Homebrew PCBs

If you use lacquer based paint it will cure in 24 hrs or less and you can
take it or enamels off with lacquer thinner, will not affect the brass.


  -----Original Message-----
  From: Homebrew_PCBs@yahoogroups.com
[mailto:Homebrew_PCBs@yahoogroups.com]On Behalf Of fenrir_co
  Sent: Monday, January 29, 2007 11:14 PM
  To: Homebrew_PCBs@yahoogroups.com
  Subject: [Homebrew_PCBs] brass etching [was Re: New paper to test: Xerox
Waterproof]


  --- In Homebrew_PCBs@yahoogroups.com, DJ Delorie <dj@...> wrote:
  >
  >
  > "fenrir_co" <fenrir@...> writes:
  > > since I etch brass sheet and not PCBs
  >
  > Could you elaborate on this a bit? I'm thinking of etching my own
  > solder paste stensils for my next project.
  >

  I etch through brass sheet (hobby stores carry 4" x 1" sheets) in
  .005" and .010" thickness. I've done .016" and .032" but it takes WAY
  too long and there's massive amount of undercutting.

  Usually I only transfer to one side and spray paint the other side
  with oil based (not acrylic/latex) paint from a can (specifically,
  Rust Oleun's cheaper 'Painter's Touch'). Red makes a good contrast
  against the brass to see how well the etching is going. I suspend the
  brass sheet face down in a tray of etchant using a sheet of acrylic
  with 'feet' and slide-in runners made of more acrylic superglued onto
  it so I don't have to do any taping or such to hold it up. With fresh
  etchant the .005" takes about an hour, hour and a half, double the
  time then take a little off for the thicker ones. Once it's done I use
  a little bit of acetone which makes the paint bubble, let it dry just
  a little and you can lift it right off.

  Don't spraypaint until 2 days before you plan on etching. Earlier than
  that and the paint won't be dry underneath. Longer than a few weeks,
  the paint will be difficult to remove.



  


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