Paint Blocking - Causes & Solutions
Paint blocking, defined as two painted surfaces sticking together, can cause an awful mess. In some cases it can damage or even destroy the objects you are painting.
Causes
The simplest cause of paint blocking is when two freshly painted objects are allowed to touch one another while their respective paint coats are wet. Another example is when two freshly painted objects are placed in close proximity when the paint appears completely dry, but in fact is not. In these cases, the easiest and most obvious prevention measure is to keep the objects in question well apart from one another while the paint is drying.
Another cause of paint blocking is when separate, painted objects are forced to touch one another after their paint coats are indeed completely dry, whether such touching is from assembly or stacking. In such cases, even dry paint can slowly chemically react and bond with another painted surface, or conversely, spilled water or solvents can also cause paint blocking. In cases where painted objects are in close proximity with one another, one solution is to place a thin separation layer between the objects, such as wax or tissue paper or a thin layer of felt.
Heat and pressure
Heat and pressure can also cause paint blocking. In such cases, there are two possible solutions. The first is to paint such surfaces using heat or friction resistant paint, or to use a separation layer between objects, which are assembled together or stacked upon one another.
Solutions
When blocking does indeed happen, there are several ways of addressing the problem. The first is to ask whether or not the surfaces, which are stuck together, need separation. If they do not, then the situation, though sub-optimal, is harmless. However, if it does prove necessary to separate the surfaces, take great care to avoid damaging the objects themselves. Sometimes it is possible to carefully pry the objects apart, but other times, use of a solvent such as varsol is needed, as long as its use does not damage the underlying surface.
For the most part, paint blocking is one of those situations, where an ounce of prevention really is worth a pound of cure, and it is far easier to stop it from happening than to try and deal with it after it has already occurred.
Primers and Finishes
Priming is essential for better adhesion, sheen uniformity, mildew control and durability.
Select a top quality interior paint in the color and sheen of your choice.
Substrates, Primers
Substrate: Bare wood
Primer: 975 Acry-Plex Enamel Undercoat
Finish Coats: 1650 Acry-Plex Interior Latex Semi-Gloss
1685 Dura-Poxy + Int./Ext. Semi-Gloss Acrylic En.
1680 Dura-Poxy + Int./Ext. Gloss Acrylic En.
