Automotive Paint Inspection
PosiTest DFT Paint Meter

Paint Inspection Options

Until recently, consumers requiring an efficient and affordable means to inspect automotive paint thickness have mainly been limited to measurement solutions such as magnets, pen pull-off meters, and a few basic electronic instruments. Unfortunately most of these solutions have extreme limitations in accuracy, resolution and in some instances provide no quantitative results (i.e. only red, yellow or green lights). The largest drawback of many such magnetic instruments is their inability to detect paint thickness on aluminum.  Even on steel some magnetic instruments can be easily fooled by the addition of steel particles to the filler. When looking for minor paint thickness inconsistencies between panels (representing potential repainting), information provided by an instrument with only a 0.5 mil resolution and 1 mil accuracy is extremely limited.

DeFelsko manufactures the PosiTest DFT, which is a hand-held, non-destructive paint meter that is ideal for measuring the thickness of automotive paint on aluminum or steel automotive panels. The PosiTest DFT Ferrous is capable of measuring up to 40 mils of paint on steel panels, where as the PosiTest DFT Combo is available for measuring on both steel and aluminum panels. With 3% accuracy and a 0.1 mil resolution, either PosiTest DFT meter is capable of meeting the requirements of most paint measurement applications.

As an alternative, the PosiTector 6000 series of meters provide similar measurement capabilities, but with higher accuracy and resolution. Additional features such as memory and print capability are also valuable to customers with a desire to log measurement results. Based on the intended application, customized meters and probes are available that are specifically designed for measuring on steel, aluminum or both substrates.    

Auction Inspections

Inspectors at automobile auctions have a very limited amount of time to determine the true value of a vehicle. In addition to numerous other inspection points, they need to assess the quality of the paint finish and to verify that the condition of the vehicle matches its reported history, that is, determine if the vehicle has been in an accident or experienced other types of paint damage. 

Historically, inspectors have relied on visual inspections, such as checking body panel alignment and looking for gaps that might indicate bodywork has been done. Other alternatives include inspecting for signs of paint over spray on seals and body openings that might indicate repainting, as well as comparing paint color and finish throughout the vehicle. Unfortunately, subtle changes in color, texture or gloss often go undetected without a significant time investment requiring the inspector to view the vehicle at different angles and in different lights. Visual inspection techniques are particularly limiting in dimly lit areas, in bad weather (rain, sleet or snow), or on dirty vehicles.

Condition Reports are detailed legal documents that contain an inspectors assessment of any damages to the vehicle along with estimated repair costs and digital images if requested. The primary purpose of a Condition Report is to accurately communicate the condition of the vehicle to the consignor.  The report is a full evaluation of the vehicle's condition, and contains recommendations from the Condition Report Writers on Recon work that can or should be done to increase the salability of the vehicle. 

On-line sales further increase the need for pre or post sale detailed Condition Reports, as the consumer does not have the opportunity to verify the condition of the vehicle in person. Types of on-line sales now include: auction simulcasts where customers bid on-line against others physically attending an auction; Cyber (Smart) auctions where all bids are made on-line); Cyber lots (virtual automobile lots) where customers can browse and make purchases anytime); and dealer exchange sites that facilitates the buying and selling of wholesale vehicles (functions as an eBay for automobile dealers).

Why measure?

Paint thickness measurement is a powerful tool for finding evidence of accidents, patching of rust spots, and past paint repairs to delaminated surfaces. Unlike visual inspections, a paint meter provides a reliable and quantifiable measurement result. 

Problems under the paint will eventually develop with time, so that no matter how good the paint job, poorly prepared or damaged bodies will shorten its life. Thus a vehicle that has been repainted, regardless of the cause, can have a reduced resale value. The resale value decreases more significantly with hi-line and newer resale vehicles.

Inspection has the potential to prevent unplanned future repainting costs (up to $3000 for high quality repaint jobs). Repainting costs can increase significantly when body work is required to repair hidden collision or rust damage.

