Continuing our series of blogs focusing on frequently asked questions, we’re going to present two e-mail enquiries concerning the wash process; specifically about the role of pre-wash foaming and shampoo choice. We receive a lot of enquiries about these topics, so hopefully what follows will be useful. However, as always, if you have any remaining questions please feel free to fire away below and we’ll do our best to help.
1. “I’ve seen foam lances on your site that attach to pressure washers: are these safe to use on paint and glass? Does using a foam lance mean I don’t have to wash the car with a mitt and buckets?”
The role of pre-wash foaming is a stage of detailing that, if not quite vital, is extremely important. We always rinse the car thoroughly before foaming using a pressure washer, if available, to remove as much loose dirt and grime as possible.
We have seen some detailers argue that pre-wash foams should be applied to a dry car, the theory being that on a wet car the foam will slide off too quickly. While there is some logic to this, if you foam a dry car, the foam’s not getting a chance to work on the more deeply layered dirt bonded closest to the paint. Hence why we blast off loose dirt first, working top-down, and then let the foam go to work on anything remaining.
Our regular pre-wash product of choice is Meguiar’s Hyper Wash; it cleans effectively, doesn’t strip paint protection and has a dilution ratio of 400:1 (water/product). Many other foam products have dilution ratios as low as 25:1, so whilst they may be cheaper to buy, in the long term they work out more expensive. Furthermore, some are quite aggressive; whilst they may clean well, their excess strength can strip wax or sealant protection and, in some cases, stain plastic and chrome trims.
In use, an appropriately diluted Hyper Wash solution should be applied to the car, again working top down, and allowed to dwell on exterior surfaces for 5-10 minutes. It’s ideal to use on wheels, tyres, glass, under the arches and on plastic trims, so long as it’s not allowed to dry fully onto any surfaces. In hot weather, or if working in direct sunlight, rinse the foam off before it dries out completely.
Pre-wash foaming isn’t designed to replace a proper hand-wash, but will remove a good proportion of dirt and grime prior to starting the hand-wash process. This is the critical benefit that pre-wash foaming offers; the less dirt there is on the surface when you start hand washing, the lower the risk of marring or swirling the paint.
Through the winter months, when the car is subjected to increased contamination in the form of road salt, general grime and traffic film and tar, pre-wash foaming becomes even more important. This is because increased contamination leads to a higher likelihood of marring or swirling of the paint when it comes to washing off all this grime.
Foam will soften and partially remove road salt, making the hand-wash process both faster and safer. Foaming and very careful washing, taking care to change the water in the rinse bucket regularly, will go a long way to keeping your car’s paintwork defect-free. My previous blog about Safe Washing covers this in detail.
You can perform pre-wash foaming with stronger products to strip more dirt and grime, but only at the expense of existing wax or sealant protection. Meguiar’s All Purpose Cleaner is a powerful cleaning product, as is R222 Total Auto Wash, and both of these products excel in this role. However, both will, to a degree, strip existing protection on the car – bear this in mind from the outset.
Foaming with stronger cleaning products is usually safe for all exterior surfaces (with the exception of convertible tops) but care should be taken not to work in direct sunlight or let the foam dry out – if in doubt, read the instructions carefully first. In summary, although foam lances are a valuable part of the detailing process and certainly do lessen the risk of inflicting paint defects, they aren’t a replacement for careful hand washing.
John @ PB
2. “I’ve always used whatever shampoo is cheapest from my local motor store, or, more often now, from the supermarket. Is there really that much difference in performance between them and the shampoos you sell? The price difference keeps me buying the cheaper ones.”
Shampoo choice has a strong effect on the overall ease and safety of the wash process, and the durability of sealant or wax protection on the car.
Many cheaper shampoos, often found on the high street, are really quite strong; they’re designed to strip dirt and grime quickly. The problem is, they can often strip paint protection, undoing all your hard work applying waxes or sealants. Furthermore, they can also streak badly and, in some extreme cases, stain plastic trims slightly.
When testing a shampoo, we look at a number of key factors. Slickness is one; when washing, the shampoo should help the wash mitt glide easily across exterior surfaces. In the overall scheme of things, this is perhaps the most important point. A properly lubricated shampoo greatly lessens the risk of causing marring and swirling; if a shampoo doesn’t feel very slick, it’s probably not worth using.
Overall cleaning power is also an important point, as is the ease with which the shampoo rinses off. Shampoos that rinse poorly typically streak, particularly when used in warmer conditions. This is often most evident on black or darker coloured cars. We monitor the longer term effects of shampoo usage on the durability of paint protection too; as you would expect, stronger shampoos typically strip paint protection more quickly than their weaker counterparts.
The amount of suds produced by a shampoo is often considered to be an important point. However, in our experience this is not so. Some shampoos that generate lots of suds are actually poorly lubricated, and vice versa. We tend to always look for proper lubrication first, as this is more critical. However, if you prefer lots of suds, use a jet of water from your hose or pressure washer to agitate the water in your suds bucket.
The ph value of shampoos seems to crop up online regularly, with some detailers insisting that shampoos must be ph neutral (7) if the stripping of paint protection is to be avoided. This is untrue; one shampoo we stock (Nanolex Reactivating Shampoo) has a ph value of 5 (making it mildly acidic), yet it doesn’t strip waxes or sealants and, in fact, actively adds fresh protection as it washes. In most cases, the type of detergent used is a more critical point, so look for a shampoo that, in light of real world testing, has been proven not to strip waxes or sealants.
Another factor to consider, and this one is completely objective, is dilution ratio or, more accurately, cost per wash. Some shampoos appear to be very expensive, but when their high concentration and dilution ratio are factored in, turn out to offer excellent value for money. It might be worth checking the dilution ratio of your current shampoo and working out the cost per wash; if it’s a cheap affair bought on the high street or in the supermarket you might be in for a surprise!
It can sometimes be beneficial to select your shampoo to match the protection on your car (e.g. using Meguiar’s Ultimate Wash & Wax to maintain finishes protected with Meguiar’s synthetic waxes), but there are many shampoos that will happily work in all cases, no matter what protection has been used on the car. If you’re in any doubt as to which shampoo will give you the best results, please feel free to email or call for one to one advice.
John @ PB