Water-Washable Resin: Advantages and How to Use It for Printing without Alcohol

Water-washable resin is a type of photopolymer that cleans up with running water instead of chemical solvents, greatly simplifying the post-processing of 3D printing. In my experience, this resin has been a game-changer for my projects, allowing me to work more safely, cleanly, and economically.

If you're thinking about making the jump to resin printing, I can assure you that water-washable resins are the easiest way to get started. Say goodbye to the strong smells of isopropyl alcohol and all the hassle. Pure convenience! 🤙

What is water-washable resin and how does it work?

Water-washable resin is a photopolymer designed so that the parts not solidified by UV light dissolve in water, eliminating the need to use isopropyl alcohol for washing. This makes the process safer, more economical, and accessible to all makers.

Unlike standard resins, which require you to use chemicals to remove excess sticky material, this alternative simplifies post-processing in an incredible way. It's like cleaning a mud stain instead of an oil one.

The trick lies in its formulation. Manufacturers incorporate "hydrophilic" components into the mix, which are basically water-friendly. When the UV light from your printer solidifies the part, these components become fixed in the structure. However, all the liquid resin that hasn't been exposed to light remains water-soluble. That's why, when you place the part in a container with water, the excess dissolves and washes away.

In my workshop, the change was radical. Going from handling bottles of IPA with gloves and a mask to simply using a container with tap water has saved me time, money, and more than a few headaches from the fumes. It's a cleaner, safer process and, above all, infinitely more convenient.

And it's not a passing trend. I've seen that water-washable resins already account for nearly 25% of the market in Spain and can cut your expenses by up to 40%. For someone who prints as frequently as I do, this can mean savings of more than 50 euros a month on alcohol alone.

What are the advantages of using water-washable resin?

The main advantage of using water-washable resin is that it eliminates the need for isopropyl alcohol, which translates into direct cost savings, a safer working environment with fewer fumes, and a much faster and simpler washing process.

For me, these are no minor advantages — they completely transform the printing experience! I've tested many brands and I can assure you that once you switch to water, it's hard to go back. Here I break down the benefits I've noticed in my day-to-day use.

1. No alcohol: direct savings in your pocket

This is the easiest advantage to calculate. A good-quality bottle of isopropyl alcohol can cost you between 5 and 10 euros per litre. Even if you reuse it, it gradually becomes saturated with resin and loses effectiveness, forcing you to buy more again and again.

With water-washable resin, this cost disappears. Tap water is practically free. That saving, which may seem like a small thing at first, adds up to hundreds of euros a year that you can reinvest in more resin, a better 3D printer, or some quality paints to bring your pieces to life.

2. Less smell: a safer and more pleasant workshop

Isopropyl alcohol is flammable and its vapors, aside from having a smell that knocks you flat, can be irritating. Working with it forces you to have excellent ventilation and take extra precautions to avoid any nasty surprises.

Water-washable resins smell much less. Keep in mind, no resin is completely odorless (and I always recommend wearing a mask), but the difference is enormous. This is key if your workshop is in a room at home, in a small apartment, or if there are children or pets wandering around.

In my experience, the change is like night and day. You go from having a "chemistry lab" to a much more pleasant creative corner. Being able to clean a piece without the whole house smelling like solvent is a luxury you truly appreciate.

The impact on safety and the environment is so significant that these resins are expected to capture a 35% market share by 2035. Users themselves report 50% fewer skin irritation incidents compared to IPA. If you want to dive deeper into the topic, you can discover more data about the resin market and its evolution at Research Nester{: rel="nofollow noopener noreferrer" target="_blank"}.

3. Faster and simpler post-processing

Time is money, right? Well, washing with water is not only safer, but also much faster. Instead of dealing with two containers (one for the initial "dirty" wash and another for the final rinse), you can do it all in a single container with water and a soft brush.

• Fewer supplies needed: Forget about expensive washing stations if you don't want them. A simple plastic container and a UV lamp work perfectly.
• More efficient cleaning: With a resin like the Elegoo Water Washable V2.0, a couple of minutes of gentle swirling in warm water is all it takes.
• Effortless waste management: Although contaminated water should not go down the drain, treating it is much easier, as I will explain later.

How do you use water-washable resin? My step-by-step guide

Using water-washable resin is very straightforward, but to get the best results, follow this process: prepare the resin by shaking it, use the correct settings in your slicer, wash the piece in water, dry it completely, and cure it with UV light, without forgetting to treat the waste water.

Over the years, I have refined a method that works wonderfully for achieving clean, detailed, and durable pieces. Here I share it all with you, friend to friend.

1. Preparing and configuring the 3D printer

Everything starts long before you hit the print button. The first thing, and this is sacred: shake the resin bottle well. Trust me, this step is crucial. A good shake of around 30-60 seconds ensures a homogeneous mix.

Now, the settings in your slicer. Water-washable resins often require exposure times slightly longer than standard resin. As a starting point, I recommend the following:

• Layer height: 0.05 mm is a standard that gives a great balance.
• Exposure time per layer: Stay between 2.5 and 4 seconds. Start with 3 seconds and run calibration tests.
• First layers exposure: Give them plenty, between 25 and 40 seconds, to ensure a good grip.

For example, with the Anycubic Water Wash Resin 2.0, I've achieved spectacular results with just 2.8 seconds per layer.

