Metal Finishes

Learning Intention:Understand how and why metals are

finished

Finishes on metals are used to both protect and decorate the surface. If left unprotected most metals tarnish and eventually corrode.

Preparation

• No matter what finish is to be applied, it is important that the surfaces are clean of dirt and grease.

Dip coating

• involves covering metal with plastic

Electrostatic Powder Coating

• Uses a spray gun, which applies an electrostatic charge to the powder particles, which are then attracted to the grounded part. The parts then enter a curing oven

Fluid Bed Powder Coating

Preheated parts are dipped in a hopper of fluidizing powder.The coating melts, and flows on the part. Post cure may be needed

Electroplating

• Gold plated

• Silver plated

• Chrome (chromium) plated

• Tin plated

• Zinc plated

Electroplating

Galvanising

• Galvanised steel or aluminium is metal that has been coated with zinc in order to prevent rusting / corrosion. This can be done using a hot dip galvanising method or electroplating

Anodising• Aluminium is typically anodised . It is done to make it more durable and

decorative

• Polished• Etched• Brightened• Coloured• Sealed

Enamelling

• glass is ground to a fine powder, then laid onto a metal surface and fired in a kiln at a great heat to make it melt and fuse

Spray Paint

Test Yourself

What preparation is needed before applying any finish?

What finishing process has been applied to this aluminium bucket and why? What has it been coated with?

What are the 3 main reasons metal is finished?

What finish has been applied – and how?

What are the two main ways to apply a powder coating?

• Electrostatic• Fluid bed

What type of finish has been applied and why?

Briefly describe what enamelling is