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Chemical systems that clean up

October 11, 2010
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Most operators spend a significant amount of time prior to purchasing an in-bay automatic asking for feedback about different units. They talk to manufacturers, distributors, and fellow operators and discuss a variety of topics.

Seldom do the discussions come around to one of the most important issues; the chemical dispensing advantages, disadvantages and options.

What experienced owners know
Chemical dispensing and related equipment should be a major point of consideration when buying or using an in-bay automatic.

After years in the business, many experienced and savvy operators have learned that most equipment can wash a car well, but in the end, exemplary cleaning really comes down to the chemicals.

Some chemical dispensing equipment is not capable of reaching and maintaining detergent levels necessary for good cleaning.

Owners should consider how much time they spend discussing the chemical dispensing equipment as it relates to an automatic carwash when purchasing an in-bay.

Modifying management
When considering the purchase of an in-bay automatic it’s important to know what types of chemical dispensing systems there are available.

The problem is that many of these systems require modification to achieve quality results.

Operators may question why this is. The answer is simple — equipment manufacturers are experts on equipment, not on chemicals.

They are providing equipment that will essentially work; however, this may not mean the equipment is working at optimal performance.

Because many operators look for low cost equipment they sometimes either don’t or can’t compare the values of the chemical dispensing equipment.

Systems to consider
1. Soap tank and hydrominder with venturi: This is the original chemical dispensing method.

The detergent/protectant levels are monitored by a float connected to a hydrominder. The hydrominder goes through a venturi which creates a vacuum and pulls in the product.

Advantages: Proven, simple, measurable, highly adjustable.

Disadvantages: More expensive, water pressure can affect consistency.

  • How to optimize

Owners who have this system are usually pretty satisfied with it. These systems may be more costly to produce, but offer a pretty simple, reliable, and flexible approach.

The biggest problem with these systems is occasional overflowing and varying quality.

Overflow is caused by the float hanging up, but can be fixed by ensuring the float is free of obstructions.

Sometimes these systems need to be replaced or upgraded due to wear. This can be done with an investment of around $70 or less for rebuilding kits.

The varying quality is directly related to water pressure. The venturis that drive the suction need a minimum pressure and flow to achieve suction.

One simple approach to make this more accurate is to put in a small storage tank (50-100 gallons) and feed all the chemical systems with a pump that will maintain a constant pressure.

This way the incoming water pressure and flow do not affect the chemical concentrations. This can be done for as little as $200.

2. Chemical injection pump: This method utilizes an electric pump to push the detergent/protectant into a stream of water. Typically, owners can adjust the strength of detergent by increasing or decreasing the pump speed.

Advantages: Avoids the costs of soap tank/hydrominder, easy to adjust, and precise.

Disadvantages: When it breaks the owners won’t necessarily realize it, wear factors affect precision, chemical qualities are limited by the size of the pump, pump limitations (pressure and flow — the tradeoffs between these) can restrict whether owners can achieve strengths necessary for top performance.

  • How to optimize

One of the biggest problems with this type of system is achieving a quality presoak strength for use in automatics.

Typically, these pumps struggle at maximum settings to put on a strong enough presoak for top cleaning.

Many of these pump manufacturers make double headed versions of the pump (around $400) which are the easiest way to increase output.

Another option is to link two pumps together and create a double injection. A third approach is to convert this system to another one of the chemical systems mentioned here.

Owners should work with their chemical provider to titrate their detergents and compare them to a top competitor’s in the area to create some basis for whether they are in need of more detergent.

Regularly titrating and flow testing will help ensure that the system has not varied from the original settings.

3. Water driven injections systems: These systems work by using water pressure going through a high pressure venturi that sucks chemicals directly into a stream of water.

Typically, these are quite reliable because the water pressure is constant and based on a pump that maintains a targeted pressure and flow.

Advantages: Simple, accurate, inexpensive, reliable, and little to no maintenance.

Disadvantages: If driven by city water pressure (not common in most equipment today) it can fluctuate and sometimes not achieve the desired concentrations necessary for top performance.

  • How to optimize

Water driven injection systems on most newer equipment models are considered the Cadillac of chemical injections.

Most of these systems are inexpensive, easy to adjust, reliable, and adjust within a wide range of strengths.

About the only maintenance is wear — this happens over a long period of time or in extreme chemical strengths.

The only downside to this system is when city water pressure is the only pressure driving the action. Most current equipment using this type of system does not rely on city water pressure and is therefore quite reliable.

The unfortunate examples suffer from adjustability and accuracy problems due to water pressure fluctuation and/or difficulty in dialing in the appropriate suction rate.

4. Water driven pumps: These pumps use city water pressure to drive the suction of chemicals into the water stream. These pumps are advertised to be accurate over a range of water pressures.

Advantages: Less expensive than some alternatives, more flexible in a wider range of city water pressure, and simple to install.

Disadvantages: Expensive to replace, maintenance involved, and often underpowered for the application.

  • How to optimize

These systems are fairly new to the market and the jury is still out on them. At first they seem inexpensive ($200 or so) until owners look into sizes that are really needed for presoak and tire cleaner ($500-$600).

Furthermore, they are not immune to water pressure changes, although they do appear more flexible among a wider range of pressures and flow.

One of the biggest problems noted thus far with these is that most equipment manufacturers and pump manufacturers are not familiar enough with the pump sizes needed for top cleaning and, therefore, in most cases the wrong pump dilution size is recommended

These pumps also require some maintenance which many operators don’t keep up on as well as they should.

A conscious choice
In the end, all of these systems can be used or optimized to get a cleaner and better protected car, but this often can’t happen without an owner’s conscious attempt to optimize the system.

If you haven’t purchased equipment yet consider these items in your purchase criteria and identify a system that best fits your style and needs.


Brent McCurdy is a general manager and co-owner of Blendco Systems, LLC. Blendco Systems is headquarted in Bristol, PA. Brent’s email is bmccurdy@blendco.com.

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