Friday 8 May 2015

Abrasive Polishes and Pad Performance



Diminishing Abrasives Technology

A non-linear abrasive that require kinetic friction and applied pressure, while the majority of polishes on the market use a form of diminishing (non- linear) abrasive, which you polish until it turns translucent; when a polish "flashes" from a liquid paste to a light semi-dry haze, much like a coating of Vaseline®, proceed until it looks like a clear oil and then stop; the diminishing polish has then broken down and is ready for removal.
Commonly used abrasive, aluminium oxide are banded together (abrasive clusters). Kinetic friction separates them and continues to break them down into smaller segments, known as the primary abrasive. Further application of kinetic energy will break down the abrasives (diminishing) and therefore go from removing paint defects to polishing the paint, which produces the shine. If you don't break them down sufficiently, you are just grinding those abrasive particles into your paint, without polishing it, which can leave behind marring and other paint surface imperfections.

It is important to know when a polish has broken down because if you take it too far you will re-introduce surface marring. During the polishing process, trace amounts of paint and / or oxidation is removed; this can cause the debris and the polish to “clump” together. This can cause a haze to the paint surface, a wipe-down or a paint cleaning product will eliminate this.
When the polish is starting to break down properly you should have a clear surface (somewhat like Vaseline®) keep polishing until the polish becomes clear, like thin clear oil, but still barely visible on the pant surface and then stop as the abrasives are fully broken down. However not allowing the abrasives to break down sufficiently would be tantamount to rubbing sand paper across the paint, causing fine surface scratches

Pros - Menzerna diminishing abrasive polishes are formulated with a long lasting lubricant. The abrasives break down before the lubricating oils dry out, thereby giving polish a longer working time and producing less abrasive dust and avoiding dry buffing.

Cons - Menzerna lubrication oils can be really resistant to removal; it may take 2-3 IPA wipe-downs.

Non- Diminishing Abrasives Technology 
A linear abrasive that require time and pressure - unlike diminishing abrasives, which require friction to enable the abrasives to 'break-down to obtain the best possible finish (and avoid holograms) non-diminishing abrasives react very differently. It will be as abrasive as you want it to be, time and pressure applied (linear abrasive) being its working criteria. By varying pad selection, machine speed and pressure, you can select the amount of abrasive cut required.

Block wet sanding (finishing paper and a sanding block) is the most effective tool for paint defect removal because of its linear process you abrade the paint surface flat until the defects are removed.  Non- diminishing abrasives, a flat foam pad and a rigid backing plate are very similar in application.  

The other similarity between using a non-diminishing abrasive polish and block wet-sanding with finishing paper; the cleaner the media, the more consistent the polishing will be.

It the polishing media becomes saturated, they lose their abrasive abilities. A linear abrasive eliminates the ‘abrasive cycle’ as you have a constant and consistent abrasive medium, the longer you work the abrasive the more surface defects are removed.

Linear abrasive polishes / compounds provides a constant cutting abrasive, as the abrasives  remains uniform in size throughout the polishing process, so you need to check the surface often. They should be used with a semi-rigid backing plate and a cutting foam or wool pad until the defects are removed (1200 – 1500 RPM) but do not allow the polish too completely dry (as this will also produce holograms) and ensure that pad surface is cleaned by removing paint / polish debris regularly This type of compound / polish process usually requires subsequent polishing step(s) to further refine the finish and to produce a shine

Cons - the lubricating oils dry out, thereby providing a shorter working time, producing more abrasive dust and the possibility of dry buffing

Meguiar’s Super Micro Abrasive Technology (SMAT) - that is used in these polishes (M105 Ultra Cut Compound 1200< grit CAS 10/10 and M205 Ultra Finishing Polish CAS4/10) utilizes non-diminishing abrasives. Using a compound with a random orbital polisher requires a very different technique, pressure, pad size and selection, pad priming (with the compound) etc. The product used is a non-diminishing, heavy cut compound, applied with a 6 – inch LC CCS Orange Light Cutting or Yellow Cutting flat foam pads with a semi-rigid Velcro® backing plate (to ensure maximum abrasive used over minimum area) and ensure that pad is clean by removing paint / polish debris regularly or replace

Like all linear abrasive compounds or polishes, they require a correctly primed pad, to ensure sufficient product, the use of applied pressure to ensure abrasive contact with the paint surface, this ensures constant surface contact. Linear abrasives require that you work the product until you achieve the desired finish.

