2k Primer

SQUADRON COLORS 2K PRIMERS

Building a Smooth, Durable Foundation

Squadron Colors 2K Primers are activated two-component coatings designed to provide an exceptionally smooth, durable foundation for your paint finish.

Unlike our standard 1K primers, Squadron Colors 2K Primers must be mixed with their supplied Activator before spraying. Once mixed, a chemical curing process begins, creating a tough, durable surface that provides an excellent foundation for subsequent paint and finishing steps.

Different 2K primer colors may be used depending on the project, the colors being applied over them, and the final effect you're trying to achieve.

When using Squadron Colors 2K Gloss Black Primer, its smooth, high-gloss surface makes it especially well suited as a foundation for highly reflective finishes such as Squadron Colors Chrome and Polished Aluminum.

This guide will take you through surface preparation, mixing, application, flash times, curing, cleanup, and troubleshooting.

1. WHAT DOES “2K” MEAN?

“2K” means two-component.

The system consists of:

2K Primer + Activator

The Primer and Activator are stored separately. Once they are mixed together, a chemical curing reaction begins.

This is different from our standard 1K lacquer products, which do not require an Activator.

Because curing begins once the two components are combined, only mix the amount you expect to use during your painting session.

Never pour activated material back into the original Primer or Activator containers.

2. SURFACE PREPARATION

A quality primer finish begins with proper surface preparation.

Before spraying:

Complete major assembly and seam work.
Fill gaps and imperfections where necessary.
Sand seams, filler, scratches, and mold lines smooth.
Remove sanding dust and residue.
Make sure the model is clean and completely dry.
Remove fingerprints, oils, and other contamination.

Remember that primer is not a substitute for proper surface preparation.

A smooth surface underneath the primer will help produce a smoother finished result.

This becomes especially important when using 2K Gloss Black Primer beneath Chrome or Polished Aluminum, where imperfections in the underlying surface can remain visible through the highly reflective final finish.

3. MIX THE PRIMER BEFORE ADDING ACTIVATOR

IMPORTANT — MIX THE PRIMER FIRST

Pigments and other components can settle during storage.

Before measuring or adding Activator, shake the Primer bottle until the mixing ball inside is moving freely, then continue shaking thoroughly to make sure all settled material has been completely reincorporated.

Simply hearing the mixing ball does not necessarily mean the Primer is completely mixed.

Take the extra time to mix it thoroughly.

Only after the Primer has been completely mixed should you measure and combine it with the Activator.

4. MIXING RATIO — 4:1

Squadron Colors 2K Primer is mixed:

4 PARTS PRIMER : 1 PART ACTIVATOR

The ratio is measured by volume.

For example:

4 mL Primer + 1 mL Activator = 5 mL mixed

8 mL Primer + 2 mL Activator = 10 mL mixed

12 mL Primer + 3 mL Activator = 15 mL mixed

Measure the two components accurately and mix them together thoroughly before spraying.

Only prepare the amount you expect to use during your painting session.

POT LIFE

Once the Primer and Activator have been mixed, the chemical curing process has begun.

The mixed Primer has a pot life of up to approximately 2 hours, but we recommend using the mixed material as soon as practical rather than allowing it to sit unnecessarily.

As the activated Primer progresses through its pot life, its spraying characteristics may begin to change.

Most importantly, clean your airbrush as soon as you have finished spraying. Once activated 2K Primer cures inside an airbrush, it can be extremely difficult to remove.

NEVER RETURN MIXED MATERIAL TO THE BOTTLE

Never return unused activated Primer to either the original Primer or Activator container.

5. AIRBRUSH SETUP

Start at approximately 20 PSI and increase or decrease air pressure as needed to achieve the desired spray pattern and finish.

There is no single perfect PSI setting for every modeler.

Airbrush design, needle/nozzle size, spraying distance, temperature, elevation, compressor setup, and individual spraying technique can all influence the ideal pressure.

Think of 20 PSI as a starting point — not a rule.

Before spraying your model, test the mixed Primer on a paint mule, plastic spoon, scrap material, or another suitable test surface.

Adjust your pressure and paint flow until the Primer atomizes smoothly and consistently.

6. USE A MOISTURE TRAP

A moisture/water trap is required when using an air compressor.

Compressing air creates condensation. Moisture can collect inside compressor tanks and air lines and may eventually reach the airbrush.

Water contamination can interfere with lacquer coatings and negatively affect both the spray pattern and finished surface.

Always make sure your moisture trap is installed, functioning properly, and drained as needed before spraying.

7. APPLYING 2K PRIMER

Squadron Colors 2K Primer is applied progressively rather than trying to achieve the entire finish in one heavy application.

COAT 1 — MEDIUM COAT

Apply a smooth, controlled medium coat.

Allow approximately 5–10 minutes of flash time.

COAT 2 — MEDIUM-TO-WET COAT

Apply a fuller medium-to-wet second coat while maintaining control of the surface.

Allow another 5–10 minutes of flash time.

COAT 3 — FINAL WET COAT

Apply a smooth, even wet coat to establish the final surface.

Avoid excessive application. Applying too much material can cause runs, sags, pooling, excessive buildup, or unnecessarily extend the curing process.

