Spray painting 3d prints

How to Prime and Paint 3D Printed Parts (With Video)

Primer

Primer is a special type of paint that adheres strongly to the part and provides a uniform surface for paint to bond with. Different primers have different uses. A spray-on primer is the best way to paint your printed parts because it quickly covers a surface with an even coating. Brush-on primers are available, but they are tricky to work with and better for fine touch ups. For best results, choose a primer and paint that are plastic compatible and from the same brand. We like Krylon and Montana (though both are thick formulas), but nothing really compares to Tamiya brand model paint - it goes on extremely thinly and evenly, preserving delicate surface details.

Rotary Tool

Because sometimes you want to sand fast. With interchangeable bits, rotary tools offer a variety of options for sanding and polishing parts. Drum sanding bits quickly sand down supports, while steel wire brushes smooth surface marks. Rotary tools are rough, so you will still need sandpaper for a smooth finish. There are plenty of great brands: Dremel and Craftsman are popular in the states, Proxxon in Europe. To avoid scorching your part, turn down the RPMs to the minimum (usually 500-1000) and use a light touch.

Hand Files

Not as clumsy or as random as a palm sander. A more elegant tool…for a more civilized age.

One of the most simple yet effective tools, a hand file removes supports and sands down surfaces. Using a firm grip, you can remove marks with more control than with a rotary tool. Keep a wire brush on hand and clean the file’s teeth often (otherwise plastic and resin will gum up teeth). Like a rotary tool, a hand file will leave a rough surface, so it’s best for removing the larger support marks.

Sand Paper

The most unglamourous tool in the shop, sandpaper has come light years in the last decade with the release of flexible sanding sheets. Available at home improvement stores, flexible sanding sheets last 15 times longer than paper ones. They don’t curl, puncture or crease.., and they hey can be used wet, which reduces dust and prevents buildup in the sanding tooth. Because they flex, they can easily reach small interior spaces and rounded surfaces.

Dust Removal

Even after wet sanding, some dust will remain. Remove buildup with water and a soft scrub brush (an old toothbrush works). For serious cleanup, an inexpensive sonicator can quickly remove fine particles caught in corners and cracks of a surface. If you work in an area with hard water, using deionized or distilled water will prevent spotting between painting.

Tack Cloth

Tack cloth is a soft, slightly sticky cotton cloth designed to remove remaining dust and leave a clean surface for painting. Let your model dry before using the tack cloth — the waxy surface does not work well with water.

Painting Block, Dowels & Drill

This simple trick will save you grief in the spray booth (we were excited when we saw this technique in a modelmaking how-to video by Adam Savage). By mounting your 3D print on a dowel (often you can use a preexisting hole in the part), you can quickly maneuver while spraying, allowing you to get to all sides and into the nooks and crannies of the part without creating any fingerprints. When you want to add an even coat to all sides of your model, this is pretty essential. We recommend ordering a variety of size of dowels. To minimize the hole size on a part, start with a small size and work your way up until the model feels firmly seated. Drill a corresponding hole in a block of wood or MDF and insert the part with the dowel - now you can keep the model hands free while spraying.

Safety Equipment

Spraypainting means working with airborne particulates and solvents, both of which pose health hazards. Remember to use a NIOSH approved respirator and work in a well ventilated workspace. While painting, wear nitrile gloves to avoid spraying paint on your hands and and also protect your model from fingerprints.

Ultimate Guide to Painting 3D Prints

Download the full Guide

as a PDF!

The simple post-processing techniques presented in this guide are an excellent way for professionals to create low-cost silicone molds, threaded inserts for enclosures, vacuum formed parts, and more.

If you’re an engineer or product designer creating concept models, a prop or set designer, artist, or an educator looking to add incorporate a bit more creativity into your classroom 3D printing activities, painting your models can be a great solution.

In this tutorial, we’ll show you how to create a nearly automotive quality paint job on any of your 3D printed objects.

Working time will vary depending on your model. Including drying time, the process shown took us about 6 hours from start to finish.