Prime the pad by semi-saturating (80%) the pad with M105 and spread the abrasives uniformly. Keeping the pad flat while applying a constant / consistent pressure; thus ensuring constant paint / polish contact, when the initial polish has been expended replace with 5-6 small sized dots. Keep the pad flat (like you would with a sanding block) while applying constant pressure, the oils in the polish provide the lubrication (like the water does in wet-sanding).Do not allow the pad to “load-up”

Pad grit number, amount of pressure applied and time will all affect the amount of abrasion achieved. If the initial process doesn’t provide the desired finish, increase the aggressiveness of the process; i.e. use a longer working time, increased pressure, increases the cut of the polishing pad. A properly primed cutting pad will eliminate most surface scratches and FM4005 will polish (burnish) the finish

Pad Dependency

Any abrasive polish and pad combination is only as fine as its coarsest component. All abrasive polishes are ‘foam pad and applied pressure dependant’ as far as their paint correction abilities are concerned. Any abrasive / pad combination is reliant upon its most abrasive component.

Foam Pad Design

a)             Non-reticulated [:foam membranes are completely sealed to prevent fluid absorption or air penetration]  (closed-cell) which means less product absorption, and less air flow, reticulated foam are relatively less abrasive and less dense than polymerized foam; due to this density the polish provides the abrasive ability as opposed to the foams composition (use when thoroughly dry as they tend to retain water) with polymerized foam your polish stays wetter for  longer, which extends the products work time This pad design is relatively firm so that none of the machines action (rotational or orbital) is lost, as is the case with soft foams. Due to their lack of airflow the foam doesn’t drain that well they are harder to clean, and take longer to dry

b)             Reticulated [: foam which is a linked network or matrix of small squares or shapes] its composition varies with pore size. Their open-cell construction allows for fluids to permeate the pad to a greater degree than closed-cell materials, such as non- reticulated foam and their lower tensile strength allows them to conform to contours more easily. Reticulated foam, which is a less dense than polymerized foam, therefore your polish provides the abrasive ability as opposed to the foam. Porosity is typically 95%, but can be as high as 98%, typically resistance to compression is decreased while tensile properties like elongation and resistance to tearing are increased. This pad design is relatively soft so that some of the machines action (rotational or orbital) is lost

·         Compression / Rebound - compression load deflection is the measurement of how long the foam takes to regain shape after under certain pressure, foam pads should be compressed to no more than approx. 50% of its thickness

·         Tensile strength – the strength of a material refers to the material's ability to resist an applied force

·         Density - provides a protective cushion allowing foam compression to maintain constant surface pressure and it also lessens machine vibration. It also affects the amount of polish the pad will hold; foams that hold a high volume of product allows the polish to do the cutting, as opposed to the abrasiveness of the foam.

·         Velocity - pad velocity is substantially increased with a larger diameter pad, increased velocity will increase abrasive capability at the outer edge of the pad.

Foam Pad Thickness

Standard foam pads - 1.25 inch pad thickness was set as an industry standard because it prevented solvent residues and provided insulation from friction heat from reaching the backing plate, either of which could compromise the Velcro® (delaminate from the backing material). They have a rounded outer edge for easy transitions over seams and edges, and there is also a safety margin between the edge of the baking material and the foam with a ‘standard’ foam pad.

This foam density provides a protective cushion allowing foam compression to maintain constant surface pressure and it also lessens machine vibration.

OEM-style 7/8-inch foam pads - due to the reduced foam thickness tilting a 7/8 inch pad will change the polishing pressure on the surface.
These foam pads are flat cut on the top edge, as opposed to a standard 1.25-inch, which have a rounded outer edge for easy transitions over seams and edges and the backing material is cut back 3/8 of an inch around the perimeter of the pad to ensure a safety margin.
On the 7/8-ich foam pads the backing material extends to the edge of the pad where it could scratch the paint when working in close corners or around mirrors and wings. OEM-Style pads are designed for high volume pad users where cost is a significant factor

Like all things related to tools, pad thickness comes down to personal preference.