The objective is a smooth, even finish — not simply the heaviest coat possible.

8. WHAT DOES “FLASH” MEAN?

Flash time is the short waiting period between coats that allows solvents in the freshly applied coating to begin evaporating.

Giving each coat sufficient flash time helps prevent excessive solvent and material from becoming trapped underneath the next coat.

For Squadron Colors 2K Primer, allow approximately 5–10 minutes between coats under normal conditions.

Temperature, airflow, humidity, and the amount of material applied can affect actual flash time.

Don't rush the process.

9. AFTER THE FINAL COAT

After applying the final wet coat, allow approximately 15 minutes of flash time before beginning any accelerated curing process.

If you're not using accelerated curing, simply allow the Primer to cure naturally at room temperature.

Avoid touching or disturbing the freshly painted surface during this time.

Remember that the surface beginning to feel dry does not mean the Primer has completely cured.

10. WHAT IS ACCELERATED CURING?

NOTE: ACCELERATED CURING APPLIES ONLY TO SQUADRON COLORS 2K PRODUCTS THAT ARE MIXED WITH AN ACTIVATOR.

Accelerated curing simply means using controlled, gentle heat to speed up the chemical curing process of the activated 2K Primer.

ACCELERATED CURING IS OPTIONAL

Squadron Colors 2K Primer does not require accelerated curing. It will cure normally at room temperature without additional heat.

When curing naturally at room temperature, allow approximately 48–72 hours for a full cure before sanding or extensive handling.

If you choose to accelerate the curing process, a food dehydrator with adjustable temperature control can provide a controlled source of gentle heat.

USING A TEMPERATURE-CONTROLLED DEHYDRATOR

After applying the final wet coat of 2K Primer, allow it to flash for approximately 15 minutes before placing the model or parts into the dehydrator.

The 2K Primer may then be accelerated-cured for approximately:

60 MINUTES AT 120°F (49°C)

After the 60-minute curing cycle is complete, remove the model or parts from the heated environment and allow them to cool completely to room temperature before handling, sanding, or proceeding with additional finishing steps.

IMPORTANT — KNOW YOUR MODEL

120°F (49°C) is an accelerated-curing temperature for the coating. It does not mean that every model or modeling material can safely withstand that temperature.

Always make sure the model and all materials used in its construction can safely tolerate the selected temperature.

Excessive heat can warp, soften, distort, or otherwise damage:

Styrene plastic
Resin
3D-printed parts
Clear parts
Adhesives
Putty and fillers
Decals
Other model components

VERY IMPORTANT: If you're unsure whether your model or any of its components can safely tolerate the heat, do not use accelerated curing. Allow the 2K Primer to cure naturally at room temperature instead.

Never use open flames, heat guns, household ovens, or other uncontrolled heat sources for accelerated curing.

CURING QUICK REFERENCE

ROOM-TEMPERATURE CURE: Approximately 48–72 hours

ACCELERATED CURE: Final wet coat → 15-minute flash → 60 minutes at 120°F (49°C) → Cool completely to room temperature

Remember:

ACCELERATED CURING IS AN OPTION — NOT A REQUIREMENT.

IMPORTANT — HEAT DAMAGE WARNING

Accelerated curing is optional and is performed at the modeler's own discretion.

120°F (49°C) is the recommended accelerated-curing temperature for the coating. It is not a guarantee that the model, its components, or other materials used in its construction can safely withstand that temperature.

Before using a dehydrator or other temperature-controlled curing device, always verify that the model and all materials used in its construction are suitable for the selected temperature.

Styrene, resin, 3D-printed materials, clear parts, adhesives, putties, fillers, decals, aftermarket components, and other materials may react differently when exposed to heat. Actual temperatures inside curing devices may also vary from their displayed settings.

Squadron is not responsible for warping, distortion, melting, separation, finish damage, or other damage to models or components resulting from the use of heat or accelerated-curing equipment.

If you are uncertain whether your model can safely tolerate accelerated curing, allow the coating to cure naturally at room temperature instead.

Never use an open flame, heat gun, household oven, or other uncontrolled heat source for accelerated curing.

11. ROOM-TEMPERATURE CURING

If you're not using accelerated curing, allow the Primer to cure naturally at room temperature.

For a full room-temperature cure before sanding or extensive handling, allow approximately 48–72 hours.

Remember:

“DRY TO THE TOUCH” AND “FULLY CURED” ARE NOT THE SAME THING.

A surface may feel dry while the coating underneath is still curing.

Temperature, humidity, airflow, and the amount of material applied can all affect curing time.

When in doubt, give it more time.

Patience at this stage can help prevent fingerprints, surface damage, sanding problems, or other issues later in the finishing process.

12. USING 2K GLOSS BLACK WITH CHROME OR POLISHED ALUMINUM

When Squadron Colors 2K Gloss Black Primer is being used as the foundation for Squadron Colors Chrome or Polished Aluminum, the quality of the gloss-black surface is extremely important.

Highly reflective finishes reproduce the characteristics of the surface underneath them.

