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anyone build an etching tank? i was thinking about building one with the same heater and pump that this guy uses-
http://eegeek.net/content/view/45/31/

i think i'm going to try and find a better tank though. maybe some kind of skinny fish tank? ant farm? anybody have any experience?

i have one , i never use it, they're kind of a pain and not the cleanest but i havent used it in about 5years so maybe ill give it a second chance.

I had one - it was a hassle to use
I use a pyrex dish and heat it over my gas range stove top with a gentle swishing motion to promote a clean etch - works fine
bajaman

bajaman wrote:I had one - it was a hassle to use
I use a pyrex dish and heat it over my gas range stove top with a gentle swishing motion to promote a clean etch - works fine
bajaman

With which etchant?

ammonium persulphate of course
bajaman

Thanks, so you reach the same temperature (115 °F) approx? What's your aapprox etching time then? I really have to try this etchant...

I guess I would use a pyrex dish too, but I'm interested in the heater...

I just heat it until just below boiling point - takes about 5 to 10 minutes depending on the board size etc.
If it gets too hot I move it from the flame.
Cheers
bajaman

what was the hassle exactly?

The problems I had with the one I tested at work were:

- loosing a PCB down the tank while taking it off the etchant to see it (it was ferric perchloride in it)...

- having a good enough bubbling to make the etching homogenic (the top of the PCB is harder to remove than the very bottom).

- the filling and emptying of the tank always led to bad stains on my boiler suit...

Here's my experience... But I did thought about making one too, probably more easy to use...

Btw I've read that ammonium persulphate is degrading itself if you overheat it (say 50°C), and also that it lets ammoniac in the air permanently, even more when bubbled... God! There's no clean etchant really...

I use HCl+H2O2 with an inexpensive commercial etching tank and it etches an 11cm x 15cm board in under 3 minutes with fresh chemicals. I do it in the barn because the fumes are dangerous... a nose-full of HCl fumes is not a good time.

The heating and agitation are the key components. HCl+H2O2 is a good etchant, but if it's cold and sitting stagnant, it's just as slow as anything else. I think if you can get something decent put together with a heater and bubbler, the other factors become less important.

bajaman wrote:I had one - it was a hassle to use
I use a pyrex dish and heat it over my gas range stove top with a gentle swishing motion to promote a clean etch - works fine
bajaman

I do the same thing except I set the etching dish in another dish of water, kind of a double boiler thing. I just stir it around w/ a wooden skewer.

RnFR wrote:anyone build an etching tank? i was thinking about building one with the same heater and pump that this guy uses-
http://eegeek.net/content/view/45/31/

i think i'm going to try and find a better tank though. maybe some kind of skinny fish tank? ant farm? anybody have any experience?

How about this: http://www.circuitspecialists.com/prod.itml/icOid/4232

I used to use one till my 4 year old spilled it all over the floor and her. At least it wasn't heated up at the time.

theehman wrote:

bajaman wrote:I had one - it was a hassle to use
I use a pyrex dish and heat it over my gas range stove top with a gentle swishing motion to promote a clean etch - works fine
bajaman

I do the same thing except I set the etching dish in another dish of water, kind of a double boiler thing. I just stir it around w/ a wooden skewer.

yeah, I was doing this until I dropped my coke bottle of FeCl all over our stainless steel benchtop

I now have a larger plastic bin (low-ish profile - maybe 10cm?) that I do the lot inside (kind of a self enclosed workspace). it has the coke bottle of FeCl and the two takeaway plastic trays inside it. one tray is larger, has recently boiled water and a sponge (to stabilise the inner tray).
I can pour the etchant into the smaller takeaway tray and then from the container back to the coke bottle after, all within the 'safety' of my larger plastic bin. then the lid goes on coke bottle, and bin sits (with a lid on) under a speaker in the lounge till next time.

looks a lil like this


with these inside