So I'm making up some dextin and using toner transfer to make up a board.
You roll your own dextrin paper?! Wow!
I'd never heard of that working reliably, I'm inspired to go looking for better instructions now.
I'm trying something new actually. Instead of paper I'm using dextrin coated tinfoil. It didn't turn out so good tonight, but I think its because the laser printer I used doesn't put much toner down. I might try photocopying it at staples tomorrow and see if that will put more toner down.
My basic process is
Make dextrin: about 1/4 cup corn starch cooked 1.5 hours at 400 deg C mix every 20 minutes. Don't over cook, that reduces the water solubility of it as much as under cooking. It should be golden yellow.
Coat tinfoil. Using a disposable pneumatic sprayer coat the dull side of the tinfoil with a dextin solution. I cut mine with rubbing alcohol which probably isn't great. The mixture separates quickly, next time I probably will just use water. Put a few coat on the aluminum.
Cut up the foil and tape it at the top to a piece of paper.
Print!
Laminate: Press onto copper that has been roughed with steel wool and acetone.
Let this cool for a bit.
Soak in water with a little soap in it for 1/2 an hour - 1 hour.
Etch with ferric chloride, clean with more acetone.
Presto, perfect traces (in theory).
My goal is to get 8 mil spaces and traces.