What part of the cars are left dirty - only the sides/rockers? You said "mostly" the rockers, but are there other parts?
Is it dirty sections of the car that look like they have been missed, or is there a general film left on the car?
Are you high pressure prepping? Are you using a presoak followed by high pressure?
Do you towel dry? Does the towel dry take care of anything left, or is the dirt too heavy/prevalent?
Are the employees missing the lower parts of the car because it is difficult/tiring to bend to reach them? Are you using wash mits? Will switching to a boars hair brush help them to reach to the lower part of the car?
A set of low wheels will certainly help, but I'm assuming you hand wash because you have a customer base that prefers that type of wash. Once you add the side wheels, you are no longer purely a hand wash.
Just a few thoughts before you start to automate your line.
1. The sides/bottom especially when the vehicle is black, you can see all the spots that were missed by hand washing.
2. It is a combination of film and dirt. When the vehicle is washed, if any spots are missed you will see it when it is being towel dried.
3. Our procedure is: Pull vehicle in tunnel, brush the wheels, high pressure rinse the vehicle/wheels, prep brush with extra long and large hog hair brushes. Then the employee fires a roller, it goes threw a pre-reclaim rinse and soap arch, then it is hand washed with wash mits. (We are prepping and hand washing)
4. We do towel dry ( we are a full service car wash) If some small dirt spots are missed the guys will just wipe it off. If the car is too dirty we will bring it around again to wash (which I am so fed-up with)
5. The employee's do miss the spots. Why? many reasons: Lack of care, a lot of tiring labor, minimum wage. The list goes on and on. If a car comes in dirty and if any spots were missed by either the hog hair brush or wash mitts, you will see it when the car is pulled out of tunnel.
6. I am located in Los Angeles where everyone has this perception a machine wash will scratch their car. We have been a hand wash car wash for 16 years. It is getting harder because labor is getting more expensive and it is hard to find employees that will do that job. All my competition is hand wash. I wanted to add rocker brushes for now to clean the spots my employees miss and which are most noticeable when customers see their vehicle come out of the tunnel. I slowly want to introduce customers to the whole automatic equipment. Rocker brushes do not looks super aggressive I believe to a customer. Once we do install them I want to see if it helps with the cleaning process and see if I hear any complaints about it. If it all works out and customers do not mind it. I want to slowly add more equipment until I can eliminate the hand wash procedure.
Thank you for the questions you asked. Please let me know your thoughts. It all helps
6.