SUPPLIES

3D Print

Rubbing alcohol

Paper towels

Spray primer/filler

Spray paint

Hanging cord

80, 120, 240, 220, 1000 grit sandpaper

Needlenose pliers

Bondo

Sanding block & sandpaper

Gloves

Eye protection

Respiratory Mask

Need some of these products? We've curated an Amazon wish list for you.

STEP 1: PREPARE & PRINT MODEL

When preparing models for painting in MakerBot Print, keep in mind how your print settings will affect the quality of your paint job.

Consider: Print settings, print orientation, number of build plates

Surfaces printed in the Z axis will have the smoothest surface finish.

Printing models in 100 micron layer resolution will result in a slightly smoother surface finish, but will take significantly longer.

If possible, avoid placing support material in places you intend to paint as they will require more post processing to remove completely.

Supplies used: Needle-nose pliers or flush cutters

After you remove your print from the build plate of your printer, you will need to remove any raft or support material.

A. Remove prints from the build plate

B. Remove rafts

C. Remove large pieces of support

D. Approach smaller pieces and fine details

Supplies used: Sanding block, electric sander, 80,120, 240, 400, & 1000 grit sandpaper, Cyanoacrylate glue (super glue), Bondo

For the highest quality paint surface, an optional next step is to sand your model.

Make sure to wear eye protection, gloves, and a respiratory mask.

A. Dry sand the model using 80-240 grit sandpaper

B. Wet sand the model using 400 & 1000 grit sandpaper

C. Glue the parts of your model together

D. Apply filler to any gaps or blemish in your model and sand once dry

Find more detailed information here on gluing and sanding.

The 2021 Guide to 3D Printing Materials

Learn about polymers, composites, and metals all available for 3D Printing!

Supplies used: Hanging cord

Once your model is ready for painting - hang it in an open, dust free space with plenty of ventilation. This will allow you to paint all surfaces evenly without having to handle the model while paint is drying.

A. Tie hanging cord around the model

B. Hang the model in an open room with a tarp

STEP 5: PRIMER/FILLER

Whether you have chosen to sand your model and apply filler or you are simply painting a rough PLA model printed at high resolution, a few layers of primer/filler will fill any small surface imperfections before painting.

Primer filler is a high build spray filler that comes in aerosol form and can be purchased at most local hardware stores.

Before spraying remember to wear gloves, eye protection, and a respiratory mask.

BE SURE TO:

Shake well before use
Use wide strokes beginning and ending in space outside of the model
Hold the can 10-12 inches from the model
Paint in thin layers using a misting technique

AVOID:

Painting in thick layers
Holding the can in any spot for a long time
Holding the can too close to the model

Once you’ve sprayed 2-3 layers of primer/filler, allow your model to dry for 30-40 minutes.

STEP 7: SAND

A. Lightly sand your model with 1000 grit sandpaper (dry). This will smooth the surface of the model as the primer filler tends to create a rough surface texture similar to sandpaper.

B. Evaluate for quality.

C. If there are still surface imperfections you would like to smooth, continue to apply consecutive layers of primer/filler, and sand.

Once you are happy with the model surface, move on to painting.

STEP 8: PAINT

When choosing paint, you typically have a large degree of freedom as to which color and type of paint you use. Make sure to pick something that adheres well to plastic.

A. Choose a paint

B. Test for color in an inconspicuous location before painting the entire model

C. Let the paint sit overnight to cure

TIP:

Typically the paint will be dry to touch within an hour or so, and ready to polish within 24-48 hours.

If you’d like to protect the surface of your painted model, you can also apply a thin clear coat at this point.

In the end, you’re left with a beautiful painted model ready for approval presentation, enhanced for sets or galleries, optimized for better classroom learning, or simply improved for better innovation.

Here you can see just how far we have come.

Visit one of our other applications pages for tips on how to take your print even further.

We recommend that you visit our pages on:

Gluing
Sanding
Inserts

Last but not least, remember to share your work with us on Thingiverse and social media @MakerBot.

