|
|
A Word About Decaling ...
by Vince Tassone
December, 2017
BACKGROUND
Allot has been written on how to apply decals and although most articles explain well how to use water
transfers some additional comments are given here without having to comb through the vast literature.
What Are Water-Slide Decals?
Water slide decals or transfers consist of several layers. There is a sheet of backing paper to
which everything is attached. On top of the paper is a layer of water soluable glue. The actual
markings are printed on the glue film and on top of that is the carrier film.
When placed in water for a few seconds the glue will dissolve allowing the decal to slide off the backing
paper and on to the model. Although the glue is dissolved at this point there should still be
sufficient adhesive remaining to stick to the model.
When using high-quality decals (e.g., Cartograf, Microscale) do not trim the thin clear film around the item you are
applying. This clear film is the buffer zone that allows the decal to disappear. Sometimes when using old
decals or kit supplied decals you may need to trim the clear part since the decals may be
irregular or flimsy. It is not recommded to trim the clear film from Stormo Decals.
Two-Part System:
There are two basic decaling solutions and most end in set or sol.
Testors Decal Setting Solution (vinegar based), Mr. Mark Setter, Micro Set (Microscale), etc., are wetting solutions that
allow you to move decals over a surface without carrying air bubbles (which cause silvering) trapped between them.
Always use a clean soft brush to push decals from one position to another, and avoid unnecessary repositioning. This
will weaken the decal glue.
Testors Decal Solvent Solution, Micro Sol (Microscale), Mr. Mark Softer etc., are solvent solutions that soften
decals and allow them to conform to raised and recessed panel lines. The solvent basically dissolves the decal
into its paint pigments so that the final result looks painted on. We recommend the use of
Mr. Mark Softer.
One Part System:
Solvaset (alcohol based) is a solvent without a recommended wetting solution. Solvaset is a strong solvent that
works well on thicker decals. Solvaset can be diluted with water for use on delicate decals.
INSTRUCTIONS FOR APPLYING DECALS
Carefully follow the instructions provided in the decal package. Most of the time high-quality decals
do not need setting solutions, although it is recommended. However, there are times when a little help is
needed.
Decals will adhere better to a glossy surface than on a matt one. After you have painted your model, apply a coat
of Gloss thinned down 20%-25% and allow to dry. It is important to have a gloss or semi-gloss surface to
apply the decals. Matt/flat paints leave a surface that is microscopically rough. If a decal is applied
to such a surface then it will only make contact with the high points on the surface of the paint. When
dry there will be thousands of microscopic air pockets under the decal which will appear as ‘silvering’.
Some modellers only varnish those parts of the model where decals are to be placed, but there is the risk
of producing a ridge at the edge of the varnish.
Cut out each subject carefully. Do not trim the excess clear
film from around the image, since this allows the decal film to disappear when dry. Dip the decal into clean warm
water for 10 seconds. Allow water to soften the decal adhesive for approximately one minute or until the decal slides
easily on the backing paper. Alternatively dip the decal into clean warm water for about 40s or until some some
movement is observed. Do not force the decal to slide before the adhesive is completely dissolved, or the decal film
may tear. Remove excess water from the decal by running it against newspaper.
It is good practice to apply a setting solution to the surface where you place your decal. Carefully slide the decal
onto the wet area and position it in the correct place and wait a few minutes before touching it again. Remove
excess setting solution using the corner of tissue paper through capillary action.
Some decals are printed on a paper called Deca-Fix, leave a white milky residue. This is normal, but the residue
must not be allowed to dry on your model, or you will have a never drying spotty finish on your model when you
apply your final coat
When the surface of the decal is almost dry, apply a solvent solution (e.g., Mr. Mark Softer) on the decal, making
sure the whole decal is wet. Apply again in an hour or as needed until the clear carrier disappears and any
bubbles are removed. Successive light applications of Mr. Mark Softer will eventually remove any bubbles.
Once the solvent has been applied, do not touch the decal afterwards. Let dry overnight. If you find air bubbles or silvering,
poke a small hole through the decal with a pin or the point of a sharp knife at the affected area. Apply solvent over the
bubble or silvered area. If a decal appears to wrinkle, apply additional solvent and let sit overnight, the wrinkles will
disappear. If a wrinkle persists, apply additional solvent until the wrinkle is removed.
The next morning your model should be ready for the next step, which is to wash your model with warm water and a
mild detergent in order to remove the decal glue residue. If this residue is not washed off it can cause fish-eyes in the
next clear coat. Do not scrub the model. Rinse it well and let dry.
A light coat of Gloss will seal the decals, preventing them from lifting or yellowing. Weather the model. Next apply a
gloss, semi-gloss, or flat final finish and apply several light coats of the final clear finish.
In My Own Experiences:
I only use Mr. Mark Softer both as a setting solution and as a solvent. As I mentioned above be sure to gloss the painted surface
and remove as much water as possible before applying a decal. Then apply a liberal amount of Mr. Mark Softer
on the surface and then apply the decal over Mr. Mark Softer. After waiting a short time, apply Mr. Mark Softer
over the decal as a solvent and let sit for an hour. The idea here is that Mr. Mark Softer, its composition is polar and that
it will bond to the decal in a single continuous layer without trapping air bubbles. Also Mr. Mark Softer is a light
solvent, so using it as setting solution has little to no effect on the decal. The result in all cases that
I've used it this way, is a painted on look. Finally do one decal at a time.
Ref. [1] AeroMaster Decals, 1996
|
|
|
