Homebrew PCBs

On 01/06/2009, at 2:57 PM, DJ Delorie wrote:
> To those who use TT without TRF: comments on how well toner alone
> blocks etchant? Do you get pinholes in the copper?
>
Just getting back to this - I get a few holes in the toner in larger  
areas, but never actual holes through the copper. I am just fooling  
with this and running ridiculously low on toner anyway, but I've  
certainly never had a trace actually interrupted by a toner hole - I  
do keep them as wide as practicable, plenty of 16mil ones, don't think  
I've gone thinner.

(I did some unofficial Delorie spirals at 6mil, but I've yet to hand- 
iron them evenly enough to bother etching)

PG