Homebrew PCBs

"awakephd" <a_wake@...> writes:

> The patterns have two inner blocks and traces of the designated size
> and spacing spiraling outward to two outer blocks.

I have bigger patterns like this here: http://www.delorie.com/pcb/spirals/

> Now for some questions: 1) The PC board turned a chocolate brown
> color after heating on the hot plate.

Hot plates keep getting hotter and hotter.  I found that I *can't* use
the hotplate for a second board unless I let it cool completely first,
else the board burns (charred epoxy!).