Can 3-D Printed Parts be Waterproof?

A common question in the 3-D printing world is, can 3-D printed parts be waterproof? Let's discuss it.  
 
The common wisdom is that since 3d printing is built up in layers. It can't be made waterproof because those layers allow water to pass through, therefore 3d printed parts are porous. This is incorrect, it's a misconception, that is easy to get a hold of but really isn't true, in the context of how 3d printing works because it's kind of a remnant of old FDM 3d printing that wasn't very reliable or very consistent which could potentially leak. Anymore it's really not an issue but there are some caveats to that.  

 Number one can you make a floating part? Absolutely! 

All of these are perfectly waterproof products that were made with FDM 3d printing. It's really not that odd that 3d printing can be waterproof. If you put down a layer of plastic and then you put down another consistent layer of plastic on it and then a layer on top of that and then they sandwich together, it’s very similar to using glue in a gasket or any sort of gasket lube that can be used to seal up a machined part. In both cases, you're just putting down a layer of plastic and then compressing it. A 3d printer is able to put down a hot layer and if it is consistent, it merges consistently with the layer below it. There are a few other tricks that you can do in order to get a good seal. You can also as you're going along not just do a single layer that has to seal itself but do multiple layers so that you get thickness on the part. This allows more redundancy should one of those individual beads be compromised in some kind of way. 

We've worked really hard on waterproof 3d printing up in high-pressure applications that we continue to work on it right now and push the technology further. For high pressure, it is very difficult, but it is not impossible. The reason it's difficult is that the larger the part becomes the more opportunity there is for a defect in the part that could cause a leak. If you're doing waterproof or high-pressure applications generally you want to keep it down to no larger than fist size. If you go larger than that it's exceptionally hard because you have tens, of thousands, if not millions of tool moves. If a few of them go wrong in just the right way you can have a leak. Very often the leak is exceptionally small and cannot be seen until it reaches very high pressure.  

To summarize, lower pressure applications are very easy. Floating objects are very easy so yes 3d printed parts can absolutely be waterproof. It just helps if you know what you are doing. There's no reason that they physically can't be able to be waterproof.   

So yes, you can make waterproof 3d printed parts!

​Happy Printing!