By Christopher Brown of OCDCarCare.com
Automotove Paint Swelling from paint correction (a.k.a. ‘buffing’ or ‘paint polishing’) is a major source in frustration in the auto detailing industry. Unfortunately, paint swelling issues are gaining frequency as automotive paint layers have become thinner over time.
No detailer enjoys redoing a partial or entire paint correction job. Especially when returning to a vehicle to find defects, which appeared to be removed, are still there; hours or days later.
This gut wrenching condition occurs when paint heats up and expands or ‘swells.’ Some paint systems absorb enough heat to enlarge (or swell) their structure enough so the swelling can temporarily hide defects during the paint correction process. However, the problem caused by automotive paint swelling isn’t noticed immediately, its delayed.
The effects of paint swelling during paint correction only appears after the paint fully cools and stabilizes to its normal state— and BOOM some or many of the original defects are visible once again.
In a previous article, OCDCarCare explained how extreme paint correction processes can generate enough heat to potentially cause paint swelling issues with automotive paint. That article focused on the in-depth explanation of heat and swelling issues and the primary causes of automotive paint swell.
This article is intended to provide information and methods for reducing and or managing heat produced during all automotive paint correction (a.k.a.polishing or buffing) processes.
These concepts apply to frequent and typical situations which auto detailers face on a regular basis. Awareness and use of these concepts and procedures can greatly limit heat generation during paint correction, thereby reducing the overal amount of automotive paint swelling.
#1 Know and Understand the Various Substrates of a Vehicle
The material something is made from is called the substrate. In this context, automotive panels and their material composition are the focus.
Understanding how a substrate material dissipates (releases) heat is an important aspect of automotive paint polishing.
In general, metals dissipate heat well. This means it requires more heat to get them warm to hot, and when hot, they cool off rather quickly.
Substrates such as plastic bumpers, carbon fiber panels, fiberglass, or composite plastics behave the opposite of metal. They have very little mass and their material composition does allow for efficient heat dispersion. Therefore they heat up faster and hold heat longer. In fact, some are hyper sensitive to heat, especially when its introduced quickly.
To effectively manage the heat and the swelling of panels during paint correction it is vital to understand:
- The many different substrates which make up a vehicle & their locations
- How those substrates react to heat
If the substrates of a vehicle are unknown, take the time and research the vehicle. A little bit of research can save a LOT of time and frustration to reduce heat when performing paint correction on a vehicle.
In general, if dealing with plastics or non metal surfaces, understand they will hold heat longer. Therefore, if you need to perform heavy polishing, you must allow the panel or subsection, time to cool between processes. This ensures the overall safety and integrity of the paint system, while decreasing the likelihood of a detailing accident, such as burning through paint.
#2 Heavy Compounding: Allow Panels to Cool Between Steps
This strategy works for all vehicle paint systems for all process with multiple steps of polishing. However, it is especially useful for reducing heat on paints requiring multiple compounding process since they are jacked up. And.. Yes, that’s a highly technical term…
This means vehicle surfaces that require a two-step paint correction, or more, to revive the finish back to life.
A two-step paint correction includes:
- A Compounding Step to remove the defects from the surface,
- A Finish Polishing Step to remove the marks created by compounding.
However, some vehicles are so “wrecked,” “beat (up),” “jacked (up),” “hammered”, or “thrashed,” that they need multiple compounding steps.
When multiple compounding steps are necessary, it is better to allow the area or panel to cool from the first compounding step, before moving onto the next.
A simple method to achieve this:
- Perform a compounding step on Panel A
- Move to an adjacent panel– Panel B. Fully compound Panel B before performing a secondary compounding step on Panel A.
IF the panel is large enough, it may be possible to work to another area (other non adjacent side of a roof or hood) will allow the first section to cool off.
This concept also applies to all paint polishing steps. Allow panels or areas to fully cool between any steps to avoid paint swelling.
#3 The Size of a Panel or Working Section Heavily Influences the Rate of Heat Generation
This directly ties into the previous concept and magnifies it.
