water to acid will give fire.
The acid will become very hot when adding water.



Joined Aug 24, 2012
As I said before, it ain't pretty, but does the job. Long tubing is for FeCl3 fish tank compressor for agitation, not used when etching with sodium persulfate. I think I redo it better some day, as my friend works at acrylic shop now and have capability to make stuff there cleaner and better.