1PCS Maintenance guy UV UV curing green oil marked blue photosensitive solder green oil and butter oil / board protection paint
Pen trace of corrosion, humidity. It is also satisfied for PCB repair after welding, rework.
length: Approx. 9-10 cm
apply the paint on the PCB.
spread on the PCB with coating the transparent film.
expose it to UV light (or sun) for a few minutes.
wash away the extra paint from petrol or solvent base oil.