Pores per inch (PPI)

As an example  you could purchase two seemingly similar pads based upon their PPI rating, but one pad may have thicker walls between each pore, be made of softer material, feature a reticulated or non-reticulated foam structure (basically open or closed cell), or simply be a thicker (1.25 or 0.75-inch) foam, which can affect the machine's movements.

Compressible, open cell polyether polyurethane reticulated foam is usually specified by pores per inch (PPI).The greater number of pores per inch generally equates to foam that is softer; and has less abrasive ability, less density, more porosity and easier compression.

There is no recognisable standard for the abrasive abilities of foam, other than a colour assigned; most foam manufacturer’s that supply foam to detailer’s product vendor assign their own colours to donate abrasion. On this basis a PPI rating allows abrasive ability comparisons between different foams

Remember the flatter and more uniform you make the surface, the greater the light reflection .While most enthusiasts understand this principle when applied to polishing, the same is true of finishing. The more uniformly you apply the final wax or sealant, the greater the shine
                  Scale 30 – 100 pores per inch (PPI)

                      Abrasive Cutting Foam (40 PPI)
                      Medium Cutting Foam (50 PPI)
                      Light Cutting Foam (60 PPI)
                      Finishing Foam (70 PPI)
                      Fine Application (80 PPI)
                      Ultra-Fine Finishing (100 PPI)

Note: Harder pads (low PPI) create more surface resistance and consequently more kinetic energy (surface heat)

The thicker consistency products (i.e. a hard wax) seem to work best with a more porous pad; a very tight pad used with these types of products seems to load up and clog the pad, which in a turn leads to product clumping. When applying light consistency products (i.e. liquid polymer) a more porous pad will absorb and waste product

Note: Many foam pad mfg. do not use the PPI identification system

Equivalent Abrasive Rating

The grit rating on an abrasive or polishing pad is an indication that a product  is designed remove the surface scratches left by finishing paper (i.e. 2500 grit scratches are removed by a 2500 grit rated polish)  it doesn't mean that it is a 2500 grit level abrasive.
                      The coarser the abrasive, the faster the cut
                      The more aggressive the pad, the faster the cut
                      Wool cuts faster than lamb’s wool, foamed wools are next, then foam.
                      Foam pads generate more friction induced heat than wool pads

Pad Dependency

Any abrasive polish and pad combination is only as fine as its coarsest component. All abrasive polishes are ‘foam pad and applied pressure dependant’ as far as their paint correction abilities are concerned. Any abrasive / pad combination is reliant upon its most abrasive component.

Foam Pad Design

a)             Non-reticulated [:foam membranes are completely sealed to prevent fluid absorption or air penetration]  (closed-cell) which means less product absorption, and less air flow, reticulated foam are relatively less abrasive and less dense than polymerized foam; due to this density the polish provides the abrasive ability as opposed to the foams composition (use when thoroughly dry as they tend to retain water) with polymerized foam your polish stays wetter for  longer, which extends the products work time This pad design is relatively firm so that none of the machines action (rotational or orbital) is lost, as is the case with soft foams. Due to their lack of airflow the foam doesn’t drain that well they are harder to clean, and take longer to dry

b)             Reticulated [: foam which is a linked network or matrix of small squares or shapes] its composition varies with pore size. Their open-cell construction allows for fluids to permeate the pad to a greater degree than closed-cell materials, such as non- reticulated foam and their lower tensile strength allows them to conform to contours more easily. Reticulated foam, which is a less dense than polymerized foam, therefore your polish provides the abrasive ability as opposed to the foam. Porosity is typically 95%, but can be as high as 98%, typically resistance to compression is decreased while tensile properties like elongation and resistance to tearing are increased. This pad design is relatively soft so that some of the machines action (rotational or orbital) is lost

·         Compression / Rebound - compression load deflection is the measurement of how long the foam takes to regain shape after under certain pressure, foam pads should be compressed to no more than approx. 50% of its thickness

·         Tensile strength – the strength of a material refers to the material's ability to resist an applied force

·         Density - provides a protective cushion allowing foam compression to maintain constant surface pressure and it also lessens machine vibration. It also affects the amount of polish the pad will hold; foams that hold a high volume of product allows the polish to do the cutting, as opposed to the abrasiveness of the foam.