We can’t wait to see what you make!

Hair Dryer Shell
Ferro
10/2/2015
https://grabcad.com/library/hair-dryer-shell-1

Cold spray 3D printing research receives a grant from the European Space Agency

NASA's Jet Propulsion Laboratory is already applying state-of-the-art 3D printing technology to develop metal components from complex alloys. Trinity College Dublin has received impressive funding from the European Space Agency (ESA) to do the same job using innovative 3D printing technology. According to The Irish Times, Trinity College has received a €500,000 grant to develop a new cold spray technology for 3D printing metal parts. nine0003

An innovative cold spray method allows the 3D printer to print complex metal parts at room temperature. This technology allows layers of metal components to be bonded to each other without heating, thus preventing parts from being damaged and distorted at high temperatures. In addition to making it possible to 3D print complex parts as a whole, cold spraying also makes it easier to fuse metals with different chemical and physical properties. nine0003

The same results can be achieved in the course of development at NASA's Jet Propulsion Laboratory. The head of the project, Professor Rocco Lupoi, explains: “One of the parts of the resulting component can have one set of properties, while another part of the same element can have another. You can produce a part of any shape and combine materials in it in any order, improving the result in accordance with the requirements.

Lupoi adds that cold spray 3D printing does not pollute the atmosphere or use toxic materials. Instead, the process uses helium in gaseous form, which transports metal particles at 2,462 km/h, twice the speed of sound. nine0003

The professor says: “Normally, the process of manufacturing parts begins with a large piece of metal, which is gradually reduced during processing to the required size and shape. Cold spray works like a paint sprayer, applying material layer by layer to create the desired shape. The whole process takes a matter of seconds. Gases are accelerated to supersonic speeds, and the particles introduced into the gas and moving with it are also accelerated to supersonic speeds. The material particles move so fast that they penetrate the surface of the part and fuse instantly, so that, for example, you can produce an object five millimeters thick in a matter of seconds, a thousand times faster than with other methods.” nine0003

Although cold spray technology has been known for about a decade and used to create metal spray, it was considered too expensive to use in 3D printing of whole parts, due to the cost of helium. Helium allows for the high sputtering speed required to bond the metal layers. “If you want to achieve high speeds, you need to use helium because it is a very light gas. However, helium is an extremely expensive material, so with a relatively simple process, costs can be extremely high,” explains Lupoi. nine0003

In addition to the high costs associated with cold spray technology, its application in 3D printing is still in its early stages. In this regard, the method does not yet achieve an accuracy that meets the high standards of the aerospace industry. “This technology allows you to create metal parts using 3D printing, but an element of complex design can cost a million euros. The concept that we are developing in the framework of this project is especially aimed at solving technological difficulties of this kind,” adds the professor. nine0003

Professor Lupoi will be working on the project with other Trinity College professors as well as ESA staff. Their goal is to reduce costs and improve the quality of cold spray. “This is an interesting and challenging project, but we have a detailed technical plan approved by the ESA, according to which we must solve the tasks within four years,” the professor summed up.

Tags: Cold spray 3D printing, European Space Agency, Rocco Lupoi, Trinity College

Steel 3D printing - a quick guide

Any metal 3D printing technology can print with steel. This is the most popular material. But which steel grades and which technology is best for your application? Will printed steel parts really be as strong and durable as traditionally made parts? nine0003

Let's see how a 3D printed steel part is revolutionizing manufacturing and opening doors to new applications in aerospace, medical equipment, automotive, tool making, heavy industry, architecture and more. In addition, more affordable desktop printers are expanding the scope and scope of real steel 3D printed parts.

Strength of steel printed parts. nine0035 Cast steel part (left), 3D printed version (center). On the right, a fully 3D printed hinge requires no assembly. (Source: Desktop Metal)

The most common question when it comes to a 3D printed metal model is "Will it be as strong as a forged or cast part?" ?". The short answer is yes... and no.

