Well, I tried diluting and airbrushing some of the ink (white) but didn't have any success.
Well, it dilutes ok. It airbrushes fine to a thin coating. And I "baked" it in the oven at 180 degrees C for about 20 minutes and it "dried" ok, soft but tack-free. Then I tried to cure it under the UV.
But... it doesn't seem to cure under the UV at all, something is inhibiting it, it can easily be scraped just by gently rubbing your finger nail on it or even just pressing your finger nail on it, there is no difference between masked area and exposed area. And meths on a cloth just wipes the board clean with no effort at all.
The alcohol I'm using is just Methlyated Spirits (>= 95% ethanol, and the rest water with a tiny amount of a bittering agent)
The UV cure I gave up at 30 minutes, no change in the hardness or fastness was particularly noticable, it was still "soft".
Hmm, I notice on the referenced site (
http://nicadrone.com/index.php?id_cms=24&controller=cms ):
"Dry the paint in a reflow oven, drying temperature influences exposure time drastically above 100C "
it doesn't say in which direction it influences, perhaps my drying temperature is too hot and this messes the exposure?
So in short it would be really great if Andreas (ctech) could give some brief details...
1. your board shows a soldermask (green) and a silkscreen (white), which paints exactly did you use for these? Just the ebay ones, one green and one white?
2. what type of alcohol did you use specifically, ethanol, isopropanol, methanol...?
3. what temperature and time did you "bake" the board at to dry it?
4. are you doing anything else before exposure?
5. how long as you exposing the board for to the UV under the mask?
6. what type of UV source are you using, and are you using any fancy things like a vacuum system?
7. how are you developing it after exposure exactly, with the same alcohol, with sodium hydroxide...?