How To Clean Up Your 3D Printed Miniatures (DIY Guide)

3D printing offers an excellent way to build your miniature collection. However, 3D printed objects aren’t perfect right off the print bed and usually come along with supports, brims, rafts, and stringing. As such, you need to remove these extra artifacts before settling the miniature on your table or mantel. 

Here’s how to clean up your 3D printed miniatures: 

1. Wash the miniatures. 
2. Remove the rafts and supports. 
3. Clip, cut, and tweeze the strings and unwanted protrusions. 
4. Sand out the remaining irregularities. 
5. Smoothen the miniature using post-processing techniques. 

In this article, I’ll go over each of these steps in detail. This should help you follow along and get your 3D printed miniatures cleaned up and looking store-bought. I’ve also made sure to add specific tutorials depending on the type of printing method you used – FDM or resin, as well as the printing material – PLA, ABS, resin, etc. 

1. Wash the Miniatures 

If you’re dealing with resin prints, you likely already know the importance of washing and curing prints before working with them. Overall, it’s good practice to wash 3D prints before proceeding with the clean-up process.

However, if this is your first time dealing with SLA printers, you can check out this excellent 12-min YouTube video on the basics of SLA printers, a.k.a resin printers: 

That said, washing is also beneficial for FDM prints. It’s a good way to remove any loose materials attached to the print, like strings or blobs. 

To wash the miniatures (mini) from FDM printers, I recommend using an isopropyl alcohol bath. Soapy water can just as effectively clean your prints, but it’s important to ensure isopropyl alcohol doesn’t get trapped inside the mini, as this can lead to mold formation. As such, if you don’t have an air-tight print, it’s best to go with isopropyl or acetone baths. 

Simply submerge the mini into the bath and gently scrub it using either a toothbrush or a sponge. Once you feel like you can’t remove any more debris, take the mini out of the bath, and dry it using a paper towel or let air dry. 

2. Remove the Rafts and Supports

Once miniatures are washed (and cured for SLA prints), it’s time to start the heavy-duty clean-up process: removing the rafts and supports. 

I recommend removing the raft first. 

To do this, try to gently bend or pry off the raft from the mini. However, don’t apply all your force from one location because it can lead to breaks or cracks. Instead, work yourself around the mini applying mild pressure as the raft slowly becomes loose and eventually comes off. 

The best thing about removing the raft first is that it almost always takes some of the support structures with it. 

Once the raft comes off, it’s time to deal with the supports. Start with the bigger, empty structures that aren’t hiding or shielding any crucial parts of the mini:

1. Use a needle-nose plier to grab the support and apply some pressure to break them. 
2. Start twisting and tugging the parts to loosen them from your mini. 
3. Once you feel it’s loose enough, gently yank them out. 

Repeat this process until you remove all the big support pieces to reveal the smaller ones. 

You can use the same technique to remove these, but you’ll need something smaller than pliers. I recommend using needle-nose tweezers or even eyebrow pluckers. 

If there are support structures inside small holes or crevices in your mini, tweezers most likely won’t reach them. In that case, use a toothpick to push and break the support piece, so it comes out. You can now use your tweezers to twist, tug, and yank out the piece. 

3. Clip, Cut, & Tweeze the Strings and Unwanted Protrusions

After removing the supports and rafts, it’s time to deal with any strings as well as protrusions that remained after removing the support structures. 

To deal with the leftover support marks, you have a few options: 

Use an Exacto Knife

Exacto knives are an easy go-to for slicing off protrusions. Be careful with this method, as it’s a bit difficult to get the knife under the material to get a clean cut. Plus, one wrong move can cut the miniature or even your finger. 

Use a Nail Filer 

A nail filer can be used to scrub and eventually erase most of the support marks and protrusions. However, this technique only works with harder models since you’ll need to apply pressure when filing, which can break delicate areas in your build. 

Use a Hot Knife 

This is my favorite method because the heat makes cutting much easier. I recommend something like the WINONS Hot Knife (available on Amazon) because it reaches 212°F (100°C), which is hot enough to smoothly cut through the 3D prints without burning or discoloring the material. 

Use a Heat Gun

A popular way to deal with surface-level irregularities is by using a heat gun like the Genesis GHG1500A Heat Gun Kit (also available on Amazon). In fact, it’s one of the best ways to deal with stringing since heating the strings causes them to retract back into the structure. 

However, you need to be careful about which parts you use the heat gun on and for how long. 

For example, heat guns are great at removing stringing or small protrusions on larger, more solid blocks of your mini. However, if you use it near smaller, thinner areas of your miniature, it can melt that structure. 

That said, even larger portions of your prints can start to melt if you use the heat gun long enough. 

As such, my recommendation is to apply the heat gun for a few seconds just to soften up the strings and protrusions. Then cut them off using horizontal cutters or an Exacto knife. 

4. Sand Out the Remaining Irregularities

With all the supports, strings, and protrusions cleared up, your miniature is starting to look good. Now, all it needs is proper sanding to take care of the remaining irregularities. 

Most beginners make the mistake of buying sanding twigs for this. However, you can save money and make the process more convenient with a little DIY hack. 