·         Velocity - pad velocity is substantially increased with a larger diameter pad, increased velocity will increase abrasive capability at the outer edge of the pad.

Foam Pad Thickness

Standard foam pads - 1.25 inch pad thickness was set as an industry standard because it prevented solvent residues and provided insulation from friction heat from reaching the backing plate, either of which could compromise the Velcro® (delaminate from the backing material). They have a rounded outer edge for easy transitions over seams and edges, and there is also a safety margin between the edge of the baking material and the foam with a ‘standard’ foam pad.
This foam density provides a protective cushion allowing foam compression to maintain constant surface pressure and it also lessens machine vibration.

OEM-style 7/8-inch foam pads - due to the reduced foam thickness tilting a 7/8 inch pad will change the polishing pressure on the surface.

These foam pads are flat cut on the top edge, as opposed to a standard 1.25-inch, which have a rounded outer edge for easy transitions over seams and edges and the backing material is cut back 3/8 of an inch around the perimeter of the pad to ensure a safety margin.
On the 7/8-ich foam pads the backing material extends to the edge of the pad where it could scratch the paint when working in close corners or around mirrors and wings. OEM-Style pads are designed for high volume pad users where cost is a significant factor
Like all things related to tools, pad thickness comes down to personal preference.

Pores per inch (PPI)

As an example  you could purchase two seemingly similar pads based upon their PPI rating, but one pad may have thicker walls between each pore, be made of softer material, feature a reticulated or non-reticulated foam structure (basically open or closed cell), or simply be a thicker (1.25 or 0.75-inch) foam, which can affect the machine's movements.

Compressible, open cell polyether polyurethane reticulated foam is usually specified by pores per inch (PPI).The greater number of pores per inch generally equates to foam that is softer; and has less abrasive ability, less density, more porosity and easier compression.
There is no recognisable standard for the abrasive abilities of foam, other than a colour assigned; most foam manufacturer’s that supply foam to detailer’s product vendor assign their own colours to donate abrasion. On this basis a PPI rating allows abrasive ability comparisons between different foams

Remember the flatter and more uniform you make the surface, the greater the light reflection .While most enthusiasts understand this principle when applied to polishing, the same is true of finishing. The more uniformly you apply the final wax or sealant, the greater the shine
                  Scale 30 – 100 pores per inch (PPI)

                      Abrasive Cutting Foam (40 PPI)
                      Medium Cutting Foam (50 PPI)
                      Light Cutting Foam (60 PPI)
                      Finishing Foam (70 PPI)
                      Fine Application (80 PPI)
                      Ultra-Fine Finishing (100 PPI)

Note: Stiffer (harder) pads (low PPI) create more surface resistance and consequently more kinetic energy (surface heat)

The thicker consistency products (i.e. a hard wax) seem to work best with a more porous pad; a very tight pad used with these types of products seems to load up and clog the pad, which in a turn leads to product clumping. When applying light consistency products (i.e. liquid polymer) a more porous pad will absorb and waste product

Note: Many foam pad mfg. do not use the PPI identification system

Equivalent Abrasive Rating

The grit rating on an abrasive or polishing pad is an indication that a product  is designed remove the surface scratches left by finishing paper (i.e. 2500 grit scratches are removed by a 2500 grit rated polish)  it doesn't mean that it is a 2500 grit level abrasive.

                      The coarser the abrasive, the faster the cut

                      The more aggressive the pad, the faster the cut

                      Wool cuts faster than lamb’s wool, foamed wools are next, then foam.

                      Foam pads generate more friction induced heat than wool pads

I would like to think that these articles become an asset to anyone who is new to detailing and to professionals alike, as well as industry experts who seek to advance their knowledge.

I hope the above article was 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 this article as it helps other detailers further their knowledge. Questions and/ or constructive comments are always appreciated.


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