Polish Methodology (polishes and pad selection)
What polish / pad combination to use - there are far too many variables to answer this question with a viable solution.
There are a multitude of question about polishing and pad / compound that can be answered with something as simple as ‘use a test panel’
Diagnosis is the key; not guesswork; examine the vehicles bodywork, a ‘bag-test will ascertain the need for paint surface decontamination and a 3M Sun Gun or a Brinkman light will help you find any evidence of surface blemishes i.e. swirl marks and scratches.
The most important first step in the process of paint surface detailing is diagnosing the paint surface; density of clear coat (hard or soft) or single stage paint, surface condition; ascertain the severity of the surface blemishes with an inspection light and the paint thickness available. The paintwork should be evaluated with a paint thickness gauge to see what thickness of clear coat remains before you decide how much paint renovation can be safely carried or wither paint preservation would be the appropriate option, before you proceed, measuring with a paint thickness gauge will dictate the choice and abrasiveness of polish / compound for correction or renovation level required or indeed possible
However there is a methodology that can be used to identify what will work to meet your detailing goals for a particular vehicle
Test Panel Area
The differing density (hardness) of paints react differently to correction, so before beginning to polish measure the paint thickness (PTG) panel by pane to ensure that you do not select an aggressive polish that will reduce too much clear coat.
Then select a ‘typical’ panel; one that represents the type of defects that you want to remove and the finish level required. Select an area of 18 x 18-inches and tape it off with painter’s tape, as this is an optimal working section to perform a product test spot; this will help establish a polish – pad combination that will produce the best possible finish that corresponds to your detailing goals for the vehicle.
Pay attention to how the paint is responding to your inputs. Stop and evaluate your progress, once this is established; repeat the process over the entire paint surface, adjusting abrasiveness for any low paint thickness.
There may be some areas that have deeper scratches, which will necessitate a more abrasive polish. This is known a ‘spot-correction’. Once this area(s) are completed revert to the original polish / pad combination, there is no need to remove any more clear coat than is necessary
Experience will teach you how your polish/pad combination ‘feels’ as it goes through the various stages; i.e. cutting, to polishing stage and finishing stages, just when the polish lubrication has dried up (this is usually when a polish starts to produce ‘dust’), this is where you stop, wipe off the polished area, inspect the paint surface and either clean the pad, apply more polish or change it for a clean fresh one.
There comes a point when you must judge wither removing a scratch will compromise the clear coat 0.3 Mil > (8 µ) and if so you’ll have to ‘live’ with the imperfection (these can be aesthetically masked by using a Glaze)
Using a medium abrasive polish and a rotary polisher will remove approximately 0. 1 Mil (3µ micron) range 0.08 – 1 Mil (2 – 25µ) from the paint surface (typically 4 passes at 1500-1800 RPM) Common sense needs to be part of the equation also, but there are many variables such as the abrasive grade of the polish or compound and speed and pressure used that may affect the paint removed)
These numbers should be checked with a paint thickness gauge (PTG) There comes a point when you must judge wither removing a scratch will compromise the clear coat and if so you’ll have to ‘live’ with the imperfection.
These numbers are offered as a guide only, as there are too many variables to provide any more than an approximation.
Testing the paint surface
Always follow the rule of starting with the least abrasive combination, i.e. a machine polish and the least aggressive foam or wool pad (working smarter not harder) The most important first step in the process of paint surface detailing is diagnosing the paint surface; density of clear coat (hard or soft) or single stage paint, surface condition; ascertain the severity of the surface blemishes with an inspection light and the paint thickness available.
Measuring with a paint thickness gauge will dictate the choice and abrasiveness of polish / compound for correction or renovation level required or indeed possible. Assess the correction level working through the range of polishes from the lightest abrasive upwards until the desired level of correction is reached. Selecting the correct pad / polish combination for the vehicles paint / defects can take just as long as the paint correction process
When removing defects from the paint surface, consider not only which polish / compound you'll be using, but how you'll be using it. You choice of machine speed, pad construction, pad size and applied pressure will all impact the abrasive abilities of the polishing liquid.
Decide on a one, two or three step polishing routine and select a suitable pad. After testing a section to confirm this method, Select an area of 18 x 18-inches and tape it off with painter’s tape, as this is an optimal working section to perform a product test spot; this will help establish a process that will produce the best possible finish, once this is established repeat the process over the entire paint surface.
Select a ‘typical’ area - (one that represents the type of defects that you want to remove) and starting with the least abrasive polish and / pad combination. If the first test doesn’t produce the finish you’re looking for move to a different spot and try another pad/polish combination. Then proceed until the defects are removed. This is the polish / pad combination you’ll need to use
Always be willing to learn; because the more you learn, the more you’ll realize what you don’t know.
It is said that knowledge is power, with the caveat that it includes access to a reliable information sources. I would like to think that these articles become an asset to anyone who is new to detailing and to professional’s alike, as well as industry experts who seek to advance their knowledge.
I hope the article are informative. By having some understanding of the ‘What’ and ‘Why’ as well as the ‘How’ along with a little science to help you understand how the chemicals we use react, you can achieve the results you desire.
I would appreciate it if you would share these articles as it helps other detailers further their knowledge.
As always if you have questions, I’ll do my best to answer; bear in mind the only stupid questions is the one that was unasked. Questions and/ or constructive comments are always appreciated
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