BRUSHING UP
Powder-coating has become the popular no-fuss paint work solution, but it' s far more satisfying to apply good old-fashioned enamel paint-by brush. oily boot bob explain show to achieve a finish fit for an Old Master...
Powder coating has become the popular no fuss paintwork solution, but it's far more satisfying to apply good old fashioned enamel paint by brush. Oily Boot Bob explains how to achieve a finish fit for an Old
Master...
Brush painting a motorcycle frame is a whole lot more satisfying than painting a window frame or any other household woodwork. Applying careful, deliberate brush strokes to the sound of classical music I particularly like piano concertos is highly therapeutic and you're adding personal craftsmanship to the aesthetics of your motorcycle. Saving a few bob is a good thing too.
The golden rule for brush painting has always been to buy the best quality brush to produce a good finish, and this advice still stands. Picking loose brush bristles from your freshly applied paint work is soul destroying certainty if you buy cheap brushes. But there 's another consideration . For me, the best brush is no longer the traditional decorating brush made of bristle; they're just too stiff and coarse for applying enamel smoothly onto metalwork. Water colour artists use broad, soft brushes to apply a watery'wash ' asa foundation to landscape paintings, and they're also perfect for our needs. Some are still made from animal hair, but synthetic hairs are more the norm, and probably cheaper.
In a moment of intrigue (anoraknia?), I took a micrometer to one of my favourite Daler rowney water colour brushes .The hair diameter measures 0.002" (two thou) whereas the bristles of the Hamilton brush are unsurprisingly four times thicker. The lighter flex of these brushes allows a more delicate control of the paint and, unlike the bristle counterparts, leave no trace of brush marks in the surface finish. I used a one inch (25mm) brush for almost everything until I recently discovered that a 1Vi''artist 's brush is available, which makes quicker work of larger areas of tinware such as mudguards and tool boxes.
Tekaloid 318 Coach Enamel is well known to those who still enjoy the old fashioned way of applying paint to motorcycles. Smith and Allan are able to mix this to your colour requirements as well as the ever popular regular gloss black. Their own grey primer provides a good foundation, but I prefer a metal oxide primer, particularly Black Friar.it can be effortlessly sanded down to a smooth finish within a couple of hours of application, which unfortunately cannot be said about the gloss enamel top coat. There are plenty of other similar products available , but Itend to stick with what I know .
These durable enamels don't harden
like the cellulose or stove enamel of olden days, but may provide a better resistance to chipping, which can in any case be retouched years after the original application. The downside to this durability is its lengthy full curing time of two weeks or more, before being able to rub down a bad finish. The messy alternative is scraping it all off while it 's still tacky.
Starting at the beginning with surface preparation is a good idea. Bare metal is fine, but not necessary.i've never understood the need to remove all existing paint, sometimes by grit blasting, if a large portion of original factory enamel remains intact. Paint which has clung on tenaciously for several decades will do so for a few more. Simply feather the edges of patchy paintwork to blend it seamlessly to bare metal.
If the frame is cracked it will be as visible through the well hardened old paint as on bare tubing. You can touch up the bare patches with primer, or it may be worthwhile giving the whole subject an all over foundation coat or two, rubbed down. If the origin of your bike is unknown, it's a good idea to test a hidden area of paint for compatibility; I remember that oil based enamels reacted like curdled milk when applied on top of a cellulose finish .
Wet and dry abrasive paper comes in many grades and, as the name implies, can be used wetted with water. Gradesof between 600 and the finer 1Oooare usually enough for my needs, and it works out very cheap if you use the sheets wet so that they can be reused. An hour or two spent in the garden with a bucket of soapy water and some garnet paper on a bright day will produce good results. Rinsing the abrasive paper in water prevents it from becoming clogged with paint particles.
Lightly pock marked areasof metal can be filled with more than one coat of rubbed down primer until you 're happy with a smooth finish, which should be finally cleaned with a lint free, dust free cloth, moistened with solvent I brush cleaner. A quality kitchen cloth can fill this role, but don't be tempted to use one of your old T shirts from the rags box . An invisible forest offluffwill have sprung up in the cured paint when you admire your completed work in sunshine .
Having cleaned your workpiece you should now consider your workplace to apply the top coat(s) for the same reason, preferably away from where you 've been sanding. Yearsof invisible dust finds its way into my paintwork when disturbed by the opening of the big up and over garage door .This isn't critical on primer that will be rubbed down, but is to be avoided during the final enamel work .
