Are PLA & ABS Filaments Waterproof ?! What Are Your Options!


ABS is used to make some of the household goods consumers use everyday. Flexible and durable, ABS  is used to make everything from wall sockets to Lego blocks.

Although it plays second best to PLA, ABS has several characteristics that make it a better material to print with. While they can be used interchangeably ABS offers better mechanical strength, heat and water resistance compared to PLA. 

Perhaps the only downsides to ABS in comparison to PLA are that it is more difficult to print with, emits more toxic fumes and produces a strong odor. But how does ABS really perform when exposed to heat or water? 

We also highly recommend that you check out our post “How Do I Choose The Right Filament? (Beginner Guide)

What 3D Filaments Are Waterproof?

3D filaments absorb moisture when not properly stored. Wet filament will produce prints that are materially weak and have surface defects like holes or gaps. Most filaments including ABS, nylon and PLA are waterproof. 

Water absorption reduces the mechanical strength of the filament. Certain filaments like nylon absorb water more readily than others. Generally,

PLA and ABS filaments are less water absorbent. Proper storage prevents moisture absorption which in turn produces better prints.

We highly recommend that you check out our post “Does PLA Have A Shelf Life? How long & How To Store It for A longer Shelf Life!

But what about a 3D print made from a particular filament? For example, if you plan on printing something like a plug or stopper out of PLA, what will happen when it is exposed to water?

How Water Affects 3D Prints?

First off it is important to get a clear definition of what waterproof means in relation to 3D printing. There are two facets to consider, namely watertight and waterproof

  • Watertight means the printed item is impermeable or non-porous. Water or any other liquid cannot go in or out of it. If you wanted to print a water bottle then you would have to make it watertight. The same would apply for a stopper.
  • Waterproof simply means the printed item is not affected by water. It will not dissolve or start to break down soon as it comes into contact with water. If you wanted to print a shower head you would need to make it waterproof but not necessarily watertight. The same would apply for outdoor items that might be exposed to rain.

An item can be waterproof but not watertight. When printing items that will come into contact with water, you want to consider how the material you are printing reacts to water.

What would you print with if you wanted something that could stand up well to water?

  • PLA could be your first choice. It is easy to print with and can be used for any wet environment. It is important to point out that PLA has better resistance to cold than hot water.
  • ABS would be the second choice. While not as easy to print, it is more durable than PLA. ABS printed parts can hold up to moisture exposure for years without any deterioration. 
  • Most food containers like disposable soda and water bottles are made from PET. PETG is a derivative of PET so can be used to make watertight items. 

It’s important to stress that anything that will come into contact with food should be printed using food safe filament only. This rules out ABS, as it is too toxic. PLA and PETG are considered food safe.

How To Make 3D Prints Waterproof ?

You can make a 3D print more waterproof by following a few steps.

  1. Use more outer shells on your print.
  2. Fill in gaps and holes through smoothing. Acetone, epoxy and wax are the most commonly used solvents for layer smoothing. 

sherifjallad

I am a very well experienced techie civil engineer who's extensively interested in 3D printing technology and even more captivated by the potential of 3D printing livable structures

Recent Posts