Thank you for affirming my contentions. I will never go back to FeCl
even if I run out of A.P.
Once the solution is spent, I dump it into a 5 gallon pail in my garage
and let it evaporate into dry crystals. It takes many dozens of gallons
of old solution to fill a plastic quart jar of crystals. I then wait for
our county landfill "hazardous waste disposal day" and take it there for
disposal.
Rick
http://www.pic101.com/pcbPhil wrote:
> There was a bit of discussion about AP a while ago and now that I
> have had about a month of experience with it, I thought I'd report
> back.
>
> I had a number of misgivings about AP based on comments posted here
> but since I had bought it, I figured I'd use it...
>
> My set up. A vertical tank that holds 1 L, a heater that brings the
> temperature to 100F and a bubbler. All my boards have been double
> sided so there was lots of copper to etch.
>
> Issues that had been raised:
> - short shelf life of AP solution. I've been pouring it out of the
> tank and storing it in a glass jar. So far i have done 12 boards and
> it appears to be still quite potent after a month. The last board
> etched in about 13 minutes, just like the first one. I did have a
> huge crystal (Cu sulfate?) form in the bottom of storage jar. Kind
> of pretty.
> - toxicity/fumes. While I haven't been making cocktails with it, I
> can say that I've experienced no problems or skin irritation.
> - cost. ya got me there, its about twice the cost of FeCl
>
> Some of the benefits of AP:
> - clear. I can easily monitor the progress of the etch.
> - non-staining. I spilled a little on a wooden benchtop and some
> paper. neither took more of a stain than water.
> - the powder is not exothermic when mixing with water. FeCl is
> really nasty that way. (I'm sure I'm using the incorrect term here,
> it releases a LOT of heat when mixed with water)
> - I believe it has more etching capacity than FeCl. I've done twice
> as many boards as with my last batch of FeCl (1 L, too). This is a
> subjective opinion and could be completely false...
> - pretty blue color
>
> If I had to get some new etchant today, I think I'd experiment with
> HCl+H2O2 but AP is a fine etchant to use and I'm very happy with it.
>
>