Source: YouTube
A cheap hand wash or automatic machine wash can both be bad for your paint. I am aware of the value the tunnel washes in particular provide for the general population. I am including those frequent or occasional users of the automatic wash that complain about the lack of thoroughness in cleaning. For people that are not that particular about their car, this content is not for you. I have to imagine the majority of people who are on Detailed Image have some desire to see their paint look better.
Swirls, scratch problems, and potential trim/molding damage are an issue but there is more. Chemical staining is a significant problem. This is particularly the case with touchless washes but can involve washes with brushes as well. Even with protection products ranging from wax, sealants, to coatings there are consequences beyond the damage chemicals can cause. Although especially coatings can protect your paint from this damage, it will take an unnecessary level of degradation and (directly and indirectly) drop in some of its performative qualities.
The Misconception That Any Hand Wash is Automatically Better
Just because someone offers to or a business offers to wash your car by hand, does not mean you are safe from swirls and scratches. In fact often times it is a worse alternative than the brushes from a tunnel wash. The following is a rarely understood concept by the mainstream public but known to detailing professionals who are often labeled ‘high-end’. Businesses that fall under the category of your local car wash or detailers who offer comparably cheap washes and cheap details, do more damage to your paint than the machine washes.
I understand there are no hard and fast rules for the general population to spot the cheap wash, although my intuition picks this up immediately. These are a couple of obvious signs to look for. A gas station has signs for their automatic car wash on display or flyers. If someone’s advertising looks remotely like this, that is a bad sign. As painful as it seems to you especially in these times, if the hand wash price is remotely close to what comes from an automatic car wash, that is a red flag. Pricing is usually the most obvious giveaway with how much care someone is going to put into carefully touching your paint. $20 versus $50 versus $100+ are 3 tiers that are typically going to be dramatically different in processes.
There is another issue that most people struggle to accept. Most people can easily choose to do a much better job, in terms of safety, of washing their car. I will even throw in between wash behavior, like touching their car. Even people who tell me they want swirls and even scratches gone from micron thin paint are not immune to this. Imagine a service that often from a business standpoint should cost potentially in the thousands, being desired by a client who rubs on (adding scratches to) the paint they want to look better. I have witnessed this contradiction multiple times.