> places for hanging board holders. I have some 1.25 inch, 80 psi
sewer
> pipe, which is black, not white. I don't know the chemistry. I
White sewer pipe is PVC plastic, the black stuff is ABS, butI don't
know anything about it's chemical reactivity.
> I got 2 gallons of hcl for $5 at home despot, and a quart of h2o2
for
> a buck at Savon. Now all I have to do is use the stuff.
I'm guessing, but is that Savon drug store? So this H2O2 is the 3%
medical grade?
> I've looked around some, and never seen any sites that say 'use 5
> parts hcl to 1 part h2o2 to 9 parts h2o', or whatever. Does anyone
know
> what the final % hcl and h2o2 the solution should start with? I've
seen
> how to keep the cucl2 going, but not how to start it right.
> Thanks,
> Richard
Others will reccomend using stronger H2O2, 30% or 50%. But I had a
hard time finding it without paying extremly high hazmat delivery
fees, so I experimented with using the weaker medical grade.
My acid (HLC, or Muratic) is bottled at 31 point something percent
strength. From what I've read you want between 10 and 15% in the
final etchant. Generaly that's accomplished by diluting the acid 50-
50 with water and then adding up to a couple ounces per gallon of 30%
H2O2.
I have successfully used 2 parts 3% medical H2O2 with one part 31%
acid - no additional water. It's pretty close to the same mix when
you're done. Etching times of 7-10 minutes.
With stronger H2O2 (30% or more) you can just add a little more to
regenerate the mix. With the 3% stuff it has too much water and if
you add enough to regenerate the CuCl it dilutes the mix to much. To
get around that I usualy just regenerate with a bubbler. (aquarium
pump and a plastic "air stone")
By the way, I use a rubbermaid 5161 ceareal keeper as an etch tank:
http://tinyurl.com/3hbax About $5.50 at Walmart, holds a gallon and a
half and can do a 9x9 inch board nicely. For a holder I usualy just
dangle them on a piece of plastic coated wire (cat5). Mostly just
loose loops around opposite corners, but sometimes I drill a hole in
the corner.
-Denny