Staking and potting are not often used in the hobby electronics world, not really entering to the common vernacular. However, everyone who’s ever busted out a glue-gun to convince that dang wire that keeps coming loose to stay has done it.
However, as [Sean Thomas] touches on, staking is not necessarily as easy as a dob of hot glue. There is a method to the madness. [Sean] gives some examples in pictures, but also directs people to the excellent NASA standard methods for staking. It’s surprising how many unintuitive caveats there are to the proper technique.
Potting, or covering everything in epoxy forever, is a great way to get a waterproof, unserviceable, and practically mechanically invincible circuit. The big challenge in potting is picking the right material. A soft silicone, for example, might transfer an unexpected force to an unexpected section of the circuit and cause a mechanical failure. A nice hard epoxy may be too insulating and cause a thermal failure. The standard RTV from the big box store has acetic acid that will eat your components.
These two techniques that come in handy when you need them and worth the bit of reading it takes to get familiar. Have you used either in your own workshop? Let us know the application and the material/techniques you have tried in the comments below.
Epoxy resin is useful stuff. Whether for gluing stuff together or potting components, epoxy is a cheap and versatile polymer that finds its way into many hackish projects. But let’s face it – the stock color of most commercially available epoxies lacks a certain pizzazz. Luckily, [Rupert Hirst] at Tallman Labs shows us that epoxy is easily tinted with toner powder from a laser printer or copier.
Looking for a way to make his epoxy blend into a glue-up, [Rupert] also demonstrates that colored epoxy makes a professional looking potting compound. There’s just something about the silky, liquid look of a blob of cured black epoxy. [Rupert] harvested his toner powder from a depleted printer cartridge; only a smidgen is needed, so you should be able to recover plenty before recycling the cartridge. We’ve got to admit that seeing toner handled without gloves gives us the willies, though. And don’t forget that you can find cyan, magenta and yellow cartridges too if basic black isn’t your thing.
Sometimes it’s better to leave your epoxy somewhat clear, like when you’re potting an LED matrix for a pendant. But this neat trick might just spiff up your next project a bit.
If you want to improve the reliability of your electronics, just cover them in silicone or epoxy. Potting, as this technique is called, protects your project from impact and loose wires, but most of the time ends up as a gloppy mess. [Charles] figured out an awesome way to make pro-looking potted electronics using silicone and a few supplies from the emergency room.
On one of [Charles]’s trips to the ER, a nurse put Tegaderm on a wound and he noticed his skin could breathe. Figuring Tegaderm would also allow silicone to breathe, he asked for a sample and went back to the lab. After putting a few globs of silicone on a PCB, [Charles] wrapped the whole thing in Tegaderm. Much to his surprise, the silicone cured and made a smooth, glossy protective covering on his board.
[Charles] put up a Picassa album of his Tegaderm/silicone potted electronics, and we’ve got to say they’re looking very professional. This technique could also be applied to [Charles]’ glass PCB touch sensor, allowing for the creation of clear (or at least tranlucent) PCBs.
After the break, you can check out [Charles] potting his ATtinyISP board in silicone with Tegaderm. One word of warning, though: don’t use a silicone that uses acetic acid to cure – that’s a death sentence to electronics. Luckily, there’s an easy test to see if your particular brand of silicone produces acetic acid while curing. Just squeeze a bit of silicone on a piece of scrap, and if it smells like vinegar after a while, don’t use it.
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