dave-C2

My black 996 GT3 was inside the garage when the concrete approach apron was replaced. During demolition of the old concrete pad a lot of dust got under the garage doors and covered everything inside with a pretty thick layer of gray dust.

Although he gave me no warning, apparently the guy doing the project had seen the problem before. He suggested blowing as much dust off the car as possible before beginning any water rinsing and washing.

The dust is from the old hard concrete and the junk fill under it; the new stone fill and concrete was handled well and did not cause any problems.

TIA for experienced based recommended cleaning procedure.

Marine Blue

Using compressed air as a starting point makes sense. Start with a more gentle approach angle and keep the nozzle a good distance away until you have removed the heavy dirt. Once the heavy stuff is off you can use a more direct stream of air and bring the nozzle closer (couple of ft away) until the majority of dust is removed. I will let others chime in as far as the wash procedure from here.

LexVan

Agree with this. Even a quick drive might remove most of the dust before a quality wash. As for washing, this would be a good reason to use a Foam Cannon first. Lubricity during the early wash stages are the key. Also, split the car wash into a least two parts, to minimize dust/dirt contamination. Split top bottom, or left-side and right-side. Something like that. Fresh wash water and wash mit for each split. GL.