Newly Painted Surface

[darthkir]

Hi,

I am going to send my 2 week-old car to get the rear bumper repainted, thank to this kid who scratched a quarter of the bumper with the side of his car.

My question is, after the paint job, how long do I need to wait before I can properly wash or wax the bumper again?

Thanks!

[TOGWT]

Re: Newly Painted Surface

Washing should be OK (use a concentrate that doesn't contain wax)

Polishing or Waxing Fresh Paint (This refers to repainted finishes not new vehicle paint)

The most often asked question and a subject that results in a great deal of confusion regarding polishing or waxing fresh paint. The majority (approx 90%) of refinish paint supplied by BASF DuPont, PPG and Sherwin Williams is duel component polyurethane; one component is polyisocyanate and the second is a polyol (acrylic or polyester polyol). Water or solvent-based paints (which constitutes the majority of what is still being used) once the two components react they form a polymer chain that it is not affected by most solvents (with the exception of paint removers or so-called paint thinners, such as Dichloromethane or methylene chloride).

While newly refinished paint is about 90% cured within 24 hours, although it does take up to 30 days for it to fully crosslink. Automotive paint is classified as a semi-permeable membrane, some chemicals penetrate easily(solvents) During this period, using waxes or sealants that use a solvent as their carrier system should not be used since the solvents permeate the paint and soften it and if the wax or sealant contains abrasives, it can cause micro marring on the softened paint. The best products to use during this period are therefore water based systems that are both solvent and abrasive-free.

Most paint shops use 10-20% more isocyanate component (hardener) than the polyol component. The reaction between these two (isocyanate and alcohol) is fairly rapid and that accounts for the 90% curing rate of the refinish paint within 24 hours. That leaves about 10% un-reacted isocyanate, some of these isocyanate groups slowly react with moisture (hence the term moisture cure) and form amine groups (releasing CO2). The newly formed amine groups rapidly react with isocyanate groups to form urea or polyurea, which is much harder than polyurethane adding solvents to the paint, hindering this reaction, while water-based products can help the (moisture) curing process.

I would suggest waiting for approximately ten to fifteen days before any product application, which should be more than sufficient time to enable paint off gassing and aerobic curing.

If it just came from a paint / body shop fresh paint shouldn’t need polishing, but it won’t necessarily damage the finish. Although using a high sped rotary, an abrasive compound, wool or a dense foam pad and heavy pressure; as this combination can cause paint to ‘twist’; this occurs when dynamic friction (heat) is created along with heavily applied pressure combine to alter the bond between the paint and its substrate, which can cause the paint film (or paint containing flex agent) to ‘twist’ and delaminate.

Applied after polishing, a glaze is the masking ‘make-up’ that hides flaws and gives paint the sheen it had in the showroom. The common ingredients in a’ fresh paint safe’ glaze are: water, glycerine (to produce a high shine) amino-functional mineral oils and mild abrasive Kaolin (China clay) to burnish the surface and produce a gloss, they exclude silicone and wax, some polymers are also formulated as ‘fresh paint safe’ for the same reasons

The application of a specific ‘fresh paint safe’ or polymer type product, Zanio Z Polishes (exclude the use of either Z1 or ZFX™) Optimum Car Wax is water-based and is safe on fresh paint, or use Presta Fast Wax. Allow an ‘initial gas off’ (evaporate) /cure aerobic process of 7 days before application

These products are completely safe for any fresh paint system as they allow the solvents in a water-based paint to outgas / aerobic cure process and provide some protection for any type of paint surface. After thirty days (30) the paint surface can be protected with a regular polymer sealant and/or Carnauba wax.

If in doubt ask the paint / body shop so as not to void any guarantee and / or paint warranty

An extract from one of a series of unbiased “Detailing Technical Papers” © TOGWT ™ Ltd Copyright 2002-2009, all rights reserved.

[darthkir]

Re: Newly Painted Surface

Wow, great explaination... thanks!

So Im safe to use my NXT car wash on it right?