Q and A Guide
Q: What painting tips are you talking about?
A: I have received so many questions about how I paint models;
I think it would be a good place for me to just explain some basic techniques I learned.
These examples assume that you are using an airbrush for painting, but I believe that the guide will work well
for those who use the spray cans to paint as well.
I will also assume that the readers already know how to operate the airbrush set and know the basic concept (single action vs double action, internal/external mix, and so on).
Q: I never get a glossy paint coat even though I am using a gloss paint.
A: Most likely this happens when the airbrush air pressure is too strong, the paint is starting to dry before it
reaches the surface from the airbrush. A rule of thumb is that "a wet coat is a glossy coat". You can either dilute your paint mixture with
more thinner, or reduce the air pressure.
On the other hand, if your air pressure is too low or the airbrush is shooting too little of the paint, this can also lead to non-glossy finishes. In addition, check your room humidity level and ensure that the air is not too dry. In this case, the paint mixture might require more thinner. I use acrylic paints and I just add several drops of water to delay the drying time. Lastly, always test the paint mixture first before painting the actual kit. ^_^
Q: My paint coat runs / my paint coat gets wrinkles / my paint coat has orange peels. What's wrong?
A: First, I would check the paint to make sure that it has the right mixture level. If the paint is too thin, it will cause the paint to run. When you try
to apply an entire coat at once, the surface often ends up with a heavy coat and it can cause a paint run.
On the other hand, if the paint mixture is too thick, the airbrush will "spit" causing all kinds of ugly result. When the paint mixture is improperly thinned, obviously many things can go wrong. A "text book formula" tells that the paint mixture should have a consistency of milk. I think it really depends on the airbrush and its setting. Please experiment with your airbrush set and learn the proper mixture level for your brush.
Q: What do I need to know about airbrushing?
A: Several elements affect the airbrushing. The key elements I can think of are the air pressure, paint/air volume, paint mixture thickness, airbrushing distance, and the humidity level of the painting room. Once someone plays around with an airbrush for a little bit, it will become easy to understand how these elements affect airbrushing.
Unfortunately, I personally think there is no formula which makes everything to work perfect; at least I haven't learned this yet... In another words, I might have a formula for preparing a perfect paint mixture, but if I am airbrushing with a wrong air pressure, my paint job won't come out right. At the same time, it is also possible to have a wrong paint mixture (say it is too thin), but I can still spray without a problem by adjusting my air pressure to make up for the wrong mixture. Even if I had a perfect formula for the paint mixture and the air pressure, he humidity level can throw everything off...
My point is that everything varies and it just makes sense to practice airbrushing and develop an individual technique. The airbrushing concept is something we can all study, please look at the following pictures to understand how one of the key elements play an important role in airbrushing. We will look at the airbrushing distance:
The distance is too far and the paint dries before hits the surface
The only reason where you need to spray from this far away is when the air compressor is delivering a strong pressure and you are trying to "dust" (or weathering) the general area of your model for added realism.
The distance is too close and the paint runs at the surface
When airbrushing too close to the surface of a model (or spraying too much paint), it will likely cause a paint to either run or wrinkle. This is considered a wet coat (wet coat = glossy), but the coat is way too heavy and the surface might cause bumps and spills. If the bumps and spills are minor, you might be able to polish them out.
The distance is good and the paint coats nicely at the surface
A perfect coat! A good distance and the right volume of the paint/air provides a uniform spray. The key is to find a point where the coat is heavy enough to provide a wet look, yet thin enough to prevent the paint run.
Q: My airbrush tip gets paint deposit and blocks the air/paint flow causing it to spit chunks of paint. Whst do I do?
A: The paint is getting dried at the tip and it is collecting paints as airbrush shoots paint. Just clean the tip often with a paper towel as you paint. You can add "water" (assuming you are using acrylics) to your paint mixture to prevent fast drying time to minimize this.
Q: My paint job went okay, but I have some bumps and wrinkles. Is there anything I can do to improve my painted surface?
A: If the surface has very big bumps or wrinkles (even an ugly scar), it might be a good (yet painful) idea to repeat the painting process again. You can sand and/or strip off the existing
paint and re-do the paint work. I go through the repeating process so often, now I just expect my first painting attempt to have flaws. ^_^
If the paint job came out okay with minor flaws, of course, we can always improve on that. The best way I found is to polish these flaws out with polishing cloths. I recommend to use various polishing cloths to do the job, but you can also do this by using similar high grade sand paper.
