What Type of Primer Should You Use for 3D Printed Figures

Primer is an important step in achieving a smooth and high-quality finish on 3D printed models, especially figurines and statues. Choosing the right primer not only improves paint adhesion, but also improves the overall visual effect of the model. The following will provide you with a detailed analysis of the types of primers, applicable scenarios and usage tips to help you choose the most suitable primer for your 3D printed models.

Source:https://justpaint.org/hand-painting-3d-prints-with-acrylics/

Why do you need to prime your 3D printed models?

3D printed models usually have delamination lines or small flaws on the surface. The main functions of primer are as follows:

Filling defects: Filling the print layer lines and tiny holes to make the surface smoother.

Enhancing adhesion: Provide a good adhesion base for subsequent paint to avoid paint peeling or uneven color.

Detecting defects: Primers reveal surface problems, such as unpolished rough areas.

Common types of primers and their characteristics

Acrylic primers

Acrylic primers are an environmentally friendly water-based paint that is very suitable for PLA, ABS and photosensitive resin prints. It is non-toxic and odorless, suitable for indoor use, dries quickly and is easy to operate. Acrylic primers are available in a variety of colors, which can be flexibly matched with different painting schemes. However, due to its weak filling ability, repairing layer lines or deep defects may require multiple coatings.

Spray primer

Spray primer is in aerosol form and is suitable for models with complex structures or large sizes. Its advantages are uniform spraying, ability to cover every detail of the model, fast painting speed and convenient operation. However, when using spray primer, attention should be paid to environmental ventilation to avoid inhalation of aerosol. In addition, the amount of spraying should be carefully controlled during the spraying process to avoid excessive material waste. JLC3DP provides spray painting services, and you can check the supported colors through this article: https://jlc3dp.com/help/article/questions-about-jlc3dp-spray-painting

Products using JLC3DP spray painting

Epoxy primer

Epoxy primer is known for its high filling ability and sturdiness. It is an ideal choice for models that require high-strength coatings, especially resin prints. It can effectively cover layer lines or other obvious defects, form a smooth base layer, and improve the painting effect. However, epoxy primers have a long drying time, and you need to wait patiently before use. Moreover, polishing after painting is relatively difficult, which puts higher technical requirements on the operator.

Enamel primer

Enamel primer is a solvent-based oil-based paint that forms a hard, stain-resistant coating with a smooth, high-gloss finish. It is often used for outdoor models or high-wear environments. Enamel primer has excellent durability, but it takes a long time to dry. It needs to be used in a well-ventilated environment to avoid inhaling irritating odors. It takes patience to achieve the desired effect during use.

3D Printing Model Primer Usage Steps

1. Clean the Model Surface

Before applying primer, make sure the model surface is clean and flat. Use 220–400 grit fine sandpaper to lightly sand the model to remove obvious layer lines or rough areas. Then, wipe the surface with isopropyl alcohol to remove all dust and grease to ensure that the primer can adhere evenly.

2. Fill the hole

If there are large cracks or holes on the model surface, use a filler (such as epoxy resin or putty) to repair them. After the filler is completely dry, use sandpaper to sand the filled area until it is flush with the surface.

Source: https://hackaday.com/tag/filler/

3. Choose the right primer

Choose the right primer type according to the model material and the environment in which it is used. For example, acrylic primers are often chosen for plastic models, while epoxy primers or other specialized coatings are more suitable for metal models.

4. Applying Primer

Depending on the type of primer you choose, you will need to apply it in different ways. For spray primers, hold the nozzle 15–20 cm away from the model and spray evenly to avoid paint accumulation or dripping; for acrylic primers, apply with a soft-bristled brush to ensure that the coating is even and there are no obvious brush marks. Applying multiple thin coats will give better results than applying a thick coat once, without covering up details.

5. Drying and Inspecting

After the primer is completely dry, check that the surface of the model is even. Acrylic primers usually take about 30 minutes to dry, while epoxy primers may take several hours to dry. If you find that the primer is uneven or there are still imperfections on the surface, you can re-sand and apply additional coats.

6. Repeat Coating (Optional)

For a more perfect finish, you can lightly sand the model and apply a new coat of primer after each coat has dried. This step can be repeated several times until the desired effect is achieved.

7. Sealing

After the primer is applied, you can choose to cover the surface with varnish or other sealants to enhance the protection effect and provide a better foundation for subsequent coloring.

Related article: https://jlc3dp.com/blog/3d-printing-spray-painting-process-revealed

Choosing the right primer for the 3D printed model is an important part of improving the final painting effect. At the same time, mastering the application skills and steps of the primer can make the painting process of the model smoother and the effect more ideal. If you have more requirements for the painting of 3D printed models, JLC3DP provides a one-stop solution from high-precision printing to post-processing services to help you achieve high-quality output from design to finished product. Welcome to visit our Help Center to learn more about professional services and technical support for 3D printing.