Simply wrap a piece of sandpaper around the tip of a skewer and secure with super glue. You now have a homemade sanding twig that’s small and narrow enough to get inside the tiny holes and crevices. 

Be sure to start with low grit sandpaper, around 120 grit, and work your way up to a max of 2000 grit. This ensures a smooth finish without erasing any of the details. 

Also, when working with PLA prints, remember to use wet sanding. PLAs have a low melting point, and the friction from dry sanding can generate heat, causing it to become gooey and lose its structure. 

It’s important to use smooth circular motions when sanding to avoid applying too much pressure on a particular spot. Additionally, sand both with and against the grain to get a smoother finish. 

Understandably, the overall sanding process can get a bit monotonous. However, you must fight any urge to use a Dremel or any electric tool. These generally create too much heat from friction, which will result in the mini melting or disfiguring. 

Pro Tip: Once you’re done sanding, rinse the mini to wash away leftover debris. After drying it, apply a light coat of primer. This helps reveal any leftover irregularities, which you can then sand out following the same method. 

5. Smoothen the Miniature Using Post-Processing Techniques

A good sanding should help clear out most irregularities and clean up your miniatures (minis). 

However, if you want to make your miniatures look even better, you can utilize some of the post-processing techniques discussed here: 

• Use vapor smoothing on ABS prints.
• Use polyurethane to smooth layer lines and rougher prints. 
• Apply a coat of clear spray paint. 

Let’s go over each of these methods in more detail. 

Use Vapor Smoothing on ABS Prints

If your miniatures (minis) are made using ABS material, you can use the technique known as vapor smoothing. This gets a professional-grade shine out of your prints, almost as if they were injection molded plastic. 

This is due to the unique property that ABS prints have, causing them to melt around acetone vapors. Essentially, when the ABS prints come in contact with acetone vapors, the exterior surface dissolves, removing all the irregularities and leaving a smooth and glossy finish. 

There are dedicated machines you can use to vapor smooth your minis, but it can also be easily done manually in the following manner: 

1. Find a container (with a lid) large enough to accommodate your mini.
2. Dampen a piece of cloth or tissue and in acetone. 
3. Hang the cloth over the walls of a container with the mini inside. 
4. Cover the container to prevent the vapor from escaping and leave to sit. 
5. After some time, you’ll notice your miniature has gotten shiny. It means that the vapor smoothing has worked successfully, and you can remove the mini from the container. 

Warning: Acetone vapor is toxic and flammable. Only use in a well-ventilated room and wear a gas mask when handling. 

Use Polyurethane To Smoothen Layer Lines & Rougher Prints

One of the biggest problems with FDM printed miniatures is that you’ll end up with a stair-stepping effect. This gives the miniatures (minis) a rugged and unpolished look. 

It’s perfectly fine if that’s what you’re going for; but if not, you can easily smoothen these layer lines with the help of a little polyurethane. The compound sticks to the rougher surfaces, fills in any small gaps and imperfections, and ultimately gives the mini a cleaner and smoother look when dry. 

To apply the polyurethane: 

1. Use a small brush to coat a thin layer of polyurethane over the rough areas of the mini. It’s essential to apply a thin coat, so only the irregularities are covered up, not any details.
2. Stick the brush inside the areas where polyurethane is pooling and spread it out evenly across your mini. The compound tends to pool up and gather in holes and crevices. 
3. Once you’re done applying the coating, leave it to dry. 
4. If desired, follow with a light sanding for a smoother, more polished finish. 

It’s likely you’ve heard some people use epoxy for this exact same effect. However, I recommend using polyurethane because it’s much more flexible and elastic. As such, the end result becomes tougher and more scratch-resistant compared to epoxy coatings, which are generally more brittle. 

Apply a Coat of Clear Spray Paint

For SLA printed miniatures (minis), you can apply a coat of clear spray paint as a part of the post-processing. 

It’s a great way to clean the miniature by hiding minor blemishes and giving the mini a smoother look. Another advantage of applying spray paint is that it helps protect the mini from gradual yellowing, which is a common problem with resin prints. 

Note: Before you start spray painting your minis, make sure it’s adequately sanded and smoothened, or else the spray paint might end up highlighting the irregularities. 

For the best results, use these tips for spray painting miniatures: 

• Place mini(s) on a rotating platform for spraying to easily reach all sides. 
• Hold spray about 1 foot (30.5 cm) to ensure even application and prevent drips.
• Spray in short, even strokes.  
• Apply multiple light coats instead of one heavy coat for quality control. Keep in mind that it’s always easier to apply an extra coat of paint than to remove a layer. 

Warning: Spray paints are toxic. Always wear appropriate gear like a respirator and rubber gloves when using it. 

Key Takeaways

You can easily clean your 3D printed miniatures by following a step-by-step process: 

1. Wash the miniatures in an isopropyl alcohol bath to remove any uncured resin or leftover loose materials. 
2. Removing the larger, unnecessary structures, like rafts and supports. 
3. Clean up the smaller protrusions, strings, support marks, and surface-level irregularities.
4. Finish the clean-up process with a thorough sanding to smooth out any rough parts, or use post-processing techniques, like vapor smoothing and polyurethane coating, for a more polished look.