Axalta

As most paint technicians will confess, their skills and knowledge are very paint-centric and sit at the opposite end of the spectrum to the skills and knowledge for, let’s say, an MET technician. In other words, painters are probably the least likely to show a desire to learn the complexities of another skill set. And to be fair, why should they?

Removal and refitting, wheel alignment, electrical testing, fault diagnostics, calibration – it doesn’t affect them, right? And this is considered especially true for SMART repairers.

Well, I believe that’s about to change because the rapid introduction of vehicle technology affects everyone.

The increase in hybrid and EVs entering the workshop is relatively straightforward in terms of technical challenges. Trained and qualified technicians are in place to safely disengage and reinstate when appropriate. But EV safety awareness training is critical for all staff – including paint technicians (be aware of baking temperatures and follow the guidelines, and don’t ever touch the orange high-voltage cables!).

So, what about ADAS technology? Why might it be important for paint technicians to gain an understanding of this subject? Paint can alter the capability of a radar or parking sensor by affecting what we refer to as “line of sight”.

The most likely area of risk is the rear bumper corners behind which blind spot detection radars are mounted, particularly if the damage is minimal and MET technicians are not involved in the repair. It will be up to the paint technicians to understand the vehicle manufacturers’ technology and follow the guidance in terms of applying layers.

So, what is the guidance? In most cases it is limited. Audi said that filler must not be applied within 25 cm of sensors; General Motors said paint thickness on ADAS-equipped bumpers must not exceed 330 microns, while Nissan said it does not support any repair, body filler application, or paintwork on rear bumper cover in the general area of side radars.

Generally speaking, VMs encourage replace over repair, but the reality is different; bumpers are still being repaired and painted, so it’s important to understand the safety parameters.

It’s all about microns. One micron is equal to one thousandth of a millimetre. A typical OEM finish will have between 100 and 180 microns of paint film thickness. In refinish however, we must allow for the fact that film thickness will vary considerably between products, paint manufacturers, operator techniques, spray gun set-up and a host of other factors.

But let’s keep it simple. In refinish, a typical primer should, after sanding, leave between 25 to 35 microns. A basecoat could be between 13 and 38 microns and a clearcoat can reach up to 100 microns. On average, that would give us a total film thickness on a refinished area of 155 microns.

But this is paint with no filler, and the OEM film thickness will already be around 150 microns. Of course, most – if not all of the OEM, finish will have been removed from the immediate repair area as part of the sanding and preparation process, bringing the film thickness back to acceptable OEM levels again after refinishing.

Surrounding areas further out from the immediate repair may reach a maximum of 300 microns (assuming no previous paint repair has been carried out to the same area).

In summary, the technology of vehicles is complicated and connected, and will influence the repair processes of everyone in the workshop. So, my recommendation is  to embrace the changes and challenges. Work with, not against, the VMs and learn as much as you can.