I just got off the phone with an operator asking if I had a component that could focus a jet of air at the mirrors during the drying process. Bewildered, and imagining mirrors, not designed to handle direct shots of air, flying through the tunnel, I asked him what he was trying to accomplish. Turns out he had a problem with mirror drool, the insidious foam caught behind mirror housings that leaks out as a car drives off. Turns out I’m getting these calls at an accelerating rate. Turns out, many operators, having added foam applications to their wash packages to boost their average ticket, miscalculated the requirement for additional rinsing. Leaving mirror drool on a car is perhaps one of the worst things you can do as a professional car wash operator. Customers may forgive missing a spot on a wheel. Most will tolerate a few residual water drops. Leaving foam behind that drools down the side of the car, or worse, up the side window as they drive away, however, will drive them to your competition. Delivering a perfectly good wash and destroying it by leaving residual foam is like nailing your own feet to the floor. The problem is with rinsing, not drying, and has a clear path to troubleshoot and fix. Proper rinsing of a vehicle requires five distinct steps. If you’re not already familiar with them I’d suggest reading on before installing your next foamed, premium pay wax. Let’s take a look.


Yes, you read that correctly. After the first friction wash in a typical hybrid tunnel package, you’ll find a high-pressure wash. Sure you may still be applying more foamed waxes after the high-pressure wash, but washing the car with streams of water isn’t the only thing happening during this step; you’re also transitioning from soft to hard water. A properly configured distribution panel will mix all chemistry with softened water prior to application. This improves the function and foaming of the chemistry, but makes the foam more difficult to rinse away.

Your high-pressure wash will normally be fed first from a combination of spot-free reject, reclaim, and fresh water. In most locations, water, having traveled through the ground and picked up plenty of minerals, tends to be hard. Although hard water is your enemy when mixing with chemistry, and will leave spots on the vehicle when not dried, it’s your best friend to deactivate the soft foam you’ve already applied to make it easier to rinse off.

The first step in attacking a mirror drool problem is to blast the hardest water you have available behind the mirrors. Plenty of manifolds are available on the market. Some spin, some are fixed, some have wide patterns, others narrow. One size will never address every make and model of vehicle in your market. You may have to experiment with various manifolds and where you position them in order to effectively de-foam the majority of mirrors. You may also have to experiment with various water sources for your high-pressure blasters. My starting point for any new wash with “normal” city water is to use spot-free reject water, which is some of the best water you have, on top blasters and mirrors, and “clean” reclaim water on sides. Depending on the hardness of your city water, once you’ve maximized your ability to neutralize foam in mirrors with your high-pressure wash, it’s time to move on to actual rinsing.


This is the step that seems to trip up most operators with mirror drool problems. A common configuration for years has been to have four water manifolds with 8 GPM fresh water followed by 4 GPM drying agent, 2 GPM sealer wax, and 2 GPM spot free. Every car got the same rinse and rarely was there a complaint. Actually, it may have worked too well in that many washes I visit have cut one or more steps over time. Now enter the era of multi-step premium foam applications. There’s no question that customers love seeing application after application of colored, scented foam, and are willing to pay for the premium shine, but getting all that foam off has become increasingly problematic. Like it or not, to remove the extra foam, you need to increase both the volume of water and potentially the quantity and position of your fresh water rinse manifolds. Gone are the days of one rinse fits every car. If you’re applying sheets of foam, you absolutely must increase the rinsing on cars receiving the service. Most operators are adding a supplemental fresh water rinse with dedicated mirror rinse manifolds that only activate on the top packages. Some are differentiating the function on a separate arch with lighted signs and featuring the extra step as a feature of the top package. If you’re experiencing mirror drool, look here first. Chances are you need to increase the capacity of your supplemental fresh water rinse to solve the problem.


I won’t pretend to be a chemist, but in layman’s terms drying agent makes the surface of the vehicle “hydrophobic” which literally means afraid of water. It helps water to pool and break off the surface making it easier for your drying system to remove residual droplets. Here’s the catch: It works its magic best when the surface is perfectly clean and free of detergent. That means, if you don’t remove all the foam before applying your drying agent, it will not perform as effectively, and you’ll have to use more energy from your blowers to deliver a dry car to the customer. More energy is another way of saying more electricity, and just one more example of how all the equipment and chemistry at your wash are designed to work together.


Some drying agents promote themselves as both a drying agent and sealer wax in one, and many operators use a single product for both functions. The two products are similar, but I prefer to use a distinct drying agent with a formulation only to bead and break water, followed by a separate sealer wax that also enhances sheen. Every chemical manufacturer has different offerings, but if you’re still struggling with mirror drool, consult your supplier about applying a separate sealer wax after your drying agent, some of which include de-foaming additives.


Some operators don’t want the extra expense of using spot-free water. Other operators charge extra for the service. Over the years I’ve changed my thoughts regarding spot-free water. Today, I only promote the spot-free rinse as a feature in my top wash package, but include it on every wash, applied from both rain bars and dedicated mirror rinse manifolds. Some operators will argue that it’s an unnecessary expense. I consider it a form of insurance that my customer will be satisfied with the finished product for days to come — until their next visit.


So there you have it. Like most things in this industry, there’s more to getting a perfect car than meets the eye. Solving mirror drool issues can be tricky. It often occurs only on certain makes and models of cars in your market. Issues can vary with changes in city water quality you weren’t even aware of. Unfortunately, not only is mirror drool a moving target, it also most affects your highest paying loyal customer base. Develop a plan to stay on top of it, or it will nail the growth of your wash to the ground.

Washing cars for over 30 years, Anthony Analetto serves as president of SONNY’S The CarWash Factory, creator of the Original Xtreme-Xpress Mini-Tunnel, and the largest manufacturer of conveyorized car wash equipment, parts, and supplies in the world. He can be reached at Aanaletto@SonnysDirect.com or at (800) 327-8723 ext. 104.