Waterslide Decal Application

Many of us at some time have had that moment when we’ve completed the model we’ve been working on and been let down by the decals supplied, often this has been the backing carrier film showing (silvering), or the decals not settling down correctly on the model. Today’s decals are on the whole good quality and in this short article we’ll look at how to get the best from them.

Decal 'silvering' over matt paint

The example here is a standard rib sided shipping container in 4mm scale, and shows how to a set of decals can be applied to get them sitting into the contours, and minimise the carrier films appearance. Silvering occurs when there is air trapped underneath the carrier film. It is particularly noticeable on matt paint finishes, the paint has a ‘rough’ texture and allows air and water to be trapped easier under the film. (See the picture of the 08 bonnet). When I apply decals I use a gloss finish, if I need to get either a satin or matt finish I overcoat the varnish or lacquer with a matt finish.

To start the tools I use are:
Sharp knife and metal ruler (decal cutting)
Sharp scissors (decal cutting)
Good quality paint brush (around OO size is good)
Mineral water (decal realese)
Micro sol (decal softening solvent)
Micro set (decal setting solution)
Varnish or lacquer as required

It is important to have a good smooth finish on the model to work from. You may find some say that you can apply a waterslide decal on to a matt finish with no film showing. I cannot recall seeing this in many years of modelling and the following technique will get you excellent results every time.

Start with a gloss finish, the containers here have been sprayed with gloss red paint over a red oxide primer and left to harden for a couple of hours. Make sure the area you’ll apply the decals is clean from grease or dust, and then give a thin wash of decal softener. If the area has a compound curve or ridges like this container I will use the solvent. This allows the decal to deform and stretch around and over irregular shapes.

High Gloss Finish

I cut the decal close to the edge of the carrier film, or the logo/writing of the subject. Some sheets like Modelmasters or Cambridge Custom transfers are printed on a whole carrier sheet film, in which case I cut to about 1-2mm form the decal edge. The decal is then immersed in the mineral water for about 20-30 seconds. I use cheap supermarket mineral water as this gives good consistent results, tap water is arguably just as good though. Once the decal starts to move transfer it to the model and apply it as close to the final position as possible. If you leave it too long the decal will pull on the backing sheet and can tear or distort.
With a large decal as shown, I get one part of the decal in its final resting place first and then work to the farthest point. The next part is to place a wash of the softener or solvent over the face of the decal. If the surface is irregular, such as these container ribs the Micro Sol is better to use. If the surface is flat like a van or mineral wagon side I’ll use Micro Set. On this example the Micro Sol will be the better product to use. You will note the surface start to become wrinkled, this is ok as when the decal dries they will shrink and disappear. After five minutes or so the decal will sag slightly as it draws into the surface. At this point I use another solvent wash and use the brush to gently press the decal into the surface. You may see some air pockets forming under the decal, these show in a way you’ll readily recognise, ‘silvering’. I use the brush and gently push the air to the edge of the decal. If you get some that won’t respond its ok to leave them until the decal is completely dry. When it is dry pop the air pocket with a sharp point and then wash over the area with the solvent, this will then get under the decal and help it shrink and draw down onto the surface of the model.

I’ve also attached a shot of where I’ve left a decal with softener, but not initially worked it into the ribs. You can see where the decal has split, however it should be noted that this is not a fault of the decal or the solvents, just a faulty application of both. You can see the comparison shot with the correct method, the decals have formed over the ribs and the decal film has all but disappeared. It’s particularly noticeable on the image showing both the container and the 08 body in the set of the decal and the lack of silvering.

Once happy with the final set, I leave them to dry in the ambient room temperature, and then finish them with either a gloss, satin or matt varnish.