Do you really need to Prime models?

One of the biggest questions I always see when people start painting their models is why do they need to prime. I mean the usual argument is that it requires equipment and buying a primer which costs more money. Much like the clear coat, primer is also important in the painting process.

If you don’t prime your models, the stickiness of the paint will be severely decreased. The leads to imbalanced paint in the finish or paint not sticking to the model which can cause bubbles. Furthermore, the primer protects the model itself from the oxidation of metals.

In this article, we are going to talk briefly about what happens when you don’t prime. Also, we will talk about what happens if you don’t prime plastic and diecast models before painting.

What happens if you don’t prime?

What happens if you don’t prime is that the paint’s adhesiveness will be decreased. This leads to lots of imperfection in the finished product including lines and bubbles made by the paint. This in turn makes the quality of your models look bad and costs you a lot more work than necessary.

Priming helps paint layers’ adhesiveness to the miniature model’s surfaces.

You will not get the same results in the absence of priming your models.

For tons of individuals within the modeling industry, priming models are taken into account as a requirement and a must-do act before applying any paint layer.

They know very well the after-effects without applying the prime layer.

But one must be vigilant to employ a skinny layer rather than a thick layer for creating the model base more robust and sturdier.

If you are not using primer on your miniature models, the paint will form a shell around your painted model and it will not be in a highly cohesive fashion.

This suggests that primer acts as intermediary support between your miniature model and paint layers.

If your painted model will get dropped from a particular height, you are going to see cracks, easily visible due to the paint layer’s bad adherence level onto the model’s surface and it also can peel off in chunks instantly.

Once the primer will be used on your miniature models, it will help the highest layers of paint to strengthen stickiness, and the paint layers will set better onto your primed model.

Your sales will be at high risk if you are not priming your miniature models because the customers might return your product after a bad experience or they even do not come later.

Priming will help your model’s appearance to be better and it will also look great after the primer job.

If you consider the competition in the plastic model industry, without using prime, your model will look terrible.

Primer establishes a strong relationship between the model’s surface and the layers of paint for which the survival period increases.

Additionally, the greasy material on any model can be easily escaped for better paint grip utilizing the prime’s teething characteristic onto the model’s surfaces.

To know more about the scientific side of priming, you may check out this article I’ve made. It talks about priming in a much deeper way going on its link between the paint and the models. Here is the article: Is priming necessary before painting?

But one question we need to ask ourselves is that what will happen if we don’t prime plastic and metals? We’ll find that out in the next section.

What happens if you paint plastic without primer?

If you don’t prime your plastic models, what happens is that the paint will have a hard time sticking to the model. The thing about plastic is it is not really good with adhering to paint. That’s why it is necessary to primer plastic models since it will act as the bridge between the plastic and paint.

We can find plastics everywhere around us. A lot of items can be found to be made out of plastic such as furniture, mobile phones cases, decoration pieces, mugs, and others.

Although there are different types of plastics used in making these things. It is really hard to find yourself in an area where there is no such thing as plastic or plastic-made items in your locality.

However, it is not an easy job to customize plastic material and give it a paint job compared to other materials such as wood, metal, and others.

Mostly, the paints will not stick to the plastic materials properly and there are high chances that the paint layers will crack off or peel off in just a short while.

This happens because there is nothing to support the plastic material to grip the paint layers.

Another important concern in painting plastic materials is the expected discolorations. So confusing!!! Then, what to do if you want to properly paint plastic materials and permanently?

Generally, primers are used to give plastic materials a good holding power for paint layers.

If you want to avoid primers, what option do you have?

There is this Rust-Oleum spray paint which is widely used for plastics to stick well and it is highly recommended by industry professionals.

However, you cannot use this spray paint on every type of plastic material since different plastics behave differently to paint jobs.

It is good enough for various kinds of plastics except for Polyethylene.

One can identify Polyethylene plastic as it is usually written on plastic materials in an arrowed triangle as “PET” in the middle with capital letters.

There will be no sanding or priming required to do this type of paint job on plastic materials but you have to ensure that these plastics do not move or bend so that the paint layer(s) can be easily applied.

Even saying that, the first and only thing which is the most important in preparing your plastic model’s surface by properly cleaning it to become feasible for a spray paint job.

Also, as you already know the importance of a primer. Don’t settle with any primer you can find. Find a good primer because as we will also discuss later, it protects the insides of your model from oxidation which is the white or green portions you’re going to see in a very old model.

if you want my recommendation, the best is the Tamiya primer which I find to always work like charm. You can find it here.

What happens if you paint metal without primer?

If you paint metal without any primer, what happens is that the metal in your model will be susceptible to oxidation. Oxidation happens when metals are exposed to air causing white or green deposits. Furthermore, the primer acts as a bridge between the model and the paint which enhances paint quality.

Moisture is the biggest enemy for all types of metals whenever they come in contact with it. It is always suggested to use a primer before continuing any paint job onto any metal surfaces, though it is not considered as a pre-requisite.

There is also a corrosion characteristic of the metals and an additional metal i.e., Zinc is added to them to develop anti-corrosion elements in primary metals.

Since untreated metals are more likely to get oxidized and rusty, a primer will be required to save them from any unexpected event before applying paint layers.

