Masking liquid or masking fluid is a liquid that can be applied to models. It comes in a bottle with a brush attached to the lid. It is often a light paint, made to cover up the areas of a model where there are unwanted parts underneath. It also has a variety of uses, as listed below.
It can be used to stain the surface of an object, for example, if the wood is stained after its application. Masking fluids are needed to paint a part of an object without painting over the rest. One would paint the thing with tinted liquid, usually translucent. After drying, one can protect the result by painting over it with glue or varnish. This is used in the building of ships and model railways.
Another use for masking fluid is to protect parts of a model, such as windows or painted details on the body of a car during removal or handling during construction and repairs. One can apply this by hand (brush), airbrush, paint spray etc. Cleaning spray is often used to remove the hardened masking fluid afterwards.
Stencils for Painting
Masking fluid can also be used to make stencils. These are similar to the masks which painters use during house decorating but much more refined. Using stencils can speed up painting considerably. Blade-type stencils are often used to paint fine lines and patterns. Another way of using a stencil is to make a masking fluid sandwich, where one uses masking tape and masking fluid in the same operation.
Another use of masking fluid is to achieve a contoured, textured surface. This can be done by applying the liquid with a brush as a series of parallel lines or as dots that build up areas of texture. After drying, this results in a patterned-textured appearance which makes an object look more attractive. This technique of rendering is handy on outer space miniatures.
Masking fluid can also be used to model the effects of mud, swamps and other impacts which involve water or liquids settling in low areas. This can be applied with a paintbrush or airbrush over the base coat. After drying, this creates a ‘water pooling’ effect which should be painted over with other colours to add more realism.
Masking fluid can also paint ropes, especially where the rope has a twisting shape. The masking liquid is applied in lines or spirals along the rope. These are usually painted over with black paint for contrast, so it does not get confused with the surrounding areas, which have been masked off.
Masking Aircraft Camouflage
Masking fluid can be used to paint camouflage patterns on aircraft. The masking liquid is applied as a series of dots or lines and then painted with appropriate colours. This should not be done too heavily since the idea is to only partially obstruct the base coat beneath so it still shows through. This is only necessary for models painted over in different colours.
One can also use masking fluid to protect parts of a model they do not want to get fingerprints on. This might be because the part looks better without them, or the fingerprints interfere with the paint job. One will first wash the hands to remove the oils if used for cooking or gardening. Then one would paint a lighter-than-normal coat of masking fluid over the areas which need protecting and let it dry completely. One can add another layer if necessary. This makes it easier to clean the fingerprints off, but only when the paint is completely dry.
Masking Iron Figures
To make iron figures look more realistic, one can use masking fluid, especially on rust exposed areas where the wire brush has revealed some of the ‘tin’ beneath. Masking fluid is applied in thin coats with a brush, and then the iron figure is painted over with black paint so that the masking liquid rises to the surface. This can be applied in patches or more heavily for a rougher appearance since it is used as shading rather than colouring.
There are many uses for masking fluid, some more valuable than others. It is worth experimenting with it to see what can be done. It is a good idea to keep some on hand since it comes in helpful more often than one might expect.