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Will 3D Printing Resin or Filament Dissolve in Water?

3D Printing resin and filament are actually two different materials. Filament is a thermoplastic strand used to create objects, while resin is a liquid photopolymer that's hardened during the process.

Written by:
Ben
Last updated:
11/16/2023

3D Printing resin and filament are actually two different materials. Filament is a thermoplastic strand used to create objects, while resin is a liquid photopolymer that’s hardened during the process. Due to its nature, you may wonder how it interacts with water and whether it will dissolve in it. 

Your resin and filament won’t necessarily dissolve in water. However, both materials are sensitive to water and may be damaged by it over time. Some kinds of resin are water-soluble, some types can be merely damaged by water, and some are water-resistant. 

In this article, I’ll give you some basic information on how resin works in 3D printing, how it reacts in contact with water, and what you can do to prevent damage.

3D Printing With Filament vs. Resin: Reactions to Water

3D printing comes in two different varieties, based on the two primary materials: filament or resin. Of course, both materials come in many different variations, but these are the two general categories. 

  • Filament. Simply speaking, it’s a thin thread of thermoplastic, which gets heated up until it’s soft enough to mold, and then fed through an extruder in order to create a 3D object. This melted material is then placed layer by layer until your desired object is done. It’s sometimes referred to as FDM, which stands for Fused Deposition Modeling. 
  • Resin. Resin printing works fundamentally differently, and I’d even say, in a more complex way. It’s other and more technical name is stereolithography. It relies on a process called photopolymerization, which means that it relies on a liquid that changes its characteristics when exposed to light, in this case, UV light. 

These liquids are referred to as photopolymers or light-activated resins. However, in the 3D printing community, they’re referred to as simply resins. 

The process boils down to a UV light drawing the pattern of a single layer in the resin, which hardens afterward. This is repeated layer by layer until you’re left with a finished product. However, after this process, you will need to add some finishing touches. 

How Filament and Resin React to Water

Both materials tend not to be waterproof and can be damaged by exposure to water. However, they can be treated for that and thus be made more durable and water-resistant. 

For example, filament can be treated by increasing the height and thickness of the walls, which will make it more water-resistant. Another simple way is to apply some epoxy resin to the finished product. 

Alternatively, you can opt for a filament that resists water well, even though this might make it more expensive. 

Things can get slightly more complicated when it comes to resin, as it tends not to get on well with water. 

There are different kinds of resins when it comes to water solubility. Some types are deliberately made to be water-soluble, some aren’t soluble but can be damaged by water (standard resin), and some are made to be water-resistant, that is, water-washable.

Therefore, you can choose water-washable resin if you really need to treat it with water. In general, however, it’s best to avoid unnecessary contact between your resin-printed objects and water.

Determining Which Technology Is Better for You

While both options have pros and cons, the one that’s better for you may change based on your needs. Filament printers may be better in terms of cost-effectiveness, but resin printers may produce better products. 

Filament printers tend to be more cost-effective, as you can get them for as little as $200. It doesn’t produce such great results in terms of smoothness and details as SLA, but it’ll give you tons of practice and great results for non-commercial use. It’s also an excellent option for novices and hobbyists. 

On the other hand, resin printers will set you back significantly more in terms of money. However, you get a decent bang for your buck, as resin allows you to better detail your products and create outstanding pieces. If you want to focus on aesthetics and the price isn’t crucial, this may be the better option for you.

Furthermore, FDM tends to create more durable products, while SLA prints can be damaged by exposure to sunlight. Also, SLA requires more post-printing work to finish the job. This includes removing the supports, washing the print, and applying finishing touches to make it smoother.

3D Printing With Water-Washable Resin

The water-washable resin may be the right choice for you. It allows you to clean your finished products without using any additional chemicals, like alcohol, which makes the process much easier, and the water won’t damage your resin.

Also, this kind of resin is easier to clean if there are any spills, and it generally emits fewer fumes and thus has a weaker smell. This can make it easier to work with if you’re particularly sensitive to such things. 

However, it has some drawbacks, as it tends to be costly and brittle after being treated with water. Furthermore, if there’s some leftover water in the details, it can cause overcuring. This may create a product that is of lesser quality. 

Leftover water may cause cracks and layer splitting, as well, and you need to really pay attention to how and where you store the prints. 

  • If you’re going for simplicity and easier work, go for water-washable resin.
  • You can also choose it if making water-resistant products is essential to you for some other reason.
  • Choose standard resin if you’re aiming for greater details, more durability, and more elasticity.

Conclusion

As we have seen, both types of materials can be damaged by water. You can mitigate this by making the right choices and assessing your priorities. 

When it comes to resin, you have the option of getting some water-washable resin. However, you should keep in mind that this has drawbacks regarding the quality of the final product. 

When it comes to filament, you have the option of buying a water-resistant kind or making the prints thicker. 

Based on everything mentioned above, I’d recommend adjusting your printing techniques to avoid contact with water whatsoever.

Written by:
Ben
Last updated:
11/16/2023

About Ben

I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.