The polishing cloth has a soft padded backing and it allows you to sand and polish gently. Otherwise, it is just same as the regular sand paper. If you are looking for polishing cloths, the LMG polishing kit (micro-mesh) might be your answer. It has everything you need to do the task; it comes with various polishing cloths, polishing compound, swirl remover, and a cotton towel.
The polishing process is a time consuming work and you should not hurry yourself while performing it. This process can be used to bringing out a deep shine as well as repairing minor paint mistakes. The process is to start out with a normal grade polishing cloth (use a wooden block or similar to provide a flat polishing surface) and switch to a higher grade polishing cloth as you polish your way up.
Please refer the picture below to see how the polishing process works. I recommend that you do this wet to minimize scarring. Finally, be sure not to use any polishing compound/wax if you are going to apply decal or clear coat later.
Taking care of the painted surface
Q: My paint job is never perfect. It contains small unwanted particles. What gives?
A: Wow, Simple! Your airbrushing environment needs some cleaning. ^_^ It is common to have dust floating around the air though. Several things you can do to provide a clean source of air:
1. Having a spraying booth is ideal, at least you should have a fan absorbing the overspray particles. Some modelers also dry their models upside down to protect the painted surface from overspray particles. Thus dry your paint at a clean/safe location.
2. Install a filter around the compressor air intake. This ensures a clean air source.
3. It is inevitable not to have some dust/lint getting on top of the painted surface. Using the polishing technique (lightly sanding them), you can also remove them after the paint has dried.
Dust Particles!
Q: Can you let me know some masking techniques? How do you mask so it has a clean line?
A: I use Tamiya's masking tape to do most of my masking work. They go on smooth and come off easily without lifting paints. A clean masking line can be achieved if the masking coverage is covered fully by the masking tape. I use a tooth-pick to apply the edge of masking tape to ensure the proper coverage. Using a tooth-pick end, I rub it along the masking tape edge. This will help to prevent any paint spills.
Q: My masking tape ruined my painted surface! When I lifted the tape, I saw that the surface was damaged
even with the low tac tape. Why?
A: This happens often when acrylic paints are used. Acrylic paints dry soft. Lacquer paints dry hardest
and the enamel paints are in the middle of them. Even you dry the surface several days, you can leave a finger print
mark on the acrylic painted surface. Be sure to dry the surface completely. If in doubt, dry the suface for at least a week
before masking the surface. If you can't wait that long, then you will have to use lacquer based paints...
When taking the tape off, pull it slowly 120" degrees up from the point where the tape is coming off. By the way, for acrylic paints, I usually take the masking tape off right before the paint dry. As the paint dries soft, it is very likely that masking tape will pull drying paints! Thus, I lift the tape before the paint starts to dry...
Q: I was told not to airbrush at once. Instead I need to spray in multiple coats to achieve a good shine. Would that make the coat to be thick and hide surface detail?
A: Maybe so. Thus it is important to apply right amount of paint. All paints shrinks as they dry. Some more than the other, but they all shrink; the paint can go bit thicker
as they are being applied. Usually, I apply in three coats. First is to cover general area by giving a very light coat followed by anothre light coat to give bit of paint volume.
It is not necessary to have smooth/glossy surface at this time. Before the second coat dries fully, I add more thinner to my paint and I give a final heavy coat. This allows paint to bond
and create an even layer, thus producing a glossy surface. This method is especially effective when applying clearcoat over decals. The first coat is light enough, it won't damage the
decals, but it will protect them by covering them.
Q: Do you know any tricks to paint multiple colors?
A: Obviously I paint the light color first and then move onto the darker color.
Most of the multiple color painting involves masking work. For hard edges, I use Tamiya masking tape to
cover the base color and apply another color.
To prevent a paint bleeding, the masking job must be done correctly. I roll the tip of a wooden tooth pick to
flatten the edge of the masking tape to ensure there is no gap between the masking tape and the surface.
Another way to prevent paint bleeding is to paint clearcoat prior to the second color. When I finish with masking task, I spay a light coat of clear which seals the gap between the masking tape edge and the surface. Then I apply the second color coat soon after as the clear dries. This is bit complicated step, but useful for big scale models where the masking job needs to covere bigger area.
