Our Kynar Line can accommodate parts 24’ Long x 36” Wide x 90” High.

Kynar coated powder coat finishes create a long-lasting protection against weathering, aging, and pollution on architectural, commercial, and residential buildings. Here are some precautions to keep in mind:

• Flat sheet, leveled and sheared, may coil when baked, causing tolerance issues.
• Welded or stud welded attachments may cause flat sheet to distort or break metal when baked.
• Solution entrapment from the pre-treatment process can be problematic to assembled parts. If material carries water, it must be drilled to allow drainage of the water in capture areas. You should make provisions for this prior to sending for finishing.
• Tubes with welded ends rarely are usually not sealed and water will leak inside the tube.
• The heat from the baking process may distort radius material out of tolerance.
• If extrusion wall thickness varies on your project, color uniformity may occur. If a heavy walled extrusion is painted with a thin bead die, the bead die may over-baked, resulting in a darker appearance and lower gloss, as well as warping of the metal.
• Linetec’s pretreatment system is not equipped to remove non-water soluble oils. These types of oils contaminate the system and cause “fisheye” problems with the paint finish. Fisheye is a defect in the paint film appearing as a circular depression resembling a crater but not revealing bare substrate.
• Storing metal outside prior to painting can cause corrosion that must be removed.
• Residue from lead and wax used in the rolling process of tubes and extrusions will cause contamination problems if not removed. The lead and wax may run out in the baking process and cause damage to the paint finish and metal.

Faraday Cage Effect

The faraday cage effect is the electrostatic force that prevents charged particles form penetrating into recessed areas.

Limitations due to an electrostatic painting system might make it impossible to achieve minimum recommended dry film thickness on all areas of an extrusion. Areas subject to the faraday cage effect are inside corners and recessed areas such as channels and cavities.

The following criteria defines Linetec’s acceptable quality level resulting from faraday cage effect.

• If recess depth is from 50 – 100% of the width, there will be color coverage within the recess, but less than the specified dry film thickness.
• If recess depth is from 100 – 200% of the width, paint will be present, but the substrate may show through in some areas. The deeper the recess, the lighter the coverage will be within the recess. The substrate exposure will be less noticeable on pastel and light colors, and most noticeable on dark colors.
• Recess depths greater than 200% of the width may not have any paint coverage at the bottom of the recess.

Racking Options

The first stage in the powder coat process is racking the material. Racking is a critical step; it ensures the automated spray bells and the painters can achieve good coverage on all exposed areas.

• All material processed through the paint line requires some method of racking. Whenever possible, marks left from racking will be in unexposed areas.
• Racking for paint application: Always let the applicator know if touch-up of rack marks are acceptable when it is required to rack on an exposed surface.
• A one half inch border is required for racking of flat sheets. Clipping or hold punch are other options for racking of sheet material. The half inch border must be along the long side of the sheet when the dimension is greater than five feet.

Prints and Exposures

Up to date die drawings with accurate marked exposures is critical to a coating applicator.

Linetec defines an exposed surface (exposure) as the surface area indicated on a material shape that requires finish coverage. An exposed surface area, when assembled into doors, windows or other assemblies, is either viewable or in direct contact with environmental weathering.

When material is painted, accurate exposed surfaces must be supplied so rack marks can be kept to a minimum on the exposed areas whenever possible. Rework and double runs are minimized when accurate exposures are provided, thus minimizing the impact on lead times. The amount of paint in-house blended or ordered from the vendor is determined based off the total square footage of exposed surface areas.

Square footage, in most cases, is calculated based on a parts indicated exposed surface.

Calculation of a painted exposure, per lineal foot, is calculated using the exposed surfaces indicated on the print.

Exposed surface calculation may vary depending on the type of exposure, such as a single adjacent exposure on one profile or multiple non-adjacent exposures on the same profile. Exposed surface calculation may also vary depending on the material profile or type. Exposure calculations are subject to established minimums.

Primary Exposure is the exposed exterior and interior surface that must withstand the effects of the environment and normal use and wear. The primary surface must comply with all applicable AAMA specifications.

Secondary Exposure are semi-exposed areas requiring paint coverage, but which are not exposed to the direct effects of the environment or use and wear; this would include recessed channels and tracks. Semi-exposed, or secondary exposures, requiring paint coverage do not have to be in compliance of the AAMA specification. Minor blemishes such as runs and bubbles may be present and will not be rejected or touched up. Rack marks may be evident in secondary exposure areas and will not be touched up.