2. Step-by-step washing process

Once the 3D printer has finished, carefully remove the platform and let the excess resin drip back into the tank. To clean the piece, you only need:

1. A plastic container with enough space to submerge the piece.
2. Tap water, at room temperature or slightly warm.
3. An old toothbrush or a soft-bristle brush.

Submerge the figure in the water and move it gently. Use the brush to carefully clean the details. This process shouldn't take you more than 2 or 3 minutes.

My pro tip: Prepare two containers. The first for a quick "pre-wash" where you'll remove 90% of the resin. The second, with clean water, for a final rinse that will leave the piece spotless.

3. Drying: the key to avoiding cracks

Hold on! Don't rush to cure the piece. If you cure a piece that still has water on it, you're almost guaranteed to end up with cracks.

After washing it, use compressed air or a hair dryer on cool mode to remove any visible water. Then, leave it in a dry, well-ventilated spot for at least one to two hours before curing it.

4. Wastewater treatment (important!)

I'm going to be serious here. NEVER, I repeat, NEVER pour the dirty water down the drain. It contains resin particles that are toxic to the environment.

Managing this waste is very easy:

1. Pour the contaminated water into a transparent container that you can seal.
2. Leave it in the sun for 2 or 3 days. The sun's UV light will solidify the dissolved resin.
3. When you see a solid sediment, filter the water using a coffee filter.
4. The filtered water is now safe to pour down the drain, and the solid residue goes in the regular trash.

5. UV curing: the finishing touch

We've reached the final step: UV curing, which hardens the piece. You can use a curing station or a UV lamp. For a 28-32 mm miniature, between 2 and 5 minutes is usually enough. Watch out for over-curing!

What are the limitations of water-washable resin?

The main limitation of water-washable resin is its lower mechanical resistance and greater brittleness compared to standard resin or ABS-Like resins. It is also more sensitive to moisture during washing, which can cause cracks if not dried properly.

Although I'm an unconditional fan, it's time to be honest so you know what you're getting into. Its main Achilles' heel is that pieces tend to be more brittle.

The Shore D hardness of a standard water-washable resin sits around 80-84D, while an ABS-Like resin falls in the 88-92D range. What does this mean? That they're more prone to breaking if dropped. They're great for display miniatures, but if you're planning to print mechanical parts, my advice is to look for other options.

To avoid the problem of moisture cracks, drying is sacred. You need to make sure the piece is 100% dry before putting it under the UV lamp. A great trick is to use compressed air and then let it rest for 1-2 hours. For extra strength, you can apply a coat of varnish or use a hybrid resin like the ABS-Like V2 water-washable resin, which combines water washing with greater hardness.

Comparison: Water Washable vs Standard vs ABS-Like

So you can see everything at a glance, I've put together this comparison table. It will help you choose the right resin for each job, analysing washing, strength and what each one is ideal for. It's my ultimate cheat sheet!

At the end of the day, there is no "best" resin, only the "right" resin. If your priority is convenience and safety, water-washable resin is your best friend. If you're looking for maximum durability, ABS-Like is the answer. And if you want a reliable balance, standard resin never lets you down. If you want to dive deeper into this topic, I suggest taking a look at my guide on the different types of resins for 3D printers.

Who is water-washable resin ideal for?

Water-washable resin is ideal for beginners in 3D printing, users with enclosed or small workspaces, and anyone who wants a simpler, safer and more affordable post-processing process without the need to handle flammable alcohols.

In my opinion, if you identify with any of these profiles, this resin is for you!

• Beginners: It removes the entry barrier of handling chemical products.
• Makers in flats or small spaces: It drastically reduces odours and the risks associated with alcohol.
• Miniature and figure enthusiasts: It offers spectacular detail and is perfect for display pieces.

Frequently Asked Questions (FAQ)

Whenever I talk about water-washable resin, I always get the same questions. So I've decided to gather them all here so you have them handy and can resolve them once and for all. Let's get into it!

Can you use tap water to clean the parts?

Absolutely! That's precisely its biggest advantage. You can use plain running water without any issues, and if it's slightly warm, it works even better for dissolving uncured resin residue in just 2-3 minutes.

Does water-washable resin smell less than standard resin?

Yes, the difference is like night and day. Although no resin is 100% odorless, the smell of water-washable resin is much milder and you avoid the intense fumes of isopropyl alcohol.

What do I do with the dirty water after washing?

Never pour it down the drain. Pour it into a transparent container, leave it in the sun for a couple of days so the resin solidifies, then filter the clean water and throw the solid residue in the trash.

Are the final parts just as resistant as with standard resin?

Generally no, they are a bit more brittle, making them ideal for display figures. For functional parts that need more durability, I recommend a resin with better mechanical properties, such as the ABS-Like V2 water-washable resin.

Conclusion

And with that, you now have the complete picture to decide whether water-washable resin is your next great ally. If you're looking to simplify your life, save a few euros, and work in a cleaner space with fewer odors, the answer is a resounding yes. Trust me, it's a total game-changer in terms of convenience.

It's true that they aren't as robust as other resins, but for the vast majority of miniatures, busts, or display figures, they are more than sufficient and the level of detail is incredible. My straightforward advice, from one enthusiast to another, is simple: try it. Grab a bottle, run your first print, and experience firsthand just how easy it is. You're going to be amazed!