This size of a object dictates how much heat it can hold.
To demonstrate this, think of heating a standard 10” (~25cm) copper pan with a welding torch. It requires a significant amount time to heat a pan’s surface to 425°F (~218°C) in order to sear a steak.
However, it will take a mere fraction of the time and energy to heat a standard U.S. copper penny to 425°F (~218°C).
Why? Because heat build-up is based on both material composition and the mass of an object.
“How does this relate to heat and paint correction?” you ask.
If a panel is small, it heats up quickly because there is less mass and surface area to disperse heat. Therefore, detailers need to consider the size of a panel before starting paint correction.
If an area is small, it cannot follow the same process of polishing as used for a hood or a roof. The heat builds much quicker on a panel with a small surface area and mass.
Therefore, different processes are necessary on different sized panels. Imagine the amount of heat generate if you were to use the same amount of passes on 1/4 of a jacked up Dodge Ram roof and did that same process on a BMW M3 front fender. The process may only cause the Dodge roof to be slightly warm, however it would cause the M3 fender to become extremely HOT.
#4 Avoid Over Cycling Compounds or Polishes During Paint Correction
A polishing cycle is the amount of time a compound or polish is used (worked) over an area to remove defects during paint correction.
Many correction liquids on the market tout features of “long working time.” Well, the length of a polishing cycle MAJORLY influences the amount of heat generated into a paint system. This is magnified when paired with a long stroke Dual Action Polishers (especially a 21mm) and microfiber pads.
Combine this with the tendency of most detailers to over work (over cycle) correction liquids, and lots of heat is generated—QUICKLY!
They key here is to perform a test spot to find how many passes are actually needed for a particular result on each paint system.
Short Cycle Polishing with Non-Diminishing Abrasive Agglomerate Correction Liquids is the safest, fastest, most efficient and profitable paint correction procedure.
#5 Limit the use of Paint Swelling Solvents when Polishing Paint
Using a Combination of heavy solvents, from a few sources, can quick accelerate the speed and level of a paint swelling. Heavy solvents start swelling automotive paint before any paint correction begins. Use of these solvents can greatly magnify the negative impact of heat on automotive paint systems.
The main concept: avoid solvent heavy as much as possible on paint correction surfaces.
Solvents Types to Avoid or Limit Use as Much as Possible Prior To Paint Correction:
- Solvent Prep Solutions. These strip surfaces of traffic film, old waxes, and sealants, as a first step procedure.
- Heavy Compounds Containing Aggressive solvents for “chemical cut”. These solvents intentionally swell the paint system in order to reach in matrix of the paint to cut deeper.
- IPA (Isopropyl Alcohol) or ‘Panel Wipe’ solvent based solutions to remove left over polishing carrier oils.
There are a few options here:
(A) Limit the use of “panel wipes” as much as possible. Instead of using after compounding, and then again after polishing—just use after polishing.
(B) Use the lowest quantity of product to get the job done to limit their impact on paint swelling. This lowers the overall amount of solvents potentially absorbed into the paint.
(C) During use, spray them to a towel and then apply to surfaces. Spraying a panel wipe directly to a vehicle’s surface may quickly inject a high amount of heavy solvents into a small area. As a result discoloring, or worse, may occur on sensitive paint systems or substrates.
Combine These Five Concepts To Reduce Heat & Swelling From Paint Correction
There are many other factors, outside these five concepts, that contribute to automotive paint swelling.However, the concepts listed here are universal and affect any and all detailing paint correction processes.
For the majority of auto detailing paint polishing, if these five concepts are fully understood and applied then excessive heat, and high levels of swelling from paint correction, are significantly reduced.
“ALWAYS Keep Learning to Strengthen Your Passion & Your Business.”
© Christopher Brown – OCDCarCare Los Angeles
- Vehicle Water Spots Explained: Formation, Removal, & Prevention - 28 August, 2023
- Automotive Paint Thickness Gauge (PTG): Detailing User Guide - 2 September, 2022
- 5 Thin Automotive Paint Layers Explained For Detailing - 10 July, 2022