I have a piece of test equipment that needs to stay underwater for days. Normally I would use or make a waterproof case with a lid and a gasket.
Instead, I’m wondering if I could print a box, pause the print just before the top face, put the device inside and then print the top face over it. No openings, no nothing, and the device works by induction so it doesn’t need to physically connect to anything.
But this would only work if 3D-printed PLA walls are really waterproof. After all, 3D-printed features are kind of a bunch of wires more or less loosely attached to each other, so I wouldn’t be surprised if water could leak through under pressure.
Before I spend any time assessing this myself, has anybody tried printing waterproof enclosures?
I’ve played around with using PLA to make plant pots on an old Ender 3. It wasn’t quite waterproof, but pretty close. If you wanted a perfect seal for underwater shenanigans, I’d probably experiment with different wall thickness settings, and maybe temperatures/fan cooling settings. You want to try and minimise the tiny air pockets between layer and filament drawing lines. (Resin 3D printers are probably better at this tbh.)
I had reasonable success using a hot air gun to melt the outer layer of PLA to make it perfectly smooth, but this can deform your object if it heats up too much, so I’m guessing very hot temperatures and less contact time would be the ideal setting.
You could also try smearing Vaseline or resin coating the outside of the object.