I have a small PCB, about the size of a quarter and having a Bluetooth chip on it. I have 4 wires soldered to the board. 2 of which are for a 3.7 Volt battery connection and 2 are to connect a small loudspeaker.

All of my components (PCB, battery, loudspeaker) are going to be encased in a cloth band and worn on a persons ankle. I am worried that through repetitive movement, my soldered connections will get disconnected.

Is there a recommendation for further protecting the soldered connections. I feel like wrapping it in electric tape won't be enough. Is there some kind of latex coating I can use to either coat the soldered connections or even the entire board?

I've heard of conformal coating. Is that my solution? If so which type for my case?

  • \$\begingroup\$ Instead of using a conformal coating, I'd encapsulate it using a soft urethane or silicone encapsulant, and for the wires I'd use something like this and strain-relieve them where they exit the pooky. \$\endgroup\$
    – EM Fields
    Mar 11, 2015 at 6:31
  • 2
    \$\begingroup\$ How about putting the whole thing inside heat-shrink sleeving? \$\endgroup\$
    – Majenko
    Mar 11, 2015 at 11:02
  • \$\begingroup\$ Both are great options. The heat-shrink sleeve sounds less messy. Where can I find sleeves of different sizes? Mine needs to be about 3cm in width. \$\endgroup\$
    – Jet59black
    Mar 11, 2015 at 12:41
  • \$\begingroup\$ @EMFields do you think I can encapsulate the entire PCB (except for the on/off switch on the side of the PCB of course)? \$\endgroup\$
    – Jet59black
    Mar 11, 2015 at 23:02
  • 1
    \$\begingroup\$ @Majenko any thoughts on where to find heat shrink sleeves for PCBs? \$\endgroup\$
    – Jet59black
    Mar 11, 2015 at 23:03

1 Answer 1


I've found that hot-melt glue makes a great board coating. Cheap, very easy to use, no solvents involved, sets up in minutes instead of days, excellent electricals.

  • \$\begingroup\$ If rework is needed it's also very easy to remove using denatured alcohol. Just swab the area with 90+% alcohol, wait a minute or two and the glue peels right off. It's otherwise nigh impossible to remove. \$\endgroup\$ Oct 25, 2019 at 10:37

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