ONE MUST Understand Paint Before One Paints!

Paint is like caulking.  There are many kinds of caulking and the right material must be used for the right application.

Similarly, there are many kinds of paint, and the right paint must be used for the right application.  ONE MUST understand paint before one paints!

Should I prime first?
Should I spray the paint, roll it or brush it?
Should I use oil or latex?
Should exterior paint be avoided indoors, and can interior paint be used outdoors?
Should I apply one or two coats?

Example in point.  This gave me a chance to actually teach my client.

This is a layer of paint peeling over another layer of paint.

And it peels easily, with just a swipe of the palm of the hand.

And the layer underneath is perfectly intact, without any peeling whatsoever!

How is that possible?

THIS IS POSSIBLE BECAUSE THE WRONG PAINT WAS USED!

WHY WAS THE WRONG PAINT USED? 

BECAUSE WE DON'T KNOW WHAT WE DON'T KNOW.

And for all I know this could have been a "PROFESSIONAL" who applied this most recent coat of paint!

So what happened?  Why all the peeling paint?

The top layer of paint is peeling because, BECAUSE, it is a layer of latex paint over a previous layer of oil-based paint.

Latex paint does not adhere to oil-based paint! 

A professional is supposed to know that.  The key word, of course, is supposed.  A homeowner painting for himself would know that, BUT ONLY IF THE HOMEOWNER READ THE LABEL FIRST!

Who needs labels?

Having done this creates a big problem.  How much of the existing, visible second layer of paint is latex over oil-based?  We don't know!  And it all has to be removed!

What should have happened?  I know what oil-based paint feels like, as opposed to latex.  I also know what latex paint feels like, as opposed to oil-based.  But even still, before one paints, one must, THAT'S MUST, check to see what kind of paint is being painted over!

HOW CAN WE TELL IF A COAT OF PAINT IS LATEX OR OIL-BASED?

Nail polish remover has acetone in it.  Acetone melts latex-based products.  Take a rag and a little nail polish remover and rub it over a small spot of the paint.  If the paint comes off onto the rag, IT'S LATEX!  If it does not come off, IT'S OIL-BASED!

DOING THIS IS BEST PRACTICE!

Then your next layer is applied accordingly.

To throw another wrinkle in it, oil-based paint can be applied over latex, BUT MAKE CERTAIN THE UNDERCOAT IS STRONG, INTACT AND NOT CRACKING!

My recommendation:  people rarely use oil-based paints anymore and some retailers don't even carry it!  But, still, you must check to see what you are painting over.  And if, on a tour of a home, paint is peeling in an odd way, INDOORS OR OUTDOORS, it might just be because the wrong paint was applied! 

Now you know...