In case you do not use primer, the oxidation process will start and the tentative decay and rust will be evident on the metals afterward.

Additionally, the chemical composition of paint compared to the primer makes it vulnerable to flake off easily if there will be no supporting prime layer underside.

For metal, indeed, painting alone will not serve the permanent coating purpose.

There is also a greater chance that if the paint will be applied directly onto the metal, it will unwrap very soon.

Therefore, a primer is used to prevent this from happening.

A primer is somewhat similar to paint expect it is intended to fill in the minuscule gaps available on the material’s surface and also stick to it steadfastly.

Then applying paint over primers will adhere much better due to its high-binding characteristic with the primer.

It could also be possible that any metal might not require a primer before paint job as in the case of stainless steel which already holds the anti-oxidation properties.

There are other metals that don’t oxidize i.e., Tin.

It is widely used for metal coatings as an oxidation repellant or evasive material.

However, in the case of aluminum metal, the surfaces do not grip paint well in the absence of primer.

The aluminum metal also gets oxidized if it is not sealed accurately with primer.

I’ve talked about oxidation and how you can remove these deposits in a separate article. You’re going to find them here: Can you wet a diecast model?

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So, here are the things I love when taking care of my Diecast Models.

Cleaning the Models

The first we are going to talk about is cleaning the models.

Removing Dust

  1. Air Brush – For me, this is the best since it not just removes dust but you can use it in painting/clear coating.
  2. Air Duster – This is a good alternative to Airbrush
  3. Normal Brush – If you are short on budget, you can use a normal brush. However, make sure that the brush has soft bristles because there are some hard brushes than can cause scratches. That’s why I recommended a good brush that can do the job properly.

Cleaning and Shining Hacks

Well, here are some of my cleaning hacks for removing scratches, oxidation, and so much more.

  1. Removing Decal Adhesive – Use Goo Gone on those hard-to-remove decal adhesives. It works fast and works like charm!
  2. Waxing and Polishing – Here is something a lot of people don’t know. Waxing protects the clear coat and paint while polishing shines the model. Instead of buying it separately, use a 2 in 1 to save money. Get this instead.
  3. Beginner Wax – The wax I recommended earlier is good and provides the best results based on my experience. But a beginner might have a problem especially if they’re not good at applying wax. Solid wax reaching hard to reach surface can be hard to remove. You have two choices here. One is to use a qtips to reach those surfaces, another is to use a liquid wax I recommended.
  4. Cleaning Wheels, Rubber, Plastic – Do not forget that rubber and plastic surface are quite different, especially in the cleaning process. Just wiping it down won’t do the job. That’s why I use Meguiar’s Vinyl and Rubber Cleaner and Conditioner. Works like charm!
  5. Make the Wheels Shine! – Making our models look good won’t be complete without tiny details such as shiny wheels! Do not forget this because however small this is, the difference can be as big as night and day.
  6. Remove Scratches Easily – Tiny scratches are not the end for your model. Here is a simple trick I’ve been using to make my models look scratch-free even without repainting. Use T-Cut.

Painting the Models

Painting Tools

Make sure when you paint models, have these ready.

  1. Tape – A tape is important if you are painting a straight line. Furthermore, it will prevent your paint to scatter on other parts. I recommend Tamiya Tape since it is really made for models. Furthermore, they stick really well preventing paint splatters.
  2. Brush (Beginner) – Find a good set of brushes to paint your models. Of course, you can opt for an airbrush but it’s quite expensive.
  3. Airbrush (Intermediate/Expert) – This will yield a significantly better result than an ordinary brush because you can easily spray the paint evenly. I recommend this if you know what you’re doing.
  4. Stand(Optional) – Stands are good because it can be hard to manually hold the models while painting. It is optional but in my opinion, the price is well worth it for the comfort it gives.
  5. Drop Cloths – Drop Cloths will protect your surroundings from the paint.
  6. Primer – The most common beginner mistake I see is painting models without any Primer. A primer will prevent imperfections such as bubbles or paint not sticking to your models. It is a small price to pay for quality results.
  7. Clear Coat – A clear coat will protect the paint of your models. This will make the paint last longer. Also, it is the one responsible for making your models shine.


Of course, you can’t do painting properly without paint. So here are the ones I recommend.

  1. Acrylic PaintGood for beginners because it dries quickly. However, it doesn’t produce results as good as enamel paint.
  2. Enamel PaintProvides a good quality finish and longer-lasting paint. However, it takes longer to dry and requires expertise to use.

Model Maintenance

Model Storage

  1. Simple Wood Cabinet – While it doesn’t let you display your models, wooden cabinets are good storage for these models. For one, they are not heat conductors which means that the temperature inside will remain constant and remain cool. Furthermore, they prevent light from reaching the models which can cause oxidation.
  2. Clear Cabinet with Lock – If you want to display your models, then I recommend this. It closes so dust won’t easily get to your models. I also recommend you don’t put more than 1 model in each compartment since metals are good conductors of heat.

Model Photography

So you want to show off your models to others? Well, I got you covered.

Here is my beginner-friendly model photography tutorial that teaches everything from taking pictures to the editing process.

You will also see me doing hands-on photography in that tutorial.

Here is the link: How to Take Pictures of a Diecast Model or Model Kit | Helpful Illustrated and Video Guide

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