Although I have not tried it myself, It was suggested to me that for
best results a layer of uniform thickness is essential.
So to accomplish this place the PCB flat and with two strips strips
of brass shim place them on the board along two opposite edges and
then spray the board. Now with a glass tube or suitable rod gently
roll this along the board with its ends bearing on the shim. This
should roll an even thickness of resist equal to the thickness of the
shim.
Note - I have not tried this, so there may be unforseen problems, I
realise the glass would pick up some of the resist behind it, so
maybe more than one rollover is necessary. Anyway it may be worth a
try, unless someone warns against it from experience.
What are you spraying the board with, the Electrolube product or is
there another product available?
Electrolube also sell a developer for their product, a bit expensive
but it may be something special.
Does anyone know if their developer is necessary or will anything
else do?
Leon.
--- In Homebrew_PCBs@yahoogroups.com, "crankorgan" <john@k...> wrote:
>
> 1.Clean board
> 2.Shake can before each use.(What I did not do the first few times)
>
> (in the dark with safe light)
> 3.Tilt board upright on 45 degree angle
> 4.Spray from right to left working your way to the bottom
> 5.Blot off excess that runs to the bottom of board
> 6.Lay board flat to dry. (I used an old hair drier to
> dry the board.)
>
> I found I need more exposure time than the instructions in order
> to get a good trace.