As a customer you should be aware that flat sheet, leveled and sheared, may return to coil memory when baked in our oven, subsequently causing some tolerance issues.

Welded or stud welded attachments such as extrusions or break metal applied to flat sheet or break metal may cause the sheet or break metal to distort when baked. Once distorted, the sheet or break metal may not return to its original shape when cooled. Welding will almost always cause distortion on aluminum sheet that will be noticeable after painting.

Assembled parts may be problematic due to solution entrapment from the pre-treat process. If it is determined by Linetec that material will carry water, it will have to be drilled to allow drainage of water in capture areas. Drilling would not take place without customer approval. Making provisions for this type of issue is best left to the customer. Linetec can make suggestions your engineering may consider. 

• Enclosed tubes:

•     Typically tubes with welded ends are never completely sealed and water will enter inside the tube. Enclosed tubes will require drilling to allow for water drainage

•      If a tube with an enclosed end is completely sealed, heat from the baking process may cause the tube to distort or rupture. 

• Radius material may distort out of the radius tolerance due to heating of the metal in the baking process. 

If extrusion wall thickness varies significantly on your project, color uniformity may be at risk. This is due to the differential in baking to reach the metal temperatures required to cure the paint. For example, if a heavy walled tube is painted with a thin bead die, the bead die may be over-backed, resulting in a darker appearance and lower gloss, as well as warpage of the metal.

Contaminants

Our 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 ~ 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 may cause corrosion, that unless removed by sanding will cause staining and poor paint aesthetic quality

Residue from lead and wax used in the rolling process of tubes and extrusion will cause contamination problems if all the lead and wax is not removed. The lead and wax may run out in the baking process and cause damage to the paint finish and part.