Homebrew PCBs

> > I made a really great looking toner transfer. When I etched it in 
a spray 
> > tank (standard chemicals not FeCl) several traces got slowly 
sprayed 
> > away. It seemed as if the traces might have been weekly bonded 
and the 
> > spray just washed them away over 1 or 2 minutes. Is this usual?
> > John
> 
> 
> i assume you have cleaned the board well?
> 
> maybe the mechanical force from spraying is too much for the toner.
> what are the "standard chemicals" exactly?
> 
> did you use a iron or a laminator?
> which printer model/ toner manufacturer did you use?
Good questions; I'll add a few more:

Board cleaning is probably the biggest buggabo; sometimes you can get 
good adjacent toner bonding and mask over a small fingerprint smudge 
or some other contamination.

What temperature are your "standard chemicals" etching at?  The 
combination of heat and spray pressure might be too high for a weakly 
bonded toner resist.  (If the board is cleaned properly the TT bonds 
are generally pretty good --also a bit of work getting off after 
etching!)  

How fine are the traces that are disappearing?  

What oz. clad are you using?  Although I haven't had much 
undercutting using 1 oz - .5 oz and a FeCl agitated bath; even with 8-
10mil traces (if you are watching it closely!).

I haven't seen the need for this with the laminator, but some have 
suggested "cooking" the newly formed resist layer for a bit in an 
oven to allow the toner reflow and bond better to the board. 

If you are using a laminator and cut the board down to size before 
etching; did you clean/sand the scored edges?  These can lead to 
local eruptions along the cut edge and create just enough of a valley 
on the board that the image will get uneven pressure through the 
laminator.