3D printed steel parts can be just as strong, and sometimes even stronger, than those made in the traditional way. It depends on many factors such as: end use, type of steel, choice of 3D printing method, post-processing and shape of the part. Also, the comparison depends on which of the strength characteristics you focus on: tensile strength, static load strength, fatigue strength, etc. nine0003

Parts printed from steel are used in the aerospace industry, for the military, and also, for example, for the manufacture of a footbridge, shown below. Therefore, the strength of printed products is beyond doubt, but let's take a closer look.

Queen Maxima of the Netherlands officially opens a 3D printed metal bridge. Photo by Adriaande Groot (Source: MX3D)

A 3D printed or laser powder sintered (LPBF) steel part has a finer grain structure than cast metal products. This provides better tensile strength characteristics, but in other respects the cast parts are currently still stronger. Most often, LPBF 3D printing is used to replace cast components, but in some cases, 3D printed components can replace forged parts. nine0003

One study showed that, under certain conditions, stainless steel parts made using LPBF 3D printers were three times stronger than parts made from the same steel using the traditional method.

In experiments comparing 3D printed steel parts to traditionally made steel parts, researchers create identical parts using two methods and compare their performance. However, head-to-head comparison of details is only part of the big picture. nine0003

The main advantage of printing with steel is not only its strength, but also the unique ability to create internal channels and lattice fillings in parts, which is impossible using traditional manufacturing methods. Metal 3D printing makes it possible to produce parts faster than traditional production, since this method does not require the use of special equipment and tools, it allows you to create assemblies as a whole, eliminating the need for subsequent assembly and welding. Designing a printed part usually means that less metal is needed to make it, and therefore less weight, for the same strength. nine0003 MX3D Wire Arc Additive Manufacturing (WAAM) printed steel architectural support (Source: MX3D)

Steel 3D printing is also more stable and cost effective as it reduces waste. When using subtractive manufacturing methods, such as CNC machining, you make a part by cutting it out of a large one, with a lot of waste. With additive manufacturing, you only use the material you need to make the finished product. nine0003

Steel 3D printing is not intended to replace traditional methods in all areas, but it may be a better choice for a wide range of applications. Particularly when the required parts are unique and designed for specific applications, such as rocket engines, racing cars or the oil and gas industry. 3D printing is the fastest and most flexible technology for mass production and prototype production. For military and industrial applications, steel 3D printing is a faster and more efficient way to create individual parts for vehicles and machines. Stainless steel 3D printing is rapidly finding applications in medicine to create unique surgical instruments and implants. nine0003

If you know what characteristics your final product should have (tensile strength, compressive strength, hardness, density, etc.), then all these parameters can be incorporated into the product at the production stage.

Types of steel for 3D printing

Metal powder is the most used metal material for 3D printing (Source: GKN Additive)

There are thousands of different grades of steels and alloys with different mechanical properties, used in traditional manufacturing but in 3D printing there are only a few dozen of them, and some of them are unique, created specifically for this technology. Among the steel options, the following can be distinguished:

Stainless steel (316L, 304L , 17-4PH, 15-5PH, 420, 254, Ph2, GP1, 630, 410).
Tool steel (D2, M2, h23, h21, MS1, 1.2709).
Low alloy steel (4140).
Structural alloyed (20MnCr5).

Recently, unique alloys have been developed specifically for 3D printing to solve the problems that come with traditional manufacturing methods. nine0003

For example, 3D printer manufacturer Desktop Metal released a patented stainless steel in 2022 that the company says combines the tensile strength, ductility, and corrosion resistance of 13-8 PH stainless steel, combined with the hardness low alloy steel like 4140. The company says customers can go to market with this material and skip the galvanizing step to protect products from corrosion.

ExOne offers two special blends of steel and bronze that the company says allows 3D printed steel parts to achieve increased corrosion resistance while being easy to machine and polish. nine0003

While most of the metal powders used in 3D printing are similar to those used for other manufacturing methods, their numbers are on the rise as more companies adopt the technology. Some metal powder manufacturers, such as GKN, also make custom powders for specific 3D printing applications.

