How to Diagnose and Cure Early Clear Coat Failure

Tags: Clearcoat · Paint Defects


http://www.howtopaintcars.com/wp-content/gallery/paint-defects/clear-coat-failure.jpg?i=96595913Early Clear Coat Failure is a common problem that is often seen on new vehicles of specific make and model or repainted vehicles where there was a problem during the painting process.

Early failure of clear coat should be differentiated from standard UV and Wind damage that all cars can suffer from because it happens either immediately or very soon into the vehicle’s lifespan.

A normal good paint job performed in factory settings should last the average customer around 10 years maybe more without adhesion loss or break down of the clear coat finish.

For Repainted Vehicles the life of the repair is related to the type of repair made but on average a minimum life for a spot paint job would be about 3 to 5 years with an overall paint job lasting somewhere around 4 to 7 years.

If a paint job begins to fail within the first two years the likelihood that there was a problem in the process is pretty high.

We have all known different car manufacturers that have released models that have serious paint defects. Some of these car lines have caused so many problems for the customers that callbacks and class action law suits have been successful in getting manufacturers to cover the cost of repainting vehicles.

Why does early clear coat failure happen?

The majority of thought about why clear coat fails and studies by paint manufacturers reveals that there are three main causes for early clear coat failure.

The first problem is improper paint chemistry. The improper amount of activator in urethane clear can cause post delivery problems.

The second and third reasons for early clear coat failure are due to improper methods of application.

The first is improper flash times between both all layers of paint. This is probably the most common mistake is improper flash times between clear coats because the technician is trying to keep the surface wet so the clear will flood any defects on the surface of the vehicle and self level.

The second and less likely problem is if there are too many coats of base / color coat then improper flashing between the base and the clear will cause solvents to outgas and cause poor adhesion  between the base and the clear. This is not a problem if you wait the proper time before applying your first coat of clear.

How can these problems be prevented?

The most important thing that you can do to prevent early clearcoat failure is to follow proper flash times between all coats of base and clear and pay close attention to the final flash of base before you start applying clear.

I normally take a short break when doing overalls or even large spot jobs just because I need the break but if you decide to push through and get the job done too quickly you could end up with this problem.

The final solution is making sure that you mix your clearcoat correctly. Always follow the Technical Data Sheet information supplied with your paint.

Never try to compensate for cold conditions by adding more activator or hardner.

How do you repair early clear coat failure?

As you might guess the only solution to clear coat failure is sanding and reapplying paint.

If the problem is found on a spot repair you should redo the whole repair.

If the problem is on an overall job and only one area is beginning to fail it is in your best interest to repaint the entire vehicle so you do not have additional call backs in future months.