Decal Application 101

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Home :: Tutorials :: Decal Application 101

Tutorial #110

Title
Decal Application 101

Author
2whl

Published
Monday, November 24, 2008

Overview
Decal Solutions
Compound Curves
Clear Coating
Problems

Gaps
Wrong Position
Air Bubbles
Yellowing
Old Decals
Silvering

Overview

Lately it seems as though there have been a number of people asking about decaling. Some people are scared of this aspect of the hobby, but there is no need to be. I find decaling to be enjoyable. I had better find it fun because all I tend to build are race cars. This tutorial is a blending of many techniques from this site and some of my own. So, let's get started.

You will need to gather a number of things together to achieve satisfactory results:

1.A model
2.Decals
3.Kit instructions or similar documentation for decal placement
4.A container of water
5.Scissors
6.Tweezers
7.Brushes
8.Toothpicks
9.Q-Tip
10.Paper towels
11.A hobby knife with a new blade
12.Solvents

Most of these are common sense but there are a couple of things to consider. The container must be large enough to wet your largest decal. The brushes must be brand new. I keep brushes set aside just for decaling. I also keep a brush with each of my solvents. Also, you should file the point of the toothpicks off so they will not injure the decals.

Tutorial Photograph (1.jpg)

Get your decals and documentation (pictures, kit instructions, magazine articles, etc) together and determine where each of the decals will go. Also consider which decals should be applied first.

Make sure the surfaces you will apply the decals on are as smooth and clean as possible. Decal adhesion is enhanced by a smooth surface. If you polished the paint there will be residual polishing compound remaining. Also there could be skin oils present. These kinds of substances will not let the decal adhere properly. Go over the areas you wish to decal and clean them.

Tutorial Photograph (2.jpg)

Check the decal for the clear film immediately surrounding the decal. Most kit decals have a small amount of clear film visible. Some decals will have the whole sheet cleared. In this case, you should cut as close to the decal as possible.

Tutorial Photograph (3.jpg)

Cut out the decal you want to apply.

Tutorial Photograph (4.jpg)

Dip the decal into the water. It will probably curl up, so don't worry.

Tutorial Photograph (5.jpg)

I usually place the wetted decal on a hard surface until it uncurls. Some people will leave the decal in the water. This could be a problem if the decal leaves the backing paper. Also, if the backing paper is washed off of the decal the glue between the two could also be washed off.

Tutorial Photograph (6.jpg)

Wet the area where you want the decal with some water.

Tutorial Photograph (7.jpg)

Once the decal uncurls it is ready. If you touch the decal with your finger now it will probably stick to it.

Tutorial Photograph (8.jpg)

After the decal uncurls it should be free of the backing paper. Slide the decal into position. I usually use a toothpick or Q-Tip to maneuver the decal. Some people will use their fingers. Just be careful because the decal can stick to your finger.

Tutorial Photograph (9.jpg)

Use a Q-Tip to gently push the decal into position. If the decal doesn't want to move use the brush to add a little more water. Use as much water as necessary to get the decal to slide into position. Now is the time to make sure the decal is exactly where you want it to be. Be careful moving the decal around. Most decals are very thin and are easily torn.

Tutorial Photograph (10.jpg)

Once the decal is in position soak up the excess water with a paper towel or napkin. Just soak up the excess water by blotting. Do not push the decal around. Again, most decals are very thin and easily torn.

Tutorial Photograph (11.jpg)

I will usually use a Q-Tip in a rolling motion to push air bubbles and excess water out from under the decal. Start from the middle of the decal and work your way toward the edges.

Tutorial Photograph (12.jpg)

Your decal should now look like this. Let this decal dry for at least 30 minutes before putting any other decals next to it.

Tutorial Photograph (13.jpg)

Decal Solutions

There are two types of solutions used while decaling:

1. Setting solutions such as MicroSet which help decal adhesion sort of like a glue. MicroSet should be used to wet the area of the car on which the decal is going to be placed. Care must be taken because MicroSet will soften the decal slightly making it easier to tear.

2. Solvents such as MicroSol or Solvaset which soften the decals to bend them around curves or into crevices. When using solvents allow the decal solution do its job. Any wrinkles you see will smooth out on their own. Do not touch or try to move the decal since it will be soft and easily deformed or damaged.

Tutorial Photograph (14.jpg)

Solvaset is a very aggressive solvent which will virtually liquefy the decal. After being applied the decal will wrinkle up. You will think you have just destroyed the decal. That is what it is supposed to do. As it dries, it will suck the decal down into every fold and crevice as if the decal has been painted on.

Tutorial Photograph (15.jpg)

If you are not sure about the compatibility between your decals and solutions you should test first on a spare decal. Most decal sheets have the manufacturer's label which could be used and are thus good for testing.

Tutorial Photograph (16.jpg)

When using a setting solution I will usually use it to wet the model.

Tutorial Photograph (17.jpg)

Then I will place the decal and use a Q-Tip to get the decal down as much as possible.

Tutorial Photograph (18.jpg)

Compound Curves

There are a couple of different ways to handle compound curves.

I usually use a solvent solution to soften the decal. After the decal has dried enough so it will not move apply the solvent.

