CircuitWorks Overcoat Pens

You should be able to unclog by 1) removing the cap, 2) let it sit tip-down in a solvent like isopropyl alcohol, 3) press down (without squeezing the barrel) a few times in the process to break the stopper loose, 4) let sit 5-10 minutes, 5) then when you take it out, squeeze the barrel and try to write.

Black (CW3300BLACK) and White (CW3300WHITE) are also available to repair PCB markings or cover component identification for security or IP protection.

CircuitWorks Clear Overcoat Pen (part #CW3300C) is available to patch areas on more unusually colored resist coating (e.g. brown, purple, etc.).

No. CircuitWorks Overcoat Pens should be the final step in processing the board. The Overcoat material is a modified acrylic conformal coating not an epoxy resist material, so it does not have the same properties of durability and permanence as a permanent solder resist. It will decompose at temperatures above 270°F (132°C), and therefore should only be applied to the board after all soldering has been done. When soldering is required after the repair has been done, Chemtronics offers CircuitWorks Epoxy Overcoat (CW2500). It is a permanent green coating formulated to protect circuit traces before being exposed to reflow conditions. Epoxy Overcoat two component, 100% solids epoxy that is engineered specifically for high temperature resistance, used for electronic circuit and component protection.

Chemtronics offers CircuitWorks Overcoat Pens in a variety of colors to match the PCB resist. Overcoat pens are basically acrylic conformal coating in convenient packaging, and the clear version can be used to coat small areas. Simply press down the pen tip and squeeze the barrel to dispense the coating material. 

Printed circuit boards (PCB) come in a variety of colors, including green, blue, red, brown, and even purple. The most common is green, but that can vary by application, industry, and the age of the PCB. Fashions change over time, and so do common PCB colors. Today, green is the most common. The reason? Not for any significant performance difference. Arguable, some colors may be easier on the eyes when assembling, soldering and reworking electronics, or work better with inspection optics. In reality, the main reason is probably price. Whatever is most common color will generally have lower cost, because bareboard suppliers are running that color continuously. Any odd color will require a change-over, extra clean-up, and thus additional cost.

The shelf life of a product can be found on either the technical data sheet (TDS), available on the product page, or by looking on the certificate on conformance (COC). The COC can be downloaded by going to https://www.chemtronics.com/coc. Once you have the shelf life, you will need to add it to the manufacture date for a use-by date. The manufacture date can be identified by the batch number. The batch code used on most of our products are manufacture dates in the Julian Date format. The format is YYDDD, where YY = year, DDD = day. For example, 19200 translates to the 200th day of 2019, or July 19, 2019. This webpage explains and provides charts to help interpret our batch numbers: https://www.chemtronics.com/batch-codes.