We just received this question for a DI blog reader, and it’s actually quite a common question. Below is the two part question and my answer to both parts.
Pressure washing before foam lance soak… which order is best and why? Second, if a car has a lot of tree sap on it, what’s the fastest way to get it all off, because the pressure washer just is not doing it?
First part of the question is:
I pre-rinse the car to knock off all the heavy debris on the paint. I then foam lance the car and allow it to dwell. I work on cleaning the wheels, then rise the entire car. I re-foam lance the car and do a two bucket wash, then rise. Why this method? I want to reduce the chance that debris on the paint will marr the paint. I allow the debris to be chemically removed, and the second foaming I remove any remaining with a mechanical means.
Second part of the question is:
Tree sap removal is varied depending upon how long it has been on there. The more “fresh” it is on the paint, the easier it is to remove. Dried sap needs to be taken back into its liquid form, which means using a solvent. If it is pine tree sap, try using turpentine as that is a tree solvent. You can also try Stoners Tarminator or CarPro Tar X, both of which contain solvents safer for clear coated paints.