Painting in the garden provides the best
light source, particularly when applying black paint, but the necessary calm conditions increase the risk of small flies and insects becoming a feature of your handiwork, as do cat and dog hairs in any location. Moving the portable workbench to the spare bedroom works well for me. I can close the door and leave the parts to dry undisturbed for a day or two.
The technique for brushing paint will vary depending on the viscosity and the drying time of the paint, so experimentation is the only way. I like to load the brush well with Tekaloid, then spread it out over a large area with long slow strokes in the same direction until the paint is of a uniform smooth thickness. Too much paint in one coat will run into dribbles. It's better to apply a second coat on top of a thin but uniform first coat. A sizeable surface can be worked while wet if the tin is freshly opened, but you'll need to work quicker after the lid has been off a few times and the spirit has evaporated as the volume decreases.don't be tempted to return to areas of already drying paint, the brush will drag the tacky finish into horrid ripples which can only be resolved by scraping it all off with an old bank card, wiping clean and starting again.
To prevent air entering the tin, ensure that the lid is replaced in the same position each time by marking it against the rim, then give it a shake to form a seal around the lid. Some people store paint tins upside down for this reason and to force any skin forming at the bottom of the tin. It also gives you a head start to stirring it when turned upright again.
If you're starting out on the frame, practice your technique on areasthat will be hidden from view on the assembled bike, then move onto the more visible areaswhen you've gained confidence. There'snot a lot of point in producing a good finish on hidden parts, where corrosion protection should be the priority. Many (most?) manufacturers had a similar view, probably to reduce labour costs by dipping small items in the paint and hanging them to drip dry.
Large prominent surfaces such as mudguards and toolboxes are best attempted when some confidence and experience have been gained, and a petrol tank may require a giant leap of faith .To paint the centrepiece of your motorcycle in one shot without error would be quite an achievement. A harder drying paint can be corrected as many times as necessary by rubbing down and retouching. In this case,your only limitation is time.
A couple of years ago I painted the petrol tank of a 1938 Royal Enfield Model J which I'd purchased in a cosmetically sad state. Anything better than tidy paintwork on the scruffy octogenarian would have looked out of place, so I was under no pressure. I don't think metallic silver can be brushed uniformly enough, so a Hammerite aerosol replicated the chrome portions of the original colour scheme.
The three panels of the masked tank were then brush painted in maroon , bordered with 3mm adhesive gold pin st riping the weak point of the job which conveniently masked
some uneven line work. This tape works fine in straight lines and sweeping curves, but does not like being forced round tight radii. I keep thinking about buying some of those floppy sign writer's brushes and trying to paint my own gold lines.
Finally,the decals were stuck onto the three tank panels and sealed against petrol attack with a coat of yacht varnish, which spreads nicely to a smooth finish, and the same on the gold lining. It resiststhe nasty combustibles of model aircraft fuel very well, so a bit of spilt Unleaded 97 won't do any harm. If in doubt, dip a test piece in petrol. I use Black Friar and Ronsealbrands, which are not clear as it says on the tin. They have a honey coloured tint, so must be applied sparingly on top of light colours to avoid sepia coloured features. Maybe it's time I strayed further than the hardware shop to buy some kind of truly clear lacquer.
Ageing paint can be thinned to a workable consistency once more by diluting it with Barrettine (brush cleaner) but once diluted it can't be stored, or it will separate and solidify in a few hours, so only mix what you need. The makers will recommend specific solvents which will surely be longer lasting. This separation is handy for saving some more pennies when it's time to clean your brushes. If left for a week to settle in a bottle, a sediment of jellified paint will cling to the bottom, leaving perfectly clear brush cleaner which can be poured off and reused again and again. Which brings me onto brush cleaning .
It's too easy to spoil your expensive brushes by cutting corners. After use, you need to rinse your brush several times until the cleaner is gin clear. I keep several jars for this purpose, each one rinsing the hairs cleaner than the previous, and all to be recycled . Allow the brush to dry in an upright position, but not supported on the hairs.you can drill a hole in the handle to suspend it on wire. The most diluted paint will accumulate in the metal ferrule, causing an irreversible stiffening of the hair which will alter the brush action. If you're painting over a long period , when you stop for a break, the brush cleaning can be postponed to the end of the day or even overnight by wrapping the end tightly in cling film to prevent hardening.
These are only my findings, based on many years of experimentation and more than a few bad paint jobs. I'd be pleased to learn from anybody who wishes to share somea➤ce.