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Tag Archives: colour matching

Color matching problems not related to the paint itself

Probably color-matching problems are among the most frequent paint defects in the car refinishing industry. It is also the main cause of expensive re-works and unhappy customers. In many cases, the poor color-matching is due to the darker or lighter appearance of the final result. Below I bring to your attention 6 parameters a painter should consider before the basecoat application:

Spray gun pressure

Unfortunately, many painters underestimate the importance of precise measurement of the spray gun inlet pressure. They either do not use a manometer at all, or rely on a poor quality analog manometer.

Outcome: Lower than designated pressure causes darker color result, while higher pressure – lighter color than needed.

Solution: Use a reliable manometer, preferably digital one, for each basecoat application job.

Humidity

Most of the paint manufacturers state the ideal humidity level for the perfect applications conditions. However, we do not have the possibility to control humidity levels easily. For your reference, ideal humidity level is between 30% and 50%, lower than 30% humidity is considered low, while higher than 50% humidity is considered high.

Outcome: Low humidity causes darker result, while high humidity – lighter result

Solution: Adjust viscosity based on the instructions from paint manufacturer, consider changing nozzle size and air cap with lower or higher air flow (consider switching between higher air volume HVLP technology gun and lower volume Devilbiss Trans-Tech or High Efficiency or SATA RP).

Temperature

Just like with humidity, every manufacturer advises the optimal temperature levels for the application. Unlike humidity, it is easier to adjust temperature levels in a workshop, but still there are limitations as well. As a rule of thumb, low temperatures can be considered the range from 15 to 20° C, normal – 20-25° C and high – 28-35° C

Outcome: Lower temperatures will cause darker results, while higher temperatures – lighter results.

Solution: Adjust viscosity based on the instructions from paint manufacturer, consider changing nozzle size and air cap with lower or higher air flow (consider switching between higher air volume HVLP technology gun and lower volume Devilbiss Trans-Tech or High Efficiency or SATA RP).

Thinning (dilution)

Every single automotive coating product comes with a detailed technical data sheet. Unfortunately, often painters either ignore those data sheets or simply continue to work with any new product the “good old way”. In reality, under thinning or over thinning will inevitably cause color problems.

Outcome: Under thinning will cause darker color shade, while over thinning will produce lighter than needed variation.

Solution: Follow the manufacturers’ technical instructions, labels and manuals. Use mixing cups with measurement marking, scales and mixing rulers.

Spray gun distance from the surface

Every sprayer has its own style and spraying technique, however certain standards must be respected. One of the parameters I refer to is a distance between the spay gun and the vehicle’s surface. Consider that normal distance lies within 15 to 25cm range.

Outcome: Too small distance will cause darker colors, too high distance – lighter variation.

Solution: Respect the advised distance between the gun and the surface.

Speed of spraying

Similarly, speed of paint application is very individual and varies from sprayer to sprayer. However, extremes are not good.

Outcome: Spraying with too low speed will cause darker colors, while spraying at excessive speed – lighter color than expected.

Solution: Follow the paint and spray gun manufacturers’ instructions.

 

6+1 reasons to put a paint mixer in a bodyshop

If we leave aside the size of each bodyshop, we could divide them into two categories: these with paint mix system installed and those without. The latter are using paint mixing services from their main consumables supplier. The percentage of bodyshops with a paint mixing machine in store varies from country to country; while in some markets a mixer in a bodyshop is considered a luxury, in some others it is a must.  After visiting literally hundreds of bodyshops around the globe, I have concluded that every bodyshop owner, regardless of the workshop’s size, will benefit from installing a paint mixer in his premises. Below I bring to your attention some of those benefits, as I see them:

  1. A bodyshop with a paint mixer installed will benefit from lower cost of the materials. Let’s face it, nothing comes for free, and if you use colour-matching services from a paint supplier, then you will be charged for it. Sometimes the difference between the costs per litre of paint can be as high as 30%. Too big percentage to be ingnored.
  2. Much faster vehicles’ delivery. The logic is simple; you do not need to drive to your supplier’s place in order to order the needed colour codes.
  3. Less material waste. If you have paint system within your grasp, you do not have to prepare more paint than you might need (just to avoid another trip to the supplier). If your shelves are full of cans with paint leftovers, than you should really consider how much paint is just sitting idle with slim chance to be used in the near future. Waste of money indeed.
  4. Better colour matching. If you prepare the colour yourself, the quality of colour matching will be much better. Of course, additional training will be needed (in fact all major paint manufacturers have colour matching trainings on a regular basis), but it is worth the time invested.
  5. You will enjoy better customer support from paint manufacturers. Paint mixer is a ticket for a direct contact and support from the paint manufacturer, including direct customer service line. In addition, you can count on regular visits and advice from the experienced technicians with a great baggage of knowledge.
  6. A bodyshop with installed mixer is perceived as more professional by the customers and, very importantly, by insurance companies. For fact.
  7. With paint mixer installation, you can expect some kind of gifts from your supplier. It is very common, when paint companies give freebies like spray guns, gun washing machine, infrared lamps, and free first toners loading up, scales or mixer itself. While it is not a rule, I have seen these kinds of “presents” quite often.

And what is your opinion?

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