Soldering in high-humidity (80% RH) environments?

[victorhooi]

I'm doing an LED strip install in a very cold and humid environment.

I was told by the customers that the strips wouldn't get wet, and they didn't need IP-rated strips...but let's just say that's not entirely true.

Anyway, in terms of soldering wires to the end - I'm also having issues soldering on 16 AWG wires to the copper contacts on the strips.

The RH (relative humidity is around 80%), and there's also lots of water condensation on the surfaces:





I do seem to be having a lot of trouble getting a good solid solder joint - and even then, it's not a nice shiny silver colour.

Has anybody soldered much in high-humidity environments, and do you have any advice?

Also - what exactly is happening here, from a physical/chemical POV?

Finally - from what I've read, the flux is somewhat hygroscopic, so it's causing to cause issues with the ambient humidity. Does anybody know more about how flux reacts in high-humidity (>= 80% RH) as well?

[Jeroen3]

When stuff is stored moist or wet, copper or component platings will oxidate and you will never be able to solder to them correctly.
The parts need to be scrapped.

Maybe, you could do something if you add extra paste flux, but it needs to be dry first.
So, either dry this, with hot air? Or solder before mounting in the wet space.

But if it condeses this wet, it will not have a long life...

[moffy]

With that level of condensation/moisture the LED strips are not going to survive very long.

[MathWizard]

Cleaning the surfaces with a bit of sandpaper can really help too, before using flux as well.

I know some wire types, can be horrible to solder to. Like I have some cheap, male barrel jacks, like for 12V, and it has what looks like tinned silvery stranded wire. And even with good flux that works on everything, this stuff will barely take solder.

[Zipdox]

This is a perfect task for a fiberglass pen. They are made for cleaning contacts. That being said, in the pictures it looks like the strips are stuck to aluminum. That's gonna suck away a lot of heat, especially if wet. You could preheat the area with a hot air gun or hairdryer.