How to print with steel

The strength, properties, and applications of 3D printed steel products largely depend on which 3D printing technology you use. Some methods produce stronger parts, other methods provide better hardness or abrasion resistance, and some technologies are simply very fast. nine0003

Below are the main metal 3D printing methods, their properties and some of the most common application examples.

FDM printing

BCN3D's Epsilon printer extrudes metal filament from stainless steel (Source: BCN3D) as more printer manufacturers certify metallic filaments for use on their printers, such as Ultimaker, BCN3D, Makerbot, Raise3D. Raise3D has recently released a complete metal printing suite - Metalfuse (3D printer, debinding oven and sintering oven). This method is still much more popular for printing plastics, but with new plastic filaments filled with stainless steel powder, strong metal parts can be produced.

nine0003

FDM media was once limited to thermoplastics. Companies like BASF Forward AM and The Virtual Foundry now offer metal filaments that can be used on almost any FDM printer as long as it has a hardened steel nozzle for abrasive media.

These materials are approximately 80% metal and 20% plastic. After printing, the post-processing process removes the plastic, resulting in 100% metal parts. nine0003

Due to the removal of the bonding plastic, FDM metal parts shrink during post-processing. The amount of shrinkage is constant and can be taken into account in CAD systems, which allows to obtain relatively accurate finished parts.

Forward AM's 316L Stainless Steel Ultrafuse filament produces finished parts with material properties that the company claims are comparable to injection molded metal parts. nine0003 (Source: BCN3D)

While 3D printing with metallic materials may not be suitable for demanding applications such as aerospace, the economics of producing simple metal components without critical loads on an affordable FDM printer can outweigh the impossibility of applying them in some areas.

Metal prototype parts and finished parts that will not be subjected to extreme stress are ideal uses for this technology. nine0003

Bound Metal Deposition (BMD)

Desktop Metal's Studio System 3D printer used bonded metal bars that were extruded layer by layer to form a metal part (Source: Desktop Metal)

Similar to FDM, Metal mesh deposition method (BMD) or bonded powder extrusion (BPE) is a 3D printing process based on extrusion. This method uses bonded metal rods or bonded powdered metal filaments, which consist of a much higher percentage of metal powder than the filaments used in FDM. As with FDM, post-treatment to remove the binder and heat treatment in a final sintering oven are required. nine0003

There are only a few 3D printers using this method such as Desktop Metal, Markforged and more recently 3DGence, but more companies are entering this market, so stay tuned. These printers are valued as a convenient solution for office 3D metal printing, they are more expensive than most FDM printers, but cheaper than the powder-based metal 3D printing technologies described below.

These printers use their own proprietary filament. Desktop Metal and Markforged offer four types of steel. nine0003

Ideal niches for this technology are metal prototype parts, where it is necessary to test the functionality of a part before mass production using traditional methods. Popular applications are molds, punching dies, nozzles, impellers, fasteners and heat exchangers.

For example, Shukla Medical uses Markforged's Metal X printer to print steel prototypes of its orthopedic implant removal instruments. nine0003

Laser powder sintering.

Laser powder sintering technology uses one or more lasers to melt powdered metal into a desired shape layer by layer (Source: GE Additive) metal printing. This technology is used by 80% of all metal 3D printers on the market.

This method uses powerful lasers to selectively sinter metal powder layer by layer. nine0003

LPBF 3D printers are available in a wide range of sizes, prices and laser powers. These and other characteristics affect the properties of the finished part, print speed and other parameters of the finished products.

Steel and steel alloys are the most popular material for LPBF equipment and, unlike FDM and BMD, metal powders are commercially available as they are most commonly used in traditional production methods.

LPBF is a technology that maximizes the quality of a 3D printed part. Applications include aerospace components such as monolithic thrust chambers, rocket engine components and heat exchangers, molds, tools and other applications, as well as high wear parts and surgical instruments. nine0003

Binder Jetting

Binder Jetting 3D printing technology uses powdered metal and a binder to form metal parts (Sorrce: ExOne) binder, and not with a laser. During post-processing, the binder is removed.

