Wednesday 15 May 2013

Foam Pads, Selection and Use


Foam Pads
Under a microscope, foam pads look like a bee's honeycomb, small uniformly shaped cells. The smaller the cells the more densely the construction (higher PPI), this type of foam pad would be considered less aggressive, thus it would be considered a finishing pad. The opposite effect takes place if the foam cells were larger, or less dense (lower PPI). This construction will cause the foam pad to be more aggressive, as in a compounding pad.

Pads made of high strength reticulated (artificially broken-in) foam. In other words, the cells are open; this allows air to flow through the foam. Chemical compounds and polishes require the right amount of air flow through the foam. Open cell foam is ideal for this process to succeed. Not only is closed cell foam not ideal, but it is structurally weaker.

The features that distinguish quality foam pads; the use of various, engineered polyether polyurethane reticulated foams imported from Europe, that are specifically designed for machine compounding, polishing and buffing Engineered refers to various levels of abrasive ability or grit number rating.

As a result of improved foam manufacturing technologies, foam pads have made great advances in performance and durability. Like their wool counterparts, foam pads must be properly cared for to insure consistent performance. The vast majority of domestically produced foam is designed for air filtration, not machine polishing.

Foams from third world countries that supply low cost foam cannot match the quality, performance and consistency of European specialty foams that are manufactured to ISO 9000 quality standards.

The pads used at the OEM level worldwide (Audi, BMW, Daimler-Chrysler, Ford, GM, Porsche, VW, etc.) including those produced by 3M are all made from European foam (the majority of which is supplied by Reisgies Schaumstoffe, Global Minority Business Network (GMBN) Leverkusen, Germany) In most cases, these foams are substantially more expensive than domestic foams due to currency fluctuations, ocean shipping, and customs duty and import tariffs. 

If you're looking at a modestly priced pad at your local auto parts or department store, it’s highly unlikely that they are made with quality European foam.

Foam pads perform differently from each other on the basis of how they're constructed.  Under a microscope, foam pads look like a bee’s honeycomb, small uniformly shaped cells.  The smaller the cells the more densely the construction, this type of foam pad would be considered less aggressive, thus it would be considered a finishing pad.  The opposite effect takes place if the foam cells were larger, or less dense. 
This construction will cause the foam pad to be more aggressive as in a compounding pad.  There are various grades of foam pads on either side of the aggressive or finishing scale. 

The face of a polishing pad should be designed to efficiently use its surface contact area. If a foam pad has lines, squares, circles, or dimples cut out of (or pressed into) the pad face, less actual surface area is available compared to a flat pad. Usually these foam patterns are designed to increase buffing performance by the slower release of product, operator comfort or ease of use as they decrease the contact area and the pads efficiency

Periodically inspect the face of your foam pads, eventually you will have to replace the pads as they will wear and lose their abrasive ability just like finish paper

A flexible backing plate and a foam pad with a cut-out design can be of benefit when dealing with surface contours and angles as they tend to conform to these shapes better than a plain flat pad, they also tend to transfer less heat. They also provide an extra level of cushioning while polishing curved surfaces, distributes pressure evenly over the contact area of the pad, they are less aggressive than a more rigid backing plate and will help to reduce swirls

When trying to remove deep sanding scratches, especially if they are close to an edge or a seam a stiffer backing plate is advantageous

The most efficient polishing method is a flat pad applied with consistent pressure; this ensures the surface area of the pad is used efficiently, in a similar way to wet-sanding with finishing paper and a sanding block

Lake Country CCS Dual Action Foam Pads

CCS stands for Collapsed Cell Structure. CCS Technology is Lake Country’s innovative pad design that saves product by controlling product release onto the work surface. Dozens of dimples in the foam collect excess polish and reserve it until it is needed on the pad’s face (the area that is in contact with the paint). This design prolongs your working time and reduces product waste, it will hold more water and take longer to dry then comparable open cell foam pads

·         Slows rate of polish absorption – as discussed above, the pads are slow to absorb products and therefore the paint benefits from a longer working time. The same is true of liquid waxes and sealants.

·         Improves operator control – these pockets gradually release polish as needed by the operator. Since these areas are not absorbing polish, they serve as little reservoirs until the excess polish is needed.

