How to 3D Print Models With a Mirror Finish

Are you looking to get a super smooth mirror-like finish on your prints? Taking the time to polish all of your work can make it look more professional. Plus, you’ll be happier with the final results- no matter what you’re printing. 

Here’s how to 3D print models with a mirror finish:

1. Smooth the print with Acetone.
2. Sand the print with fine sandpaper.
3. Apply a liquid metal polish or metal powder.
4. Polish with fine steel wool.

The process is straightforward, even if the final results look complicated, so don’t feel overwhelmed. If you want to learn the best methods to give your final 3D prints a mirror finish, make sure to continue reading! I’ve included everything on the subject below.

1. Smooth the Print With Acetone

When you want a mirror finish on your prints, you need to make sure the print is first as smooth as possible. You can’t give it a mirror finish right off the printing bed. The easiest way to smooth it is to use Acetone. However, not all types of material are compatible with it.

For example, Acetone works well with ABS material, giving it that smooth and shiny finish you want. Whereas with PLA because the chemical will cause the print to melt.

Additionally, it’s important to work with this chemical in an area with the proper ventilation and avoid breathing it in.

To smooth a 3D print made from ABS material using Acetone, follow these simple steps:

1. Place your 3D print in a container not made with ABS, such as glass
2. Pour Acetone over the print inside until the liquid covers the print thoroughly. 
3. Check on the print every few minutes until finished.

At the most, many prints will only need to be submerged for 30 minutes. If you leave prints submerged for too long, the Acetone will wear away all of the detail in your print.

2. Sand the Print With Fine Sandpaper

If you’re using a material that can’t be smoothed out with Acetone, such as PLA, you’ll need to use sandpaper instead to create a mirror finish. Sanding must be done by hand and not with an electric sander, as it would be too harsh on the print and could even melt it.

For sanding 3D prints, you’ll need multiple grits of sandpaper. Start with a very fine option, then work your way up to higher grit levels for the smoothest possible finish. This is the best way to make the print look glossy. 

For example, start with an extremely fine grit 200. Then use 400, 600, 800, 1000- up to 3,000. Indeed, this does take a long time and a lot of effort, but you’re guaranteed to get amazing results with your print.

As you sand, take care not to remove the small details. As you use more grit, the sanding process gets quicker. Just be sure to smooth each layer as much as possible before moving on.

3. Apply a Liquid Metal Polish or Metal Powder

Next, you’ll need to polish your prints. The more time you can spend on this step, the better. Also, the more sanded your print, the better the polish looks.

You can use two types of polish: liquid or metal powder. Liquid metal polish is considered the easiest option. Alternatively, you can use a metal powder polish, available in copper, bronze, and iron.

Many experts recommend using Brasso polish (available on Amazon.com) because it provides a brilliant, long-lasting shine on various metal surfaces.

Here’s how to apply a liquid metal finish to your print: 

1. Apply using a soft rag when applying it to the print. Make sure to rub it softly.
2. Rub it in small, slow circles. 
3. Allow print to dry and add another layer of polish–At this stage, your print will look a lot shinier but not quite mirror-like yet. 
4. Take the clean side of the cloth and buff out the polish until you get the amount of shine you want. 

Here’s how to apply a powder metal finish to your print:

1. Mix the powder with glue using a notecard or wooden stick. Use two parts of the powder mixed with one part glue. (Note: you can even use Elmer’s glue and get great results.) Ensure the powder mixes with the glue thoroughly to avoid dry patches on your print. 
2. Spread the paste over your print using a knife or notecard. Take care to apply it in thin layers. 
3. Give the coat time to dry, and then add another layer. You may wish to give your powder mixture a good stir to ensure the glue hasn’t begun to dry up.

4. Polish With Fine Steel Wool

After allowing your print to dry for 24 hours, you should use steel wool on the print to polish it. Steel wool helps give the object a smooth and glossy surface. Take time to buff it without rubbing the powder off.

You can also buff the print with a soft cloth, although steel wool is better for using a powder metal. Use the cloth when you add a liquid metal to the print.

When To Use a Mirror Finish on Prints

This method makes your prints extremely glossy and metal-like. You can use the mirror finish whenever you want your print to look as glossy as possible and don’t mind taking the time to sand it out.

Overall, you can use the mirror finish whenever you want this kind of look! It’s popular for making figures and pieces for cosplay. However, it’s always an option, no matter what you happen to print.

Final Thoughts

To summarize, you’ll need flat, smooth surfaces on your prints if you want to make them look like a mirror. The mirror finish is a great technique to master, especially for printing metal-like objects.

Overall, it’s not tricky, so even beginners can quickly master it! The more time you use to sand and polish the print, the more mirror-like it will turn out. Make sure that you take your time with it for the best results.