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Priming issues

A couple of things I see here I want to clarify
First.... all caulking is elastomeric. That simply means the material can expand and contract which is the main attribute and need for gaps.
Second.... you should be using oil based primer not water based. This is not needed for drywall but all raw wood and all exterior work should be primed with oil.
You should prime before caulking. Primer is designed to penetrate the fibers of the wood creating a physical bond as it is imbeded into the fibers. A physical bond is stronger than the chemical bond of the paint. Priming first also give the caulk better adhesion.
The good news is that you do not really need the caulk to be primed as the paint will stick to it well unprimed. If the alligator look is showing through sand it or use an exterior paint as they are thicker and can fill in the little cracks better. Oudoor paint can be used indoors but not vice versa.
As a former coatings chemist I can tell you that products which are greener are almost always inferior. If they were not the non green product would be discontinued. Manufacturers are always looking to replace harsher solvent based adhesives with water based adhesives so if you see the harsher solvent based product it is because it is better....almost always.
The two major causes we see in analysis of coatings failures are contractor application errors and choosing the wrong materials. The wrong material are often prompted by going green (water based primer #1) or focusing on looks over the function of the coating system. Paint is far more complicated than people could ever imagine. The manufacturers have endless hours of development invested. Follow their directions and you should be okay for the DIY project. I recommend using one brand for everything. They will work together as they are designed to do so
Pinelle Painting Services is a southern NH northern Ma based painting business. We offer worldwide consultation on coating failure analysis. We are run by two Chemical Engineers who come from the construction and aerospace coatings industries. The consulting is listed as Pinelle Construction Sciences.
Really baffled with a coating problem? Give me a shout it is what we do. [email protected]
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