Until now, i have used fingernail dotting tools to draw traces with fingernail paint. Its the only thing besides photoresist that holds up to warm copper chloride etch at a pH of near zero.
Found something better. Old blood thinner syringes. Underneath the plastic safety stuff is a glass syringe. I removed the sharp part with a dremel and poured a few drops of nail paint in the back end without letting it run to the tip, then put plunger in and held it pointy end up and revoved the air. It tolerates being set down without plugging, but it could easily be put tip down into a sacraficial cup of paint to keep the tip fron clogging.
The board copper looks terrible because I abandoned it mid etch. One of those times an amazon resist pen failed me. This is my first attempt so I think I can make it look better with practice.
Found something better. Old blood thinner syringes. Underneath the plastic safety stuff is a glass syringe. I removed the sharp part with a dremel and poured a few drops of nail paint in the back end without letting it run to the tip, then put plunger in and held it pointy end up and revoved the air. It tolerates being set down without plugging, but it could easily be put tip down into a sacraficial cup of paint to keep the tip fron clogging.
The board copper looks terrible because I abandoned it mid etch. One of those times an amazon resist pen failed me. This is my first attempt so I think I can make it look better with practice.
Last edited:
