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Wondering if super glue could be safely used on a PCB to cover exposed traces or jumper wires.

I know it’s non conductive but is there any type of damage that could occur?

I normally use green solder mask that cures with UV light but ran out and need to finish a repair using jumper wires that need to be insulated

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    \$\begingroup\$ yes, but it doesn't take much heat for it to then evaporate & it gives of hydrogen cyanide \$\endgroup\$ – JonRB Oct 14 '17 at 0:33
  • \$\begingroup\$ Do they make green finger nail polish? \$\endgroup\$ – Michael Karas Oct 14 '17 at 1:19
  • \$\begingroup\$ Where is the board going? Into a product? What kind of product? Do any of the traces carry considerable power, or are they higher voltages (like 12V or more)? \$\endgroup\$ – mkeith Oct 14 '17 at 2:21
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    \$\begingroup\$ @user140123. Try urethane (polyurethane?) sealer, the type that is sold for floor coverings. Before anyone laughs, many years ago I used this as a manufacturer of product on circuits which involved both 12volt DC & 500 volt DC pulses at about 10kHz square wave. The urethane completely coated the populated board after soldering by heating said board & total immersion in urethane. It lasted "in the field" reliably in harsh thermal and vibration conditions for many years. Urethane can take high pulses at high volts without degrading over time, as my rash young "empirical research" showed \$\endgroup\$ – Stan H Oct 14 '17 at 11:28
  • \$\begingroup\$ @user140123. And if it's a question of, will the said urethane sealer degrade circuit operation at radio frequencies, the answer is no, by the same inadvertent longterm aspect of my "empirical research". In this case I did not heat treat the populated MHF transceiver PCB and immerse the entire board (had to leave the L and C adjustments free). I would spray the track side of the PCB only with red urethane sealer. // In defence I must say I responsibly researched the properties of urethane "inhouse" before releasing anything to the mercies of customers' wallets \$\endgroup\$ – Stan H Oct 14 '17 at 11:40
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The primary purpose of soldermask is to prevent solder from going where you don't want it to go. I'm sure you're well aware of this. The problem is that the solder burns right through superglue with no trouble at all, and the vapors are nasty. If you breathe it in it could cause respiratory issues, and if you get the vapors in your eyes they will burn for hours (I speak from experience). I strongly recommend staying away from using superglue as soldermask. Take the time you need to order and receive new soldermask. It will be well worth the wait.

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  • \$\begingroup\$ I would solder first and apply super glue after just as an insulated cover to exposed wires. Would there still be an issue like that? \$\endgroup\$ – user140123 Oct 14 '17 at 1:31
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    \$\begingroup\$ @user140123 The circuit should be reasonably safe even when subjected to failures. If something goes wrong with your circuit and a component overheats to the point where the superglue begins evaporating, you are in serious trouble! If it is for hobby work, then it isn't worth the risk. If it is for professional work, this solution is not going to be conforming to any sane safety legislation and you risk being sued (or worse-IANAL) if something goes horribly wrong (even if it is only a prototype). \$\endgroup\$ – Lorenzo Donati supports Monica Oct 14 '17 at 5:08
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For the purpose as you describe it, you need just to cover your exposed traces and re-work. This is not a "solder mask". The best and standard way is to use "conformal coating", found in electronics stores. It comes in several different flavors, acrylic, silicone, urethane, etc. Any type will serve your purpose well and much better than the super glue.

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Crayola makes easy to use non-toxic biodegradable food safe solder mask in a variety of colors. You can find it in the toy section at most stores. I have used it for masking when wave soldering. It works great and easily comes off with a little elbow grease.

Superglue, as has been mentioned can give off toxic, potentially fatal, fumes when heated.

enter image description here

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    \$\begingroup\$ And it includes a sharpener, too! \$\endgroup\$ – jonk Oct 14 '17 at 4:03
  • \$\begingroup\$ I don't get why the paraffin wouldn't just melt away in a solder bath; and even if the residue still resists a bit, the melted wax going everywhere would put 'resist' in places where you don't want it \$\endgroup\$ – Nick T Oct 15 '17 at 1:30
  • \$\begingroup\$ Well, in wave soldering, the solder bath is only in contact for a moment. The surface may melt slightly, but it won't completely vaporize. \$\endgroup\$ – Anthony Bachler Oct 15 '17 at 6:47
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It seems you are confusing the function of solder resists as being some form of electrical insulation rather than being a mask that prevents solder going where it shouldn't.

Although not particularly conductive, solder resist should in no way be relied upon as an electrical insulator, especially when insulation is required for safety reasons. The integrity of the resist is simply not integral enough to be relied upon to not have cracks and holes in it, especially after soldering. Further, it chips off easily.

The layer is also very thin and will not withstand much voltage across it.

There are other, better, materials specifically designed for this purpose if you really need electrical insulation.

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