Is it a good idea/safe for circuit board components to be submerged in hot glue, in order to essentially "weatherproof" them to a certain degree? I don't believe the components will have the capacity to heat up enough to melt the glue.

It's a voltmeter and will be powered by a 9 V battery.

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  • \$\begingroup\$ Hot glue doesn't adhere too well to smooth surfaces like PCBs. Consider using epoxy instead. \$\endgroup\$ Jan 25, 2023 at 23:08
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    \$\begingroup\$ It's certainly not dangerous for the circuits - I believe "hot glue" is really just a kind of plastic with a relatively low melting point. It doesn't conduct electricity and your voltmeter certainly won't get hot enough to melt it (unless you really screw up). Whether it will prevent water getting in, I don't know. \$\endgroup\$
    – user253751
    Jan 25, 2023 at 23:09
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    \$\begingroup\$ Things that we think of as waterproof may not be quite so waterproof as we hoped. We might end up building a trap for water vapour. Whatever you use to encase the board must be water and vapour proof, and stick to the board really well. I'm not sure hotmelt is designed for that, though it may work. It might be better to use something specified for the job, a conformal coating, or a 'potting' epoxy or mastic. \$\endgroup\$
    – Neil_UK
    Jan 26, 2023 at 6:12

1 Answer 1


Hot glue could potentially remelt with hot components. Use a potting material or epoxy that is moisture resistant or waterproof. Another thing you might want to consider is a conformal coating (which help electronics to be moisture resistant if that's what you desire).


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