For soft edges effect, I also use Tamiya masking tape, but I fold about 1/8" inch on one edge and flip it back. This covers the sticky surface and it will not stick to the surface. This technique is useful to create a fading effect between two colors. By having a little gap between the surface and the edge of the masking tape , small amount of spray paint can get in indirectly, creating the soft edge.
Painting multiple color
Another trick to ensure that there is no paint bleeding between two colors is to apply clearcoat between the masking job. Spray "paint1" and then mask the surface. Then spray "clear" which will act as a sealer between the colors. Then spray "paint2". Once the masking tape is removed, you will see "paint1" and "paint2" nicely painted without any color bleed.
Q: Can you tell me your technique on painting?
A: Most of the time, I start the painting process by priming the surface
just because it adds the depth to the paint job and helps me to detect any surface flaws prior to the
base coat. For priming, sometimes I use the Tamiya's lacquer based spray can especially for metal/resin kits.
However, I try to stay away from these spray paints because they are very toxic, and
I just hate their fumes. Model Master's acrylic primer works very well for me too.
I know this has been covered in the previous Q&A, but I will explain this in detail here. I usually paint a given model in three application. I give two light coats and then one heavy coat. Based on acrylic paints, I give each coat about 30 minutes to 60 minutes apart. The first light coat is mixed with the acrylic thinner (I use Tamiya) in roughly 5:1 ratio. I try to cover all the surface, but the coat is very light and it may not bring out the base coat color yet. Don't worry if the painted surface is rough. I would let this dry and wet sand the surface if necessary. Then I give another light coat. This time, I give bit more coverage and try to see if the base color is coming out. At this point, I should not see the primer and I concentrate deep corners and edges where the paint usually do not cover well. Again, I would let this dry and wet sand if necessary.
Finally, I mixed the paint and thinner in 5:4 ratio and give a heavy coat. The trick is not to over run the paint, and yet to create the wet surface. A wet surface means a glossy surface. This is how I try to bring out a decent shine. BTW, if anyone is wondering why I give two light coat, these light coats provide biting surface for the final heavy coat preventing the paint run and also adds the depth to the paint.
Q: I am a beginner looking for an airbrush kit. What do you recommend?
A: How about Aztek P4xx series? It's a dual action brush. It means you can control the amount of
the air flow and the amount of paint flow. The dual action brush is harder to learn, but you can always
use it as if it was a single action brush if it gets too complicated.
You can find additional/replacement parts from your local hobby shops, easy to clean, and easy to maintain.
I would also recommend Iwata brands, but they are more expensive.
Generally, you can't really go wrong with airbrushes because I think the market offers all good products. There is no junk out there. However, each brush behaves differently and the learning curve isn't as easy as using spray cans. Airbrushing requires practice and experience counts. If you decided to buy one, you will probably need to stick with it for a long time till you get hang of it. You will also need a compressor, I'd recommend a quiet one if you plan to paint at night. They are loud! Expect to spend around $70 to 120 for an average airbrush, and $120 to $230 for a compressor... If you can find cheaper, then it is already a plus. Some modelers use an air tank from hardware store (very cheap) instead of the compressor, but I don't have any experience with it to comment on it...
Q: Why can't I hand brush parts? Why airbrush (spray)?
A: For small parts, I hand brush. The main reason I use airbrush is to hide the brush strokes painting
large surfaces and to produce smooth painted surfaces. For building military subjects, it is also a different story.
If you can get away hand brushing the surface without brush strokes, that is great.
However, even painting small parts, you can leave brunsh marks. I would dillute the paint with a thinner
case to minimize the marks.
Q: I am using lacquer based paints and seldom I get this kind of chemical reaction. What gives?
Paint Bubbles?
A: 1) Your surface is not clean causing the paint to react. In this case, make sure to wash the surface with clean soap water throughly.
2) If you are using a spray can, your paint is unevenly mixed with the pressure gas inside the can and when it tries to escape the painted surface, it causes bubble. To minimize this, after shaking the spray paint can, let the mixture settle down again (leave it for 5 to 10 minutes). And make sure not to over-spray as it can also worsen the situation.
