Contact point for powder coating

Contact holes

Contact holes/drain holes are essential for compliant processing. If the customer does not carry out this preparatory work, AGRU implements the contact points for the powder coating and invoices for this based on the actual work completed. The customer must drill holes based on the following sketches:

Drain holes, which allow various pre-treatment fluids to drain off, need a bore diameter of at least 10 mm.

Drill the drain holes right at the edge (avoid dead corners and angles), as the frames are tilted during pre-treatment and pre-treatment liquid would otherwise remain in the corner area.

Please make sure that the contact points for railings, fencing constructions, etc., are created as installed (with the handrail at the top)!

Important notes
Visible surfaces

For powder coating of angled or flat bar stock material, it is essential to mark the desired visible surfaces on the delivery note. This also applies if the profiles in question are not supplied directly by you, but by various contractors.

If the delivery note does not contain notes and/or a sketch please note that angled sections will be coated on the outside, and flat material on one side, as a general rule!

When coating both sides or all sides of angled sections made of flat material, note that several contact surfaces are required for contacting.

If the visible side is not specified for sheet metal edged parts, sheet metal edged parts will be coated on the outside on one side, assuming we are able to identify the outside. If we cannot identify the outside, the parts will be coated on both sides as best as possible (invoicing will therefore also be for both sides).

Subsequent forming

If subsequent forming of the coated workpieces takes place, suitability must be investigated in advance. Micro-cracking in the powder-coated surface can lead to corrosion damage.

Please note in particular that in unfavourable storage conditions, the combination of water accumulation (e.g., under packaging film) and heat, can lead to cloudy white spots on the powder coating or imprints of the packaging film. This physical process, which can occur sporadically, is reversible by heat-treatment (e.g., post-curing in the oven, industrial ovens).

Further processing

Joint sealants and other auxiliary materials such as glazing aids, lubricants, drilling and cutting agents, etc., which will come into contact with coated surfaces must be pH-neutral and free from substances that could damage the coating. The processor must carry out suitability testing in advance.

Thick-walled profiles

The following must be observed when powder coating thick-walled profiles (where the wall thickness of one shell is greater than that of the other profile shell, e.g., bulletproofing profiles):

• When curing the powder film (at approx. 180–200 °C), the different wall thicknesses will result in different object temperatures (curing temperatures), which can lead to colour differences between the outer and inner shells.
• In addition, the two profile shells will heat up and therefore expand at different rates. Deformation of thermally insulated profiles can therefore occur (plastic web)! AGRU accepts no liability in case of complaints of this nature.