Having decided my beloved Univega was going the 1x9 route; I stripped the LX cranks and gave them a seriously good clean. Despite regular cold water rinsing and hard paste waxing, the salt monster had left his pock marked calling card in the anodised finish.
To make matters worse, after almost twenty years, the flamboyant red enamel was starting to chip all too easily along the chainstays. Up until now, this recession had been held back with decent quality nail varnish but now demanded more remedial action.
Maldon Shot Blasting & Powder Coating www.ctc-powder-coating.co.uk replied to my SOS email, confirming they’d be happy to sort.
Tuesday afternoon, I needed a break from the keyboard, so stripped the frameset bare and attempted to chase years of waxy home brewed frame preserve from its inner sanctum. This would, theoretically minimise the amount of prep the team had to perform before blasting and ultimately painting.
Since we’re on the subject, be sure to tell your frame builder/spray shop there is Waxoyl, or similar preserve sloshing around inside. Otherwise, with the introduction of heat, it will become molten, race from the tubes and potentially scald them!
What lies beneath.....
Graham and Chris were taking no chances. When the industrial degreaser didn’t do the business, my frame was immersed in their methyl chloride tank for a few minutes...As the honey coloured gloop dissolved, racing to the surface in a raft of brown bubbles, those relatively thin enamel and primer coats followed suit.
Much to our surprise, the Alpina 506’s tubes were also sporting a layer of corrosion busting nickel.
Though less of a slippery customer and kinder process than Chrome, chances are the factory enamellers had to use acid etch primers to persuade the paint to stick. It would also explain why, despite high, hell and high water mileages, seemingly bare metal hadn’t succumbed to the elements.
This was easily dismissed in the Iron oxide cabinet before the surface was treated to an even finer polymer bead... Next came that zinc rich epoxy powder primer. I’d plumped for cream this time round, classic and understated. Would coordinate with the bike’s existing kit perfectly too.
The zinc was cured at 150 degrees for 15minutes; cooler than text book and forum lore would suggest. I’m told the lower temperature achieves optimal fusion between the primer and colour coat.
Higher temperatures would result in a more brittle finish, prone to chipping.
I’d gone for poly gloss buttermilk, which requires particular care. Though the flow rate ensures even coverage, flawless results are difficult given its tendency to drip and run during oven curing. This is also goes for other paints with low pigment.
Even when stored correctly, powder paints eventually “go-off”. This can result in a lumpy; or flawed final effect. Some tell-tale shadowy dimpling had struck along the down tube. Job-lot finishers would probably pass this but Graham was having none of it. Imperfect areas sanded, he disappeared in search of a match and returned with a small tub of “Interpon 610 cream”.
Initial inspection suggested a peachy pigment but testing on some scrap proved otherwise. A full account is coming up in Seven Day Cyclist www.sevendaycyclist.com but for now, I’ll leave you with this photo-love story. Fancy something similar? A single, standard colour, such as this cream including blasting and zinc based primer start at £65. What’s next? Those refurbished cranks, of course.
