Showing posts with label Scapin. Show all posts
Showing posts with label Scapin. Show all posts

Sunday 1 May 2016

A Slippery Scapin's Starry Makeover





Increasingly superseded by stainless, chrome has long been synonymous with Italian manufacturers, despite Columbus recommending their tubesets were not subjected to acid baths, filing and similar torture...

Scapin are an Italian marque, renown for coating their steel frames internally with phosphate and nickel plating the exterior tubes. Allegedly, this was also for corrosion resistance, though I remain convinced aesthetics were the biggest pull. This particular example came under my radar, while I was mooching around Maldon Shot Blasting & Powder Coating’s bat-cave.

Closer inspection suggests it was fashioned from Columbus’ thin wall Nemo or Genius tubing. I strongly suspect it was originally part-painted like this Rossin but chemically stripped once the livery had begun losing its tenure and/or succumbing to stone chips and other cosmetic damage.   

Persuading stove enamel and 2pac finishes to stay put on partially/ plated framesets has presented headaches a plenty for paint-shops. Acid etch primers ruled by default but given a few years’, the livery tends to flake and peel where the two overlap.

This customer has chosen to leave the rear triangle in its original polished state. Aesthetics aside, this means chain slap and hasty wheel removals won’t leave unsightly calling cards. Graham carefully mummifies these with masking tape to rule out any pitting from blast media.

Having passed the threaded uni-crown forks through the iron oxide cabinet, Graham decides to sand the main triangle. He fears even a gentle grit could lift the nickel in places, which is not something that can be disguised with additional paint. 

Instead, he opts for an epoxy based zinc primer. Epoxy offers superior adhesion and interestingly, resists chemical attack better than others. However, they aren’t UV stable; hence polyester powder is the good finisher’s choice for colour coats.

After meticulous plugging and masking of head, seat tube and threaded areas, the frameset disappears beneath a powdery grey mist. Seven minutes and some perfectionist re-touching later, its spirited off for a ten minute bake in their gas oven.

Monitoring progress around the seven minute mark, the powder has melted to a rich (and strangely attractive) grey skin. Next; Graham applies a gloss black, a common “colour” that including lacquer brings the price to £65 plus VAT. However, this is only the base for a very exotic commission.

Four minutes and some localised re-touching later, its back to the curing oven for another ten minute bake; I alter the camera settings slightly and sip some tea, while Graham heaves a huge box of powder across the workshop dung beetle fashion. “Sapphire Star clear coat” he shouts over. 

I’m told this acrylic is impregnated with tiny pigments of colour. The overall effect is timeless petrol blue under normal lighting but assumes a subtle sparkle on sunny days. It’s well known that colours have slightly unique characteristics, requiring different techniques but Graham explains; particular care is needed with this kind of specialist clear coats-including temperature. 

The Scapin must not be allowed to cool, otherwise crazing or clouding is on the cards-disastrous. Gun loaded with lacquer, he strides purposefully over to the oven, caresses the frame tubes, nods with a grin and retrieves the frameset.  

Powder lacquers always appear white, enabling the sprayer to see exactly where they’ve been. Anything other than exacting coverage here will ruin the effect but like any skilled trade, he makes this look effortless-done in five minutes. 

Back to the oven for another ten minutes, we’ve time to indulge in a biscuit; or three. Graham removes the masking tape while the adhesive is still soft and I get a final shot.  
Total cost is £162 including VAT.