In addition, inspectors stake their reputation, future business and possible lawsuits on their judgments. If they fail to identify a vehicle that has sustained unreported damage or was rebuilt it can have a significant financial impact.  The relative low cost of paint thickness meter greatly reduces this risk, in addition to paying for itself due to increases in efficiency while inspecting.

Effective Use of a Paint Thickness Meter 

There are two basic considerations when taking measurements on a vehicle with a paint thickness meter. 

The first consideration is that even though the expected paint thickness may not be known for every vehicle type, vehicles should typically have the same thickness of paint throughout. Variations in paint thickness, even subtle thickness changes, can be indications of paint blending. Paint blending may be used to hide repairs ranging from minor paint touch ups for scratching to major body work such as clipping (welding two half vehicles together).  The Condition Report Writer should thus be looking for consistency within the vehicle, particularly within a panel. It is thus recommended that measurements be taken near all seams, approximately an inch from any edge. If a significant difference in thickness occurs between adjacent panels it is a strong indication that repainting has occurred.

The second consideration is to investigate prime spots for collision or rust damage. Due to moisture and salt, vehicles from northern climates tend to rust near the bottom, particularly lower door edges and panels subject to splash from the tires. Vehicles from coastal climates that receive ocean spray are more likely to rust around the hood, trunk and upper areas of fenders and doors, particularly near molding, handles and emblems. The middle area of fenders, rear quarter panels and doors are common areas for damage due to accidents, hit curbs, etc.

Once thicker readings are attained, additional measurements should be takn in surrounding areas to verify the results and to try and determine the reason for repainting. One of the primary advantages of using a paint thickness meter is the speed at which multiple readings can be taken. 

Who Needs to Measure?

The primary market for paint thickness meters is the $380 billion used vehicle remarketing industry. However, many of the same measurement principles and benefits exist in other automotive markets including body shops, painters, repainters, refinishers and detailers. Anyone with the need to control the amount of paint being applied or removed to a vehicle would recognize considerable benefits from a paint thickness meter.

Large auto auction companies have dozens of locations and thousands of employees, with the largest moving up to 9000 vehicles per week from a single location.  As part of their inspection, certification and reconditioning programs, auction houses often train and employ their own Condition Report Writers. Condition Report Writers may also work for specific dealers or as independents.

Similar to the Condition Report Writers found at auctions, many other professionals have similar needs for inspecting paint thickness as part of determining a vehicles value. For dealerships, the Used Car Manager is typically responsible for appraising and accessing the amount of damage to a potential trade-in.  Likewise insurance adjusters, professional car buyers and collectors have similar requirements.

Free Consultation

For current pricing or to order these instruments, please contact us by telephone (315) 393-4450, fax (315) 393-8471, or use our Online Request Form.  If you require additional technical information or have questions relating to your particular application, we encourage you to take advantage of our years of experience in recommending the best meter for your application.

Case Study: Detecting Paint Damage

The vehicle shown in Figure 1A had undergone significant body work on its right front panel. Even when notified that damage existed, the damage was not visually detectable by five trainees. The five trainees were then tasked with finding the damage with a paint thickness meter. By quickly taking measurements next to the various seams in the vehicle, trainees typically took less than two minutes to locate the damaged panel while pronouncing the remainder of the vehicle fit. 

Figure 1A

Figure 1B shows a seam measurement with the PosiTector 6000 FN1, whereas Figure 1C and 1D depict seam measurements taken with a PosiTest DFT Combo meter. The displayed readings were all in the expected 4.5 mils range and were compatible (+ 1 mil) to readings taken across the remainder of the vehicle. 

Figure 1B

Figure 1C	Figure 1D

Note that in Figure 1E a seam measurement taken closer to the bottom of the panel had a significantly higher reading of 11.6 mils. Moving further down the panel (Figure 1F) readings increased to a thickness outside of the range of the instrument (40 mils), indicating significant plastic filler. 

Figure 1E	Figure 1F

A review with the vehicle owner verified that bodywork had been completed to repair rust damage behind the front right tire, not unexpected for an older vehicle that has been driven all year round in Upstate New York.