RESTORATION - Kawasaki Z1 Back to Restoration Menu
Chrome dents
Detailed information about chrome plating can be found in several industrial bibles. The Canning manual is a good one and original copies sell well on eBay.
Of more relevance to you are the pitfalls and necessary preparation for a good job
Exhaust pipes are a constant source of nuisance and account for ninety percent of the disappointment. Wheel rims and aluminium are similar.
A good exhaust pipe, free of dents will have chrome and nickel removed in a stripping tank. Subsequent immersion in a sodium hydroxide bath contributes to the removal of internal oil. Unfortunately it never seems to do a good enough job therefore the pipe should be stopped off and filled with decarbonizer.
Whilst carbon has little effect on the process, dry carbon deposits retain oil. Before chrome plating the pipe is immersed in a warm solution. The pre-clean encourages oil to migrate from the carbon into the solution. Start again.
Exhaust pipes with numerous dents can double expected costs. The pictures illustrate repairs, which are let in, pulled, silver solder, or braze repaired.
Both braze and silver solder snots are linished and polished. Ideally, there shall not be a witness ring around the repair perimeter. Careful polishing goes some way to meeting the ideal state but cannot be guaranteed.
Worse case example
A small number of dealers, RWHS Classic Bikes being one, pay for a quality service even when the job ends up scrap. They restored a H2 Kawasaki and brought the carbonized, dented pipes to myself.
After stripping, repair and letting in the exhaust pipes turned blue under the influence of a polishing wheel. Bluing indicates that the metal is thin often caused by previous chrome plating. Welded seams opened, were repaired and pressure tested. Total cost £800.
Approximately three months later pin pricks appeared on the surface of two pipes rendering them useless.
RWHS absorb these costs and so will you. I cannot indemnify you for these unfortunate circumstances.
Wheel Rims
Rims should be placed on a surface plate or piece of glass and checked for twist. Spoke tensioning will not remove or realign the rim edge.
Most tyre lever marks can be removed but identification numbers should be left alone.
Aluminium
Successful chrome plating of this metal is difficult for jobbing shop chrome platers. Polished parts are nickel-plated followed by chrome. The stress of chrome deposition causes the bond between nickel and aluminium to fail. Several months later chrome strips can be pulled from the casting.
Without knowledge of the aluminium type the jobbing shop will deposit chrome at the wrong voltage.
To be continued...