I have just made several PCBs for a large project using the photoresist method. (I ran the boards through sodium silicate developer then through ferric choride) I then rinsed off all chemicals and dried the boards.

I believe there is some chemical electronic stores sell (conformal coating? I don't know) that would protect the circuit board from any sort of corrosion (which can include introduction of open circuits).

I know the next steps are to drill holes and solder components in, but after that process is complete, how long can I leave the board like that before it is absolutely necessary to add some sort of protective coating to it?

I want my board to last forever but at the same time, I don't want it to corrode (or have traces break up) as the years go by.

  • \$\begingroup\$ Protection counters hazards. What are the hazards? \$\endgroup\$
    – Whit3rd
    Aug 25, 2018 at 5:06

1 Answer 1


It will last as long as you keep condensation away from it or other solvents. Ionic solutions are what degrade metals, so the easiest way would be to keep it from those things.

That being said, feel free to apply your own soldermask

Polyurethane (humiiseal) also may go a long way toward keeping moisture out.

enter image description here
Source: https://learn.adafruit.com/how-to-solder-mask-pcbs/overview

Make sure you either, mask the metal you still want to solder to before applying the soldermask. And conformal coatings will coat everything and make for hard reworking and should be applied after assembly.

  • \$\begingroup\$ So I guess I should go with a "conformal coating" then? I looked at the adafruit page and it mentioned about poking the holes for any boards that feature through-hole design and my boards have on average 500 holes each. \$\endgroup\$ Aug 25, 2018 at 23:09
  • \$\begingroup\$ Usually they develop masks for the silkscreen. A conformal coating is done after assembly and will coat any metal. Please participate in the community, vote and upvote answers as this is why people take time out of their day to answer them \$\endgroup\$
    – Voltage Spike
    Aug 25, 2018 at 23:16

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