,Photoresist Anti-etching Blue Paint
2013-10-26 by Kerry Koppert
I purchased some of this stuff off ebay some time ago and I've just got round to testing it. First up I had to find a thinner (what the seller calls diluent) the suggestion was Banana Oil. I tried to source some banana oil (Amyl Acetate) in New Zealand to no avail (I used to buy it as a kid 50 -60 years ago for model aeroplanes) but I tracked down some Pentyl Acetate but the supplier was out of stock. He suggested Ethyl Acetate, N-Butyl Acetate or ISO Propyl Alcohol so I got some Ethyl Acetate. It doesn't smell as nice as Banana Oil but it works. Next I tried painting a board with a brush. It sorta worked but the covering was uneven so I pulled out my El Cheapo Air Brush and tried that. Hey it works and give a pretty impressive result. I do have one problem. If the coating it too thick the developer doesn't remove all the exposed area photoresist, however judicious use of caustic soda solution and cotton buds fixed this.