The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Day: November 26, 2012

  • Waterproof RGB LED Strip

    Another package from halfway around the planet brought 5 meters of waterproof RGB LED strip, which may be useful for projects like longboard lighting. Not having worked with a waterproof strip before, I snipped off a segment:

    Waterproof RGB LED Strip - one segment
    Waterproof RGB LED Strip – one segment

    The waterproof coating seems to be a soft silicone or acrylic pour with roughly the consistency of Gummy Bear tummy, so cutting it off requires a delicate touch to avoid slicing the flex circuit board:

    Waterproof RGB LED Strip - peeled top
    Waterproof RGB LED Strip – peeled top

    It doesn’t actually bond to the circuit board, though, and if you get a sharp blade underneath, can be peeled away. I suspect this means water will eventually make its way into the circuitry and you shouldn’t expect to submerge the strip in a fish tank. I scraped the contacts clean, which probably isn’t the right way to do it:

    Waterproof RGB LED Strip - end view
    Waterproof RGB LED Strip – end view

    The underside makes no pretension of being waterproof and you can peel / roll / rub the adhesive off the contacts:

    Waterproof RGB LED Strip - peeled bottom
    Waterproof RGB LED Strip – peeled bottom

    Does anyone else doubt the authenticity of that 3M logo? The production values look rather low, but maybe it’s just me.

    The trouble with soldering contacts to the bottom is the ensuing lump that prevents good adhesive bonding. The trouble with soldering contacts on the top is the surgery required to remove the coating. You can get punch-through contacts with snake-bite fangs, but even the vendors admit to about a 20% failure rate, which implies it’s pretty much a crapshoot.