splash proofing a tPLA model

[aag 6]

Is it possible to achieve IP64 or IP65 splash-proofing of a Tough-PLA print? I must design an outdoor case for low-voltage (5-12V) electronics equipment. If I print with 100% infill, what is the minimal wall thickness that would afford protection from rain/snow/moisture?

[Smithy 1,144]

I think the biggest problem is moisture and I don't think you will get it really airtight. Rain and snow should be no problem, but I had this year the case that the electronics from my pool pump was not working anymore because of corrosion inside due to moisture from the air. It was sealed and anything, but a very small crack was enough to destroy the board inside.

 

I am not sure, but I found some days ago a material in a shop where I think it was watertight, I think it was something from FormFutura but not sure. I think the filament needs to expand a little bit to get it really tight.

 

But in any case, when you print the case, put it for 2-3 days in water completely and check if it is still dry afterwards. When it is outside all the time, I think this is really important.

 

Regarding the wall thickness, I would use as much walls as possible (>4 or5) and use bigger layer heights. Also print hotter to get a really good layer adhesion and bonding.

 

And if possible use some primer spray in post processing to be on the safe side, but that's often not an option but I wanted to mention it.

[ahoeben 1,965]

If you are worried about water getting in through the layers, you can also apply a coating to the print.

[geert_2 558]

When printing a filter in PLA, I used only one wall of 0.5mm, and very thin layers and slow speed, to get it water-tight. It is mostly the thin layers (0.06mm) and slow speed that does it. When printing at 0.3mm layer-heigth, I got lots of tiny waterjets squirting out, like from a very thin injection needle. But I would recommend multiple nozzle-diameter lines, at least two.

 

But the parts are very likely to warp in the sun, if outdoors. And the material might gradually degrade due to moisture and UV-light, like most plastics.

 

So I would also encapsulate the electronics in silicone (if it doesn't require regular recalibration or maintenance). You see this also on encapsulated transformers, or on the bottom of tooth brushes (the charger). Companies like RS-components and Farnell do sell silicones for potting electronics.

 

These pictures show the concept. The bottom was printed with 70% infill or so, to make it porous and act like a filter, to prevent ingestion of parts into a vacuum pump. Yes, I could have bought a filter, but I wanted to try printing one...

 

Edited October 28, 2020 by geert_2