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With varying degrees of success, probably the first tried is brushing. Brush selection is very important. Even in 6" wall brushes, cheap ones will never produce a level coat with the best of paints. The expression, "It looks like it was painted with a stick.", echos true here. Stiff bristles are nothing more than a bunch of miniature sticks tied together by the brush ferrule. Simply, a brush's functions are to pick up, carry and smoothly flow paint onto a surface through a quasi capillary action. Paint is dragged from the tips in fine ridges or brush marks, which level by merging, while still in a fluid state. To keep tips loaded paint must flow down among hairs freely throughout the stroke. Fine pigments and vehicles require fine, closely spaced hairs to perform properly. Flexibility is very important to ensure that the greatest number of tips contact surface. Red sable, sable and some camel hair bristles have these properties, while stiffer ox hair do not. Some synthetics claim to possess them, but try one before investing in quantity. Brush size and shape are very important. A 00000 spotter's brush may be ideal for painting eye brows on figures, but is totally useless for painting the broad side of a barn. Round, pointed tips may hold large volumes of paint for repeated small dabs, but they can not place enough tips on surface evenly to spread an even, broad swath. They are good for edging or narrow striping, if your an artiste. For large surfaces, flat brushes provide the greatest tip contact number. Within limits, wider is usually better to reduce number of strokes and possibility of holidays between them. Fan brushes may yield very wide swathes, but more often, do not carry enough paint for a reasonably long stroke. Particularly on large surfaces and with faster drying paint, stroke in one direction only. Stoking back and forth may cause tips to stick on partially dried areas, producing stripes or mottled effects. A light touch will ensure that only the tips, and not the sides, of bristles contact surface for much smoother spread. In many cases brushes, with poor painting qualities, can be used to produce very effective weathering techniques. Paint selection can be quite confusing, even without hype and apparent economy influence. In spite of often unheeded, offered advice, a major portion of complaints concerned paints. For brushing, prime requisites are compatibility , opaqueness, flowing, leveling and adhering abilities. Some solvent paints and lacquers react with and attack substrates, including paints and styrene, causing blemished finishes. Even annealed styrene may craze and crack with wet coating. If cured for over two weeks, Floquil itself is not effected by additional coats of Diosol (xylene). Be certain of compatibility. More apparent when applying a light color, like white, over a dark surface, like black, opaqueness or hiding ability is very important. Lack of coverage is caused by holes amidst adjacent pigments, which permit the background color to show through. Used by lower quality paints, one solution is to apply a thicker coat or additional coats to overlap holes. To provide a thinner coat that does not hide detail, a better solution is to grind pigments finer to reduce hole sizes. To paraphrase Floquil, miniature paints require miniature pigments. Thinning paints, for spraying and other reasons, spreads pigment particles apart to agrevate the condition. This may be great for washes and weathering, but usually not the base coat. Flow characteristics are more apparent before and during strokes. If paint is too thin, it may not be picked up by bristles or drip during transport. At the surface it may spread or creep into unwanted areas, even under masking. On the other hand, if too thick it may not flow down bristles to provide an even swath and may cause build up around detail and masking edges. These are common with cheaper, heavier vehicle paints. Leveling occurs immediately after surface contact by merging ridges and separate strokes, through surface tension. To accomplish this before setting, sufficient fluidity must be obtained and maintained. Faster drying paints require faster leveling. Adhesion almost speaks for itself. If it does not stick well, it is useless. But too often, the ability is not apparent until a much later date, when coating wears off at sharp edges, or worse, peels or flakes off. Occasionally this may be due to lack of proper preparation, but it is not uncommon with some paints, particularly on metals or other smooth surfaces. Lacks in most of these factors are much more apparent in gloss coats with mirroring reflection; where even the slightest imperfections angle reflected light, quite differently and visibly from that of the main surface. With their minute rocky surfaces, flat and matte finishes scatter and diffuse reflected light, reducing visibility of flaws. But a poor paint job still may be quite evident. The secret behind a good paint lies in how well the desirable factors are combined. Too often, in hobby paints, one or more is deficient. Though usually safe on plastics, enamels generally are lacking. Mostly glossy, at the bottom of these, are the ubiquitous Testers Pla, followed not too closely by Pactra 'Namel. By experienced painters, both are often referred to as "chewing gum" or "kiddy paint". From false economy, they are often chosen for lower price for a smaller bottle. But since smaller bottles are more expensive than their contents, ounce per ounce these paints are more expensive than much better quality paints. Particularly with Pla, pure metallic colors tend to "tarnish". Despite their water based vehicle, acrylics are probably the best brushing paints for general use. With the exception of adhesion to metals, they possess good qualities in all factors to a varying degree. With fine pigments ground by the same method as Floquil, a very wide selection of flat railroad and military colors, possessing excellent brushing characteristics, Poly S is most likely the best choice. In later years metallics and glosses have extended the line. Although mostly military colors, Tamaya is a good choice for odd colors. Pactra's acrylics include colors useful for structures and scenery. Since many are earth colored camouflage hues and acrylics dry brush well, military paints are a good source for weathering. The use of solvent based paints should be avoided on most plastics, especially styrene. However they usually have better adhesion qualities on metals and usually produce thinner coats. Brass, for one, offers a very difficult bonding surface. When baked at 300 ° F., at some undetermined time, Scalecoat forms an excellent bond through chemical reaction. Baking any paint at lower temperatures will accelerate drying, harden finish and improve bonding, but care must be exercised to avoid softening plastics and paints. Especially with glossy and slower drying finishes, it is very important to eliminate any possibility of dust or other foreign contamination until thoroughly set. BACK TO PAINTING AND COATING BACK TO METHODS INDEX |
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