·         Prevents pad skipping the pockets reduce surface tension allowing the operator to run pad flat on a working surface. Basically, the pockets break up the smooth surface of the foam to eliminate the sticking and skipping that occurs when two perfectly flat surfaces meet.

·         Creates less heatpockets provide several points where the foam is not completely touching the paint, this reduces friction and therefore heat generated between the pad and the paint.

·         Original equipment (OEM) approved - tests confirm CCS pads out-perform convoluted pad designs

Notes:
1.      It is preferable to polish 2-3 times to restore the paint film surface than to use an unnecessarily abrasive polish / foam combination

2.      Wool pads are not recommended for random orbital machines (Porter Cable 7424, etc) as wool pads nap / fibres works more efficiently with a centrifugal motion Foam cutting pads tend to be much’ stiffer’  than wool fibres and thus will transfer the movement of the machine to the paint surface more efficiently than a comparable wool pad on an orbital polisher

3.      The Flex 3401 is the exception to (1) above as the forced rotation supplies a centrifugal motion to the pad

4.      Natural wool is most aggressive - 50/50 wool/acrylic blends intermediate -  lamb’s wool  the least aggressive

5.      Always use the least aggressive product first, evaluate the surface, then only if necessary `step-up' to a more abrasive product and / or pad.

Pad cross contamination
·         Clean and / or replace pads as often as is necessary; a clean, primed and seasoned pad will enhance the abrasive abilities of the compound / polish and make the process not only more efficient but less time consuming.

·         Do not use the same pad to apply differing products as cross contamination will reduce the effectiveness or completely negate their purpose altogether.

·         If you thoroughly clean pads right after use you shouldn’t have any problems with contamination from different grades of polishes or compounds. However do not use the same pads for different sealants, or use a pad that has applied a sealant as a polishing pad or vice a versa.

·         Some polishes or sealants may be difficult to completely remove product residue. It is good practice to use a new or freshly cleaned pad with each type of car care product.

Identifying Foam Qualities

There are eight factors that rate in foam quality; Density (or rebound), Compression, Sag Factor, Fatigue loss, Hysteresis, Tensile, Elongation and Tear resistance. However it is compression, hysteresis, and tensile strength that have the most to do with the abrasive or cutting ability of a pad.

These factors all play into how much give the pad has under pressure and torque. Density, (not a measurement of compression) has a lot to do with the amount of polish the pad will accept (see also pores per inch (PPI)) a pad that holds a good volume of polish allows the polish to do the cutting job instead of the pad.

Velocity and applied Pressure are also factors that affect a foams abrasive (cutting) ability, all of these factors affect the flexibility of the foam under pressure and torque

The abrasion or cutting ability of a foam pad relative to its composition, the work is approximately distributed, 60% product, 30% foam composition (density, pores per inch (PPI)) and 10% pressure applied and/or speed of rotation or oscillation.

Pad Dependency

All abrasive polishes arefoam 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.

 If we consider the Lake County (LC) White foam (50 PPI) polishing pad as the baseline; any polish used will derive help from the abrasive abilities of the foam. Then consider the LC Blue (70 PPI) finishing pad has no abrasive ability and will contribute nothing to the cutting capability of a polish.

What is derived from this is that a polishes abrasive ability can be ‘fine tuned’ by using different combinations (abrasiveness) of polish and foam (the same thing is true of wool pads) and of course differing the amount of downward pressure (10-15 Lbs is the usual range) applied will also have an effect on the abrasives capability

Different pad / product combinations (least abrasive pad / polish first)

a)      Base pad / product (least abrasive pad / product) if this combination does not provide the desired results, increase the aggressiveness of the technique or product selection.
b)      Step-up 1 - using the same pad with a more abrasive product
c)      Step-up II – use a less abrasive pad and the same product as used in step-up I
d)     Step-up III- using the same pad with a more abrasive product

As can been ascertained from the above the total abrasive ability of a polish / foam pad combination is subject to many variables, the polishes abrasive ability is just the starting point

Factors that increase abrasion ability    Increased speed (Velocity)
·         Increased pressure (Compression)
·         Use smaller pad(Reduced surface Area)
·         Using a slower panel transition speed (Increased surface contact time)  
·         Reduce the working area

The key to the polishing process is to know how the paint will react with each pad / polish combination you consider using. You must know your product and what its capabilities are before using it. This is why a ‘test’ spot is so important. 

