Components: To paint or to spray, that is the question

[radiozero]

I'm NOT trying to restore the electrical components as original. That is not required. What I need to do is apply a covering to the Parmeko transformer I have and the rectangular TCC metal-enclosed paper capacitors.

Both the transformer and capacitors in fact were a grey in colour. But, I do not intend to use the same colour. I'm not sure about the Parmeko, but I reckon the TCC capacitors were probably sprayed.

I'm supposing that I'll get a decent-enough result if I just paint the components with Humbrol paint. I'm not sure though which is more suitable, acrylic or enamel. Or should I use a spray paint?

Of course, we are talking components, not set enclosures. I think blue might be a nice colour. :c)

Any thought on the matter? Thanks.

[M0FYA Andy]

My opinion, for what it is worth, is that you should always aim to repaint such components in the original colour or one that you know the manufacturer used.
Repainting in a colour the manufacturer didn't use makes the job look amateurish and home-made!
I think spraying tends to give a better result and is easier to do.

Andy

[Michael.N.]

That might depend on who is doing the spraying or brush work. My expertise is with varnish rather than paint but I suspect that it's quite possible to get stellar results with a brush.

[mikelect]

Rollers give an extremely good finish but probably not small enough for chassis work HTH

[Lucien Nunes]

I always spray. If only doing one or two trannies I don't tend to bother with setting up the gun, just use a can. I think it would be acceptable to spray components with a colour that relates to the finished unit if they are visible from outside. OEMs have been known to do this, caps on Leaks being an obvious example. Hidden components, being sprayed for protection or tidying up only, will probably look odd in anything different to their original colours.

Lucien

[radiozero]

The original covering was just plain, no crinkle or anything. If I do paint, should I go with Humbrol acrylic or enamel?

[fidobsa]

If brushing I would use enamel. Get the parts as clean as possible and use long, slow brushstrokes, making sure the paint is well spread out to avoid runs. Two coats should be enough if using Humbrol enamel. I tend to hang parts up to dry in a cupboard or spare wardrobe so they don't get dust settling on the wet paint.

[radiozero]

What is the difference between acrylic and enamel?

Acrylic paints are composed of synthetic resins (usually acrylic or vinyl acrylic) and pigments dispersed in water. Acrylic paints dry by evaporation of the water causing the particles of resin to fuse together forming a continuous coating. Acrylic has excellent adhesion, colour and gloss retention, long-term flexibility, and toughness. They are also easy to apply, clean up in water and safe to use. Most acrylic paints must be protected from freezing and applied at a minimum temperature of 10 degrees C.

Enamel or enamel-based paints are coatings produced by reacting a drying enamel acid with an alcohol. Drying occurs by the evaporation of a solvent; curing of the resin occurs by oxidation. The more enamel there is in the formula, the longer it takes to dry, the better the wetting properties, and the better the elasticity. Enamels can be used as interior or exterior trim paints, machinery enamel, or durable wall finishes. Top quality enamel-based paints also offer excellent adhesion, but there's a trade-off. With the passage of time - and depending on the substrate, weather conditions and the particular paint - enamel-based products can yellow and become brittle. In extreme circumstances enamels can begin to crack in just a few years. Enamel coatings should not be used directly on masonry, galvanized metal or other alkaline surfaces to avoid saponification.

Acrylic vs. Enamel Comparison

Durability - Enamel -Excellent adhesion; better adhesion than acrylic on heavily chalked or powdery surfaces. Ability to stop the bleeding through of most stains. Acrylic - Excellent adhesion to most substrates; better elasticity than enamel, but allows the bleed through of most stains.

Colour Retention - Enamel - Not as good as acrylic; more likely to chalk and fade in sunny exposure. Acrylic - Superior resistance to chalking and fading, especially when exposed to bright sun. Does not yellow like enamel.

Ease of Application - Enamel -More difficult to apply due to greater "drag," and need to keep a wet edge. Needs to be washed up with smelly and unhealthy solvents. Can not be applied with out an undercoat. Usually takes 24 hrs between coats, 8 or so hrs to be touch dry and 3-5 days to be case hardened or fully cured. Acrylic - Goes on smoothly and evenly, with less brush drag.) Much easier to apply and can be re-coated with out the need of an under coat. Can apply more than one coat per 24 Hrs. Only takes 24hrs to be totally case hardened or cured.

Mildew Resistance - Enamel - Vegetable enamel base can provide nutrients for mildew growth; most products contain a fungicide to minimize growth. Acrylic - Less inherent tendency to grow mildew; anti fungicide additives discourage mildew growth, help maintain fresh appearance.

Versatility - Enamel -Can be used on most substrates, but for new concrete, stucco and other masonry, sealer or pre-treatment is required; should not be applied directly to galvanized metal. Enamels main use these days is on trims, windows etc. Acrylic - Can be used on wood, concrete, stucco, brick, galvanized metal, vinyl siding, aluminium siding, etc. (Recommend primers as appropriate))

Odour - Enamel -Noticeably more odour than acrylic.
Acrylic - Very little odour; non-combustible.

Clean-up - Enamel - Requires hydrocarbon solvents. Turps.
Acrylic - Simple water clean-up.

Drying Time - Enamel - Eight to 24 hours normally.
Acrylic - One to six hours, permitting quick re-coating.

Quoted (more-or-less) from a more fuller article at:

http://www.sydneypaintingprofessiona....au/faq.htm#16