Although there are still some vehicles that have a single stage paint system (namely Black, White and Red) To confirm that you have single stage paint wipe an inconspicuous area using a mild solvent cleaner you'll see the vehicles paint colour on the cloth.
Until proximally 1970, most cars were painted with solid colour paint as the only top coat layer in a 1-coat – 1-bake system. While initially these coatings were based on alkyd resins and were not very durable, later they came to be based on thermoplastic acrylic enamels, which had slightly better outdoor durability. At the same time, aluminium pigments were used to give a metallic effect. The durability was not sufficient, which then led to the introduction of base coat–clear coat as 2-coat– 1-bake systems.
The differences between a single stage paint system (base and a colour coat) and a urethane clear coat (base, colour and clear coat) finish is that the single stage paint is generally ‘softer’ and therefore easier to polish (this is due to the colour pigment used (i.e. White is very hard (Mohs - 7/10) - Black is softer (Mohs - 2/10) single-stage catalyzed urethane is harder than single-stage lacquer.
You’ll notice that the foam pad will pick up single stage paint colour i.e. on a black vehicle the foam pad will turn black, this is normal; it doesn’t mean you are removing all the paint. Using products that contain oils to provide a gloss is highly recommended
Some manufactures still use a single stage paint systems, especially on red, white and black vehicles. Avoid (unless absolutely necessary) abrasive compounds and / or foam pads (use a Black (Finesse) pad for product application) use a chemical cleaner whenever possible (Zanio Fusion Paint Cleaner or Klasse All-In-One) for surface polishing try the Optimum Hyper range of polishes
Single stage is usually less dense i.e. ‘soft paint’ and therefore easier to correct than clear coat, as a general rule use a more aggressive pad before moving up the scale in an abrasive polish IMO single stage paint has a richer gloss than a clear coat finish
When you use an abrasive product (polish) on a vehicle with single stage paint, you will notice paint transfer on your pads as they tend to oxidize more than clear coat systems so be prepared to clean and/or replace pads often; as a general rule use a more aggressive pad before moving up the scale to a an abrasive polish..
Apply an oil rich product to stabilize the paints binder system (3M Imperial Hand Glaze) apply a thick coat and allow to dwell for 12-24 hours before buffing, repeat as necessary until surface has an ‘oily’ sheen.
Single stage paint stains very easily, remove with a 1:1 distilled white vinegar/ distilled water solution, if this non-abrasive solution doesn't remove them try a mild abrasive polish
The Optimum Hyper range of polishes, Menzerna Intensive Polish or Meguiar's M80, with its diminishing abrasives work very well on single stage paint, removing moderate defects and nicely refining the finish, the polishing oils will restore gloss and depth. Start with Lake County (LC) Orange (light) cutting foam you may also want to try an LC Green polishing foam pad.
For full richness and depth of colour and a richer look you cannot beat a single stage finish.
I hope these TOGWT Detailing Wiki articles will become an asset to anyone who is new to detailing and to the professionals; enthusiast detailer’s and industry experts who seek to advance their knowledge of detailing entry level enthusiast, but to professionals and industry experts as well.