Which glue to secure wires soldered into PTH holes?

[741]

For giving some mechanical strength to wires soldered directly into PTH holes on a PCB, what is a good material to give some mechanical support?

There is something called "non acidic silicone", would that be usable here?

I'm after something that won't degrade the PCB and it might be better if it were a firm 'rubbery' set rather than something hard like 2-part resin.

[PKTKS]

From the old days of THT only boards...

- Plastic straps using tht as well can do miracles...
- today i guess cheapest close thing is zip ties

Chemicals only make it bad

Paul

[voltsandjolts]

Expensive solution: RTV3145 (DOWSIL neutral cure RTV)

Cheaper solutions:
Hot melt glue
neutral cure RTV from aliexpress, e.g. 704
DOWSIL 799 neutral cure RTV from Screwfix
DOWSIL 738, 748 and others... but are harder to source at the moment

Avoid acetoxy type (vinegar smell) RTVs which give off corrosive acetic acid when curing.

[741]

OK Thanks.

I once read hot melt is slightly conductive. I can believe "Chemicals only make it bad" - also I wonder about moisture being trapped. However, the practice is used by major manufacturers

I have a PCB here salvaged from someone's refuse ( ). It's from a 'Sky Box'. On this PCB they do use adhesive for securing the large electrolytics.

[Psi]

If it's on the edge of the PCB and you're making this PCB yourself, then you can add a hole to thread the wire through first. Or a fancy routed slot system to hook/hold the wire

[AndyBeez]

Hot melt glue, a.k.a. 'liquid snot' is perfectly okay for providing mechanical support in electronics where the part temperature does not go too far above ambient. So okay for wire joint support, but not suitable for heatsinks! In your photo, the glupe is sitting on the solder mask, so corrosion is not an issue. Hot melt glue comes in a rainbow of colours, but avoid the crafter's decoupage glues with 'sparkles', as the could be very conductive.

[wraper]

Hot melt glue, a.k.a. 'liquid snot' is perfectly okay for providing mechanical support in electronics where the part temperature does not go too far above ambient. So okay for wire joint support, but not suitable for heatsinks! In your photo, the glupe is sitting on the solder mask, so corrosion is not an issue. Hot melt glue comes in a rainbow of colours, but avoid the crafter's decoupage glues with 'sparkles', as the could be very conductive.

Hot melt is "OK" is you don't expect it to hold more than a hear in vibration free environment. I've rarely seen hot melt glue still adhering to PCB in equipment I've seen it in.

[eugene]

I have routinely used UV cure adhesives when working in a lab that has the material and a UV 'pen' available. This is only on prototypes and such; I'm not sure of the long term suitability. UV pens made for the purpose can be expensive, but UV LED's bright enough for the job can be purchased for under $10. I'll likely end up building something to post cure SLA prints, so I might buy a syringe of UV adhesive for use at home.

[AndyBeez]

Agreed, hot melt can detatch if it gets too cold.

Google for T7000 or T8000 adhesives. These are super strong glues used primarily for mobile phone and circuit repairs. Overkill for harnessing, but we have no idea how many newtons of force your solder joints have to endure? I've a tube of T8000 that's been a 'life saver' many times.

[Zero999]

https://www.myconsumables.com/product/wp100-lmn-high-grade-neutral-cure-silicone-sealant/?attribute_silicone-colour=White&utm_source=Google%20Shopping&utm_campaign=MYconsumables%20product%20feed&utm_medium=cpc&utm_term=22273&gclid=CjwKCAjwkMeUBhBuEiwA4hpqECKu73HK4EYWgQU6yEotFLnlcu3Nl5Hw7lkk5Iky_hQrOg5A4LFInhoCX6kQAvD_BwE

[xavier60]

I use this, https://threebond-europe.com/products/tb1530c/
Not locally available in some countries. 

[3roomlab]

there is this method used by some

[Psi]

Here is some PCB safe silicone that is reasonably priced and not a HUGE amount that you will never use before it expires.

https://www.digikey.co.nz/en/products/detail/chip-quik-inc/EGS10B-20G/10059588