Working with Water Slide Decals

This is a tutorial for applying water slide decals. I prefer these decals over the dry transfer decals for ease of application. There are a couple of important steps that need to be applied to the parts before applying the decals. The most important step is to apply a gloss clear coat and allowing this to cure prior to applying decals. A gloss clear coat creates a very slick and smooth surface on the parts and this is the perfect environment for the decals to stick. If the surface has not been properly prepared, the decals will not stick very well onto the surface.

As a side note, the decals I use are from In come cases, the decals can be a bit on the delicate side. Meaning the ink for the decals rub off VERY easily. To counter this, simply spray a thin layer of Mr Super Clear over the decals and let that set and cure over night. This gives a protective layer over the decal ink. The down side to doing this is that it makes the decals thicker so after the decals have been applied, you will need to deal with the decal edges.

The decal is placed into water and let the decal soak for about10-30 seconds – this all depends on the age of the decal, the decal paper, etc. There is an adhesive in the decal that the water loosens up, but keeping the decal in the water for too long completely dissolves this adhesive. This in turn makes the decal harder to stick to the surface and may lend towards decal silvering (edges of the decal lifting up off the part).

Next, remove the decal from the water and set it down on your work area or paper towel. The water will soak into the decal backing and after another 30 seconds to a minute, the decal will easily slide around on the decal backing. Simply slide them onto the parts. You can use a toothpick to position the decals while it is still wet. Another technique to positioning the decals is to use a moist q-tip. With the q-tip, the decal can be carefully lifted and repositioned. Once the decal is in the proper position, take a paper towel to soak up the excess water. Then carefully press the paper towel against the decals to rid most of the water. Let this sit and dry for a while before moving on.

Now that the decals have been applied, you may notice that some of the decal edges are noticeable or not conforming well to the curves of the part. To fix this, I use a decal setting solution, Micro Sol setter to set and soften the decals. There are several brands of decal setting solution, and some are stronger than others, so care must be taken in choosing the correct decal softener. Mr Mark Setter and Mark Softer are gsi products that are meant for use over lacquer based products. Microsol is acrylic based products safe to use over acrylic surfaces. The decal setter/softer melts the decals so that it conforms to the shape of the surface. All I do is apply the solution with a brush and let it evaporate on its own.

Here is a video of the process:

In some cases, when the solution is applied to the surface of the decal, you will notice that the decal wrinkles up. Just let this sit and it will evaporate on its own. DO NOT TOUCH the decal. Once it evaporates, the wrinkles will be gone. Then let the setter sit for a full day before proceeding with the next step. Here are pictures of decals wrinkled, then without wrinkles after the decal setting solution has fully evaporated.

Once the decal setting solution has cured for a day, it’s time to get rid of the decal edges that may still be present. For this, the first step is to spray a clear gloss to sandwich the decal. At this point, a decision on if the part will be glossy or flat comes into play. If the part will have a flat finish, the decal work is done and a flat can be sprayed onto the surface and the decal lines will fade away easily. However, if you want a glossy finish, there are a few additional steps that may be necessary for dealing with the decal edges. First, I spray several layers of clear gloss that completely covers and encapsulates the decal on the surface. The gloss is left to cure over night, or for two nights depending on how thick a layer of gloss is sprayed. This usually removes the decal edges.

However, if the decal edges are still visible after the above steps, then I recommend trying the following. Use a high grit sanding pad, and lightly sand along the edges of the decal. The idea is to slowly remove the gloss that is built up around the edges, and only sand the gloss. In the following picture you can see the decal edges fairly clearly.

Imagine a cross section of the decal as it sits on the surface of the part. Below the decal is a layer of gloss, and below that is the paint layer. Now above the decal layer is another layer of gloss. The gloss builds up around the edges as well as the area of the parts that don’t have the decal. So there is a slight leveling difference if looked at on a cross section. To resolve this, a very high grit sanding pad is used to run across the edges of the decal. Since the paint and decal layers are protected, slight sanding will only remove the excess clear gloss layer. The surface will look cloudy after the sanding session.

Here’s a video on that process:

The following pictures shows the fuel tanks sanded. The edges are sanded and the overall luster of the gloss is clearly gone in the picture.

This is fixed with the final layers of clear gloss sprayed over the sanded decals. And with the final clear coats, the decal edge lines should be completely gone. And here are some images after the final clear has been sprayed.

In the above picture, I have several parts that are glossy and two that are flat coated. Decal edges are much easier to hide with a flat coat than with a glossy surface. The sanding process was not used on the flat coated pieces, only the glossy surfaces.