What are some causes of loss of adhesion?
Inappropriate uses of stain
- Lack of raw wood sanding (white wood sanding)
- Lack of intercoat sanding
- Oily stains were not adequately dry prior to first coat of finish (often caused by not removing excess stain after application
- Shading or toning with only stain leads to pigment obstructing a mechanical bond (suspending stains in a thinned topcoat can help adhesion)
- Using a softer sealer coat can lead to wrinkling or cracking in the topcoat.
Example: Using a nitrocellulose sealer beneath a conversion varnish topcoat.
What are some causes of poor atomization?
- Too little fluid pressure under-atomizes the material
- Too large of tips deposit too much under-atomized material
- Worn equipment causes unequal distribution of sprayed material
- Viscosity that is too high for equipment leads to poor atomization and lack of material
- Basketballs vs. Marbles
- Finer atomization leads to better hide and film development
- Larger particles can hinder color development and proper film formation
Why am I not achieving consistent color?
Color vs. strength of color
Raw Wood (white wood) sanding is inconsistent, leading to different amounts of stain deposited on the wood
- The color is correct, but not enough has been applied. Opaque colors that have not achieved full hide can look different
- Concentrates may not have been properly reduced, leading to too much color being applied
What is causing fish-eyes on my project?
Most typically caused by surface contamination
Occasionally caused by poorly maintained equipment
Rarely caused by contaminant in product
- Oil in air lines is most common
- Silicone oil in lubricants could also be a source