On 02/03/17 17:28, Larry Battraw lbattraw@... [Homebrew_PCBs] wrote:
<http://www.ebay.com/itm/100g-Photoresist-Anti-etching-Blue-Paint-for-DIY-PCB-Photo-Etched-PE-NEW-/301857576850?hash=item46481d1792:g:Lt4AAOSwX~dWkyy~>
What do you use for the thinner?
I used all my commercial dry-film resist a couple of months ago.
It was atleast 10 years old, and i only stored it at room temperature in
a dark case.
I got problems with the stuff not developing off easily, as if UV was
getting through the black ink or something.
I found that by using 12g/Lt of Na2CO3 developer instead of 10g/Lt, all
the problems went away and the unexposed resist would wash off easily.
I also found that just using a much lower concentration of NaOH stripper
also works well as a developer.
>...
> I've eventually come to the conclusion that the cheap and...
> easily-obtainable negative brush-on photo-resist from China ($9
> including shipping to the US for 100g of concentrated resist that
> provides 300g when properly diluted, which is a ton of photoresist!) is
> the way to go. I use an Epson inkjet with cheap and easy refillable
<http://www.ebay.com/itm/100g-Photoresist-Anti-etching-Blue-Paint-for-DIY-PCB-Photo-Etched-PE-NEW-/301857576850?hash=item46481d1792:g:Lt4AAOSwX~dWkyy~>
What do you use for the thinner?
I used all my commercial dry-film resist a couple of months ago.
It was atleast 10 years old, and i only stored it at room temperature in
a dark case.
I got problems with the stuff not developing off easily, as if UV was
getting through the black ink or something.
I found that by using 12g/Lt of Na2CO3 developer instead of 10g/Lt, all
the problems went away and the unexposed resist would wash off easily.
I also found that just using a much lower concentration of NaOH stripper
also works well as a developer.