SLS Nylon and waterproof-ness

[bear30]

Hi Everyone

Just a quick question really. If I print a part using SLS Nylon PA12 like you use in a Sinterit Lisa or Sintratec type machine. I just want to know if the parts are technically waterpoof. I’m not making a cup or container, just something that will be outside, in weather for a few years.

I read that Nylon is porous and you need to finish it properly, but can;t find anything that is definitive on the subject.

Any help appreciated.

[TypeR]

I don’t do SLS printing, but from what I know, SLS is inherently NOT waterproof at all.
Nylon in itself is of course not porous, but as all the parts are sintered together there are small opening in between them.
Think of SLS as making a pile of ping-pong balls and then pour glue over them.
The balls will be glued together, but if the glue has not filled all the voids in between the balls, the resulting object is not watertight.

[bear30]

So parts I make are not designed to be watertight, I just use them in “rugged” conditions. So, a good example would be a belt clip that I print in SLS printed Nylon that I then stick to a device. Or a gopro clip that would be used on a boat or surfboard.

So the design would not need to be “waterproof/watertight”, I just need the material to be water proof in terms of not affecting or degrading the nylon part over time.

Is nylon OK for this or would a part over time let the water damage/degrade/warpe etc the part over time?

[3D_Printing_Chi]

So nylon won’t hold water, it is kind of like a sieve. But if all you’re looking for is for it to be weatherproof, it should last for some time in the elements. All plastics will degrade to some extent when exposed to the elements, with cycles of sun/heat/rain/ freezing/ice, and so on. Nylon is probably better than some other plastics in this regard. The nice thing about 3D printing is that once you have the design once one wears out you can always just print another one.