Overview:

The purpose of using a foam pre-wash, is to help soften any heavily bonded dirt, flies etc and also suspend loose dirt, acting as a carrier to transport it away from your vehicle when you rinse it off. Most pre-wash foams are also ph neutral, so won't strip off any protection, but it is of great importance to check before purchasing. Some "Snow Foam" solutions, actually contain alkali's, similar to that found in Trafic Film Removers (TFR), and these will strip away any protection you have on the car.

Sometimes you could use a TFR, if the car is very heavily soiled and you were planning on doing a full detail with new protection etc. They are chemically stronger than pre-wash foams, so just look out for which one you're using or which one you need to use for a specific job.


The process:

You can start with either a dry or a wet car, it makes little difference I have found. If heavily soiled I tend to spray the foam on dry, as it does seem to soften the hard bits better, I would guess this is because the water on the car if you rinsed first, dilutes the foam...




From the point you fully cover the car, you want the foam to go on quite thick and cover the entire car. The picture you see was taken after it had been on the car for around 5mins, hence why it was starting to slide off (as seen on the floor). Leaving the foam to dwell for ~5mins is about the optimum time for it to work. During this period, you can take a small soft bristled brush and agitate around the window trims and all other details on the car to help remove excess dirt from the areas which collect it most.




Once 5mins or so has passed, you can then begin rinsing the foam off. The foam will have collected the loose dirt (if you look at the foam on the ground it's likely to show such dirt), so be careful when rinsing, and methodically work your way from top to bottom..




That's the pre-wash complete and the car will be wet from just rinsing the foam off. From this point, proceed with your wash phase, as provided in this guide.

This should yield fantastic results, and takes car cleaning just one step further than the guy next door











Recommended list of pre-wash foams:

Stjärnagloss Red Snö
Valet-Pro PH Neutral Snow Foam
Meguiar's Hyper Wash

And a good quality TFR if required:
Autoglym TFR Multiwash


Hope this helps.

Matt.