Professional Carwashing & Detailing

Whipping wheels into shape

July 1, 2011

Any operator can tell you, wheels are one of the hardest car parts to clean in a conventional carwash. And, honestly, that makes sense. Wheels are often exceptionally cruddy because they actually come in contact with the road. Wheels find it easy to get filthy when they frequently fjord through puddles, mash through mud and dig through dirt. And, if you add in a thick, dark coat of pesky brake powder, you’ve often got a magnificent mess rolling into your carwash.

In the carwash market, a lot of thought has gone into finding the best way to clean up this mess. While the traditional wheel cleaner was nothing more than a soapy towel and a helping of elbow grease, today there are plenty of automated wheel cleaning options available. Many companies have invested years in chemical formulation and product creation, and the results reduce labor needs and make sure customers leave with shining, sparkly wheels.

Cleaning with chemistry

Mark Weiss, senior chemist, with Blendco Systems said there are five major chemical mechanisms needed for a chemical wheel cleaner to successfully remove dirt and brake dust: Surfactants, solvency, emulsification, foaming agents and water hardness control.

The first and most important mechanism for cleaning a tire is wetting and soil penetration to loosen the soils. Weiss said the chemicals that perform these functions are called surfactants. While soil films typically repel water, these surfactants help to make water “wetter” by overcoming the beading effect and allowing the water and cleaners to spread across the surface. This is important because it allows the chemicals to better contact the soil so it can be removed.

The second mechanism is solvency. There are organic solvents added to wheel chemicals which actually dissolve certain soils like oils and greases. Acids can also act as solvents to dissolve iron and other particulate soils found in brake dust, according to Weiss.

The third mechanism is emulsification. Weiss said the emulsifiers help to break the oily and greasy soils up into smaller globules, and they help suspend the soils in the wash water for easier removal.

The fourth mechanism is chemicals that will affect uniform distribution and increase the dwell time. “This is essential when trying to remove these tough soils on these vertical surfaces,” Weiss said. “Foaming agents — which form a thick, stable foam as the cleaner is applied — will accomplish this by allowing the cleaner to cling longer to the surface when applied.”

The fifth mechanism, water hardness control, is essential. If hardness is not controlled, it will prevent the surfactants from doing their job. Even if a wash has a water softener, it is still important to control hardness because the soils that are being removed contain hardness ions which will enter the wash water.

Investing in chemicals

When it comes to using a top-of-the-line wheel cleaning chemical, Brent McCurdy, senior vice president with Blendco Systems, said the operator has to decide that they want a high performing product. Then, the chemical company can select a product and have support from the operator to invest in the top cleaning choice.

McCurdy also noted that owners should realize chemical wheel cleaners’ dilution ratios are nothing like other chemicals in the wash. Typical dilution ratios in a carwash can be 80:1 to 500:1. But, a strong wheel and tire cleaner should be as strong as 5:1 or 8:1. Often, most operators don’t want to spend that much money, so the competitive forces drive chemical suppliers to much higher dilutions and, subsequently, a much lower performance level on tires.

Today, McCurdy said the limitations in equipment, capital or cost per car openness has limited the potential for carwashes to see labor-free wheel cleaning. He said most full service operations make up for these limitations with labor at the back of the wash. An operator’s cost to use automation to really clean a wheel might include spending as much 15 cents a wheel. If the operator also invested in two CTAs and invested in high pressure and/or wheel brushes, they could ease their labor needs.

This article is the first in a two-part series dealing with the topic of wheel and tire cleaning. Part one deals with chemistry and chemicals. Part two will be featured in the August issue of Professional Carwashing & Detailing and will focus on chemical applicators and brushes.