Tutorial Photograph (19.jpg)

Once you have applied the solvent do not touch the decal. The solvent softens the decal considerably and makes it very easy to tear. Let the solvent do its job.

Tutorial Photograph (20.jpg)

Another way to get the decals to conform is a little trick that involves a hot wet towel (paper towel works too). To start with, decal the car and make certain all the decals are in the positions they need to be in. Then allow them to set in place. Once they have set enough that they won't move around get the water running out of the hot tap at a temperature you are just barely comfortable with. Now wet the towel and wring out the excess water. While the towel is hot place it firmly over the decal (do not move it around) and after a few seconds remove the towel The decal should be conforming to the surface. You may need to repeat this step.

Yet another way is to use heat and solvent together. I haven't tried this method so I will just repeat what I have read. Get the decal in position and partially dried. This is the time to brush on solvent and add heat. Use a liberal amount of solvent with a brush. Then use a source of heat to aide in forming the decal. You can use a hair dryer on the lowest heat and air-speed setting. The heat should start to form the decal to the curve, but will dry the solvent faster. Once the solvent is almost gone let the part cool. At this point the decal probably won't be all the way against the surface, especially on a rough surface such as a grill. So repeat until it is.

Tutorial Photograph (21.jpg)

After all the decals have completely dried (I wait until the next day) use a damp cloth or paper towel to remove any residual solvents or glue. When cleaning the decals brush from the center of the decal outward. You want to avoid catching the edge and lifting the decal up.

Tutorial Photograph (22.jpg)

Clear Coating

After all the decals have been placed some people will clear the model to seal the decals. This will give the model a consistent matte or gloss finish. It also smooths the edges between the decal and the paint.

Again, I would test a scrap decal with your clear to make sure it is compatible. Sometimes lacquers like Tamiya and Duplicolor will react with the decal. In this case you might want to use a less potent clear coat such as Mr. Hobby clear coat, Tamiya acrylic clear coat, or possibly Future. Apply the clear coats just as you would any other paint layer. Start with a mist coat, then a slightly heavier coat, followed by the wet coat. Of course you should wait at least twenty minutes between each coat. If the decal is going to react to the clear at all the mist coat will do very minimal damage as compared to a wet coat which can seep under and lift the decal. Also, the mist coat will seal the decal from the succeeding wet coats.

I usually do not clear my race cars. The reason is because modern race cars are not cleared. They will have a smooth glossy finish, but not a show car quality paint job. Then the graphics and decals are applied as mylar sheets. So it is actually more realistic to not clear.

Problems

Gaps

Sometimes you will have to place a decal over a gap. Between two body panels, louvers, etc. You need to let the decal dry completely so it will not move as you work with it. Now carefully slice the decal at the gap with a new X-Acto blade.

In the picture you will see I am about to slice the decal on an angle to allow it to curl around the blower notch. Then paint on some solvent and allow it to do its thing. You should see the decal start to snuggle down.

Tutorial Photograph (23.jpg)

In this picture solvent has been applied to the opening and also to the top of the windshield. You can see the decal conform itself to the openings. Sometimes it might not go all the way the first time. If not, allow the decal to dry completely. Now slice the decal again so that it will conform to the gap. Apply more solution and once again let it work.

Tutorial Photograph (24.jpg)

Wrong Position

Sometimes, after the decal has dried, you will notice it is in the wrong position or something is under it. You have to remove the decal without destroying it. Since the decal is being held down by a glue you need to get this glue wet so that it will release the decal. Use a brush and plenty of water. Start at a corner and use the brush to work the water under the decal. As the glue gets wet the decal will slowly release and you will be able to get water further under the decal. This is a very slow process and you want to be careful because the decal can be easily torn. Keep going until the decal is free. Reposition the decal (remove any foreign objects first) and use a setting solution to re-glue the decal. I have heard of people using Scotch Tape to remove the decal. While I have not tried this you would almost certainly destroy the decal trying to get it off. It might be great for removal, but not for re-positioning.

Air Bubbles

No matter how well you lay your decals down occasionally you will get an air bubble. Normally you would work the air out while the decal is still wet. If the decal has dried poke the bubble in the center with the tip of an X-Acto knife. Now apply some solvent to the bubble and carefully work the bubble out.

Yellowing

Old decals will occasionally yellow with age. The trick here is to tape the decal to a window facing the sun and let the UV rays bleach the decal. Check the decal often until you are satisfied with its color.

Old Decals

With old decals sometimes the glue becomes milky or yellow. In this case you will want to get all the glue off of the decal. Throw the decal into your water pond and let it stay there until it floats off of the backing. Let it stay in the water long enough to dissolve the old glue. Since there is now no glue on the decal you will have to use a setting solution to adhere the decal to your model.

Silvering

Silvering happens when very tiny bubbles of air get trapped underneath the decal. This is because the surface is too rough (matte). To prevent this from happening you must make sure the surface is smooth. If the area needs to be matte you can decal first and then use a matte clear to achieve the desired effect. That is the technique I generally use on tires. If the decal has already been applied and silvering occurs you have two options. You can remove the decal, smooth the surface, and then re-apply. Or you can use Solvaset to sufficiently soften the decal to get it to conform to the rough surface.

Tutorial #110