Before proceeding, the 2K Gloss Black should be:

Fully cured
Exceptionally smooth
Deep and glossy
Free from dust
Free from fingerprints
Free from oils and other contamination

CLEAN THE SURFACE BEFORE APPLYING THE REFLECTIVE FINISH

Once the 2K Gloss Black has fully cured, gently wash the surface using fragrance-free dish soap and water.

Rinse thoroughly.

We recommend using distilled water for the final rinse to help prevent minerals or water spots from being deposited on the surface.

Allow everything to dry completely.

From this point forward, avoid touching the prepared surface with bare fingers.

Then proceed using the instructions in our Squadron Colors Chrome & Polished Aluminum Guide.

13. INSPECTING THE FINISHED PRIMER

Once the Primer has cured, inspect the model carefully under good lighting.

Look for:

Dust or debris
Runs or sags
Surface texture
Visible seams
Sanding scratches
Gaps
Uneven filler
Other surface imperfections

Primer is one of your best opportunities to find problems before the final colors are applied.

If something needs correction, fix it now rather than hoping subsequent paint layers will hide it.

14. TROUBLESHOOTING and F.A.Q.

THE FINISH ISN'T SMOOTH

Check your air pressure, spraying distance, paint flow, surface preparation, and the amount of material being applied.

If the coating is arriving too dry, it may not have an opportunity to flow and level properly.

Always test adjustments before continuing on the model.

I HAVE RUNS OR SAGS

Too much material has likely accumulated in that area.

Don't immediately try to fix a run while the coating is still wet.

Allow the Primer to cure completely before attempting correction.

THERE'S DUST IN THE FINISH

Keep your spraying area, model, airbrush, and surrounding workspace as clean as practical.

Dust becomes particularly noticeable when you're trying to produce an exceptionally smooth surface.

THE PRIMER ISN'T SPRAYING CONSISTENTLY

First make sure the Primer was mixed thoroughly before the Activator was added.

Then check:

Air pressure
Airbrush cleanliness
Needle/nozzle condition
Moisture trap
Paint flow
Spray distance

If the activated Primer has been sitting for an extended period, remember that it is continuing to cure in the mixing cup and its spraying characteristics may change as it approaches the end of its pot life.

CAN I SAND IT AS SOON AS IT FEELS DRY?

Give the Primer adequate time to cure.

A coating can feel dry to the touch before it has fully cured underneath.

Sanding an insufficiently cured coating can produce poor results or damage the finish.

CAN I APPLY CHROME AS SOON AS THE GLOSS BLACK FEELS DRY?

Don't rush it.

For the best reflective result, the 2K Gloss Black foundation should be fully cured before Chrome or Polished Aluminum is applied.

CAN I APPLY SQUADRON COLORS ACRYLIC PAINT OVER THIS PRIMER?

Yes. Squadron Colors Acrylic Paint may be applied over Squadron Colors 2K Lacquer Primer after the primer has properly cured.

Make sure the primed surface is clean, dry, and free of dust, fingerprints, oils, and other contamination before applying the acrylic color.

15. QUICK REFERENCE

MIX

Mix Primer thoroughly → 4 Parts Primer + 1 Part Activator → Mix together thoroughly

POT LIFE

Up to approximately 2 hours — but use mixed material as soon as practical and clean your airbrush immediately after spraying.

SPRAY

Start around 20 PSI → Medium coat → 5–10 min. flash → Medium/wet coat → 5–10 min. flash → Final wet coat

CURE

Final coat → Approximately 15 min. flash → Allow to cure naturally OR use an appropriate controlled accelerated-curing method

ROOM-TEMPERATURE FULL CURE

Approximately 48–72 hours before sanding or extensive handling

REMEMBER

Only mix what you need. Never return activated material to the original containers.

16. CLEANUP — DO NOT WAIT

Clean your airbrush immediately after use with a quality lacquer thinner or lacquer airbrush cleaner.

Empty any remaining mixed material from the airbrush and flush thoroughly with lacquer thinner until it sprays clean.

For a more thorough cleaning, follow your airbrush manufacturer's instructions for disassembly and clean any remaining material from the needle, nozzle, paint cup, and other paint-contact areas.

IMPORTANT — DO NOT ALLOW ACTIVATED 2K PRIMER TO CURE INSIDE YOUR AIRBRUSH

Once the Primer and Activator have been mixed, the curing process has begun.

Even though the mixed material has a usable pot life, do not leave activated Primer sitting in your airbrush after you have finished painting.

Clean your airbrush thoroughly as soon as you have finished spraying.

Once activated 2K Primer has cured inside an airbrush, it can be extremely difficult to remove.

Never return mixed or used material to the original Primer or Activator containers.

17. SAFETY

Squadron Colors 2K Primer is intended for adult hobby use. Keep Away from Children.

2K coatings require additional care when mixing and spraying.

Contains flammable solvents and produces harmful vapors. Always use appropriate respiratory protection and adequate ventilation when mixing, spraying, and cleaning.

Avoid skin and eye contact and follow all safety information provided with the product.

Keep containers closed when not in use.

Keep away from heat, sparks, and open flame.

Always follow appropriate safety practices when spraying lacquer and activated 2K coatings.