Binder application stands out for its high printing speed compared to other 3D printing methods or traditional manufacturing, and metal parts made with this technology have material properties equivalent to those made by metal injection molding. nine0003

The number of manufacturers producing metal-bonded inkjet 3D printers is much smaller than that of LPBF machines. Leading manufacturers include ExOne, Desktop Metal, Digital Metal, GE Additive and HP.

Binder blasting is ideal for medium to high volume production of metal tools and spare parts.

In fact, HP claims that its Metal Jet 3D printer was designed specifically for mass production of 316L stainless steel products. HP has partnered with Parmatech to produce metal parts for the medical industry. Pennsylvania-based ExOne uses this technology to manufacture hard metal cutting tools and tool steels. nine0003

Electron Beam Melting (EBM)

(Source: GE Additive)

Electron Beam Melting (EBM) is another powder cladding technology. It works in a similar way to selective laser melting (SLM), but instead of using a laser as the energy source, it uses a much more powerful beam of charged particles.

The recoater moves the powder onto the printing plate and an electron beam selectively melts each layer of powder. After each layer is printed, the plate is lowered and another one is applied on top of the previous layer. nine0003

EBM can be much faster than SLM, but SLM produces smoother and more accurate pieces. The electron beam is wider than the laser beam, so EBM cannot produce the same precise parts as SLM. Another difference is that the manufacturing process takes place in a vacuum chamber, which reduces the amount of impurities in the material that can lead to defects. That is why EBM is often chosen for printing components for the aerospace, automotive, defense, petrochemical and medical implant industries. nine0003

Titanium is the most popular metal for most EBM applications, however steel can be used.

Cold Spray

(Source: Impact Innovations)

Cold spray 3D printing is done by injecting metal powders through a jet nozzle into a supersonic stream of pressurized gases such as air, nitrogen or helium. The process is called "cold" because the metal particles do not melt, but hit the metal substrate and adhere to its surface during the so-called plastic deformation. nine0003

Cold spray printed products are not prone to porosity, thermal cracking and other defects associated with melt-based technologies. This method has several advantages over other production methods. The technology is used in the military and aerospace industries around the world. For example, the US Army uses cold spray to repair the mounts of a worn Bradley 25mm steel turret gun.

In the automotive industry, cold spray steel is used for crash repairs because the high strength steel substrates in cars can be susceptible to thermal repair methods such as welding. nine0003

Direct Energy Deposition (DED) and Wire Arc Additive Manufacturing (WAAM)

MX3D WAAM Steel Parts (Source: MX3D)

Direct Energy Deposition (DED) uses welding powder or wire that enters through a nozzle and is fed into the power source to melt the metal. A melt region is created and applied to the substrate. DED is a new process, reminiscent of an old building technology known as "cladding", in which a coating is applied to a substrate, often for thermal insulation or weather resistance. DED is useful for fabricating large objects as a whole, as well as complex geometries that require extensive machining. DED can get such parts much closer to finished than traditional CNC machining. nine0003

Because DED uses a coating process, it can be used to add complex geometries to existing steel parts, thus combining complexity with cost reduction. For example, the French company AddUp advertises a rocket nozzle that uses a preformed large 304 stainless steel hopper cone printed with an isogrid structure, usually made from a larger piece by traditional methods.

A technology related to DED is wire-arc additive manufacturing (WAAM). Instead of powder, WAAM uses a metal wire that is melted by an electric arc. The process is controlled by robotic arms. WAAM is also capable of producing large-sized metal parts, as demonstrated by the Dutch company MX3D and its nine thousand-pound 41-foot stainless steel bridge in Amsterdam, as well as an oil and gas equipment repair part, proving that parts can be made in the field. nine0003

Micro 3D printing

Micro parts printed from steel (Source: 3D MicroPrint)

Micro scale additive manufacturing, or micro 3D printing, can produce products with a resolution of a few microns (or less).