Celica Forums General Discussion Exterior Powder coating

Using gas (natural or LPG) for a powder-oven is no problem as long as you keep following points in mind:

- When using gas, always use indirect heating system e.g. an heatexcanger. This is to prevent the flame residues to come into the oven itself

- For small ovens, especially small chamber type ovens, temperature control with gas is less accurate than with electric heating.

Oven
You must have access to an electric oven or toaster oven other than the one used for food, as mildly toxic fumes are liberated from the powder while curing. Used ovens can be found in appliance centers, news papers, and yard sales. The oven must be in good working condition.

Industrial ovens have open flames so don't worry about flammable fumes. ...

How is the Powder Applied?

The application process involves applying a charge to the dry powder particles and spraying them onto a grounded substrate. The substrate, or part, is typically grounded through the conveyor or hanger holding the part. The powder, once attracted to the part, is then held on the surface until it is melted and cured into a smooth coating film in the bake oven. The spray process takes place inside a booth designed to contain the oversprayed powder and makes it possible to collect the overspray and ultimately reclaim it for reuse.

The powder is fed pneumatically out of the powder container, or hopper, into the powder applicator, or gun. As the powder exits the gun, a low amperage, high voltage charge is applied to the powder particles, causing them to be attracted to the grounded workpiece. This attraction may even cause the powder to "wrap" around the piece, coating the back side.

The oversprayed powder, suspended in the air contained inside the powder booth, is then passed through a separation process that permits the powder particles to be retrieved from the air. The clean air is fed back to the work environment, eliminating the need for air make-up. The reclaimed powder is mixed with a proportionate amount of fresh, virgin powder for reuse achieving consistent results and up to 98% material utilization.