The factors that affect the outcome -speed, friction (kinetic energy) applied pressure, foam pad actual surface contact area, pad grit number (abrasive ability) amount of surface lubrication available, the surface area and heat conductivity of material

All pads have a performance cycle, meaning you will get the desired results only to a certain point on that curve. The point of declining performance is typically reached by polish / compound pad being overloaded with product; you should always be able to see the individual cells or texture of the pad, with proper, regular cleaning pad overload can be avoided.

Clean (or replace) you pads frequently: pads are easy to clean; the slotted pad face actually makes it easy to clean. Do not use the same pad to apply differing products as cross contamination will reduce the effectiveness or completely negate their purpose. A new or freshly cleaned pad must be used with each type of car care product.

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

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

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

Transfer of Kinetic Energy

Dependant on pad choice though the downward pressure though the backing of the pad. The denser the backing the more cut and abrasive ability the polish has and vice versa.

Open cell pads have varying cuts, due to the sharper edges being created, this type of pads absorb the lubricate from the polish and leave the abrasives within the open cells; effectively increasing the abrasive ability of the pad. When you add pressure you also reintroduce the lubricant to the abrasives, which results in a higher cut.

Closed cell pads - have very little cut on their own, as the lubricant sits on the surface as well as the abrasives, by adding pressure the denser nature of the foam will deliver a higher cut.

Microfibre pads - work in a similar way to a closed cell pad, foam pads distort, stretch and compress while being worked on a polishing machine. The greater the thickness of the foam between the backing plate and the car surface, you have one surface that stays rigid, being driven by the polishing machine, while the foam acts as somewhat of a shock absorber. The thicker the shock absorber the more kinetic energy will be lost, reducing the abrasion efficiency

Due to their very thin construction every little kinetic energy is lost; most of it being transferred from the machine to the paint surface, making the abrasive work more effectively.

Comparison of Pad Types

Here's a brief guide to help you select the correct product for your needs, all of these pads have a hook and loop fastening system. The Velcro™ on both the pad and backing plate allows you to quickly and easily install and remove the pads listed below:-

Non-Reticulated Pre-polymer with Collapsed Cell Structure (CCS) Technology™ quality foam pads are made from specially engineered European foam, a blend of thermally reticulated polyurethane with a partially closed foam cell structure, created specifically for compounding, polishing and finishing.

This foam allows air to circulate through the pad to reduce heat transfer to the paint surface or product, while maintaining friction; the secret to successful machine polishing is using the correct type and size of foam pad, and the proper machine operating rotational and linear speed.  

Thin firm foam would work more efficiently than a thick pad at transferring the eccentric motion of the orbital offset motion to the paint surface. 

Thick foam allows more downward pressure, and therefore foam compression, which is not necessary with forced rotation, except when negotiating contours. One of the drawbacks when applying downward pressure a forced rotation it tends to ‘self’ steer the machine

Flat pad- provides an even pressure so it will takes more pressure to stop the random orbital buffers motor, so the finish is more even. They also produce a ‘feeling’ for the surface that you can gauge better than the variable contact pads, this style pad is best for medium polishing and finishing work.
Flat foam pads were the original pads before the introduction of Closed Cell Structure foam, although they share the same advanced foam compositions. Flat pads have a slightly different feel compared with closed cell structure foam especially when used with a rotary polisher.

Once mastered, flat pads break down the polish quicker since fresh polish and their lubrication oils are not being constantly re-introduced to the surface; this allows a skilled technician in a high-volume detail shop or paint and body shop to accomplish more in less time. They are very efficient when used with non-diminishing abrasives as they increase the total surface area of the pad, allowing pressure to be uniformly applied.

It also increases the pad's rigidity against the backing plate, which is very similar to block wet sanding (finishing paper and a sanding block) the most effective tool for paint defect removal because you can abrade the paint surface flat until the defects are removed.  Non- diminishing abrasives and a flat foam pad are similar in application to the block wet-sanding process

Collapsed Cell Structure (CCS) Technology™ - foam pads were developed to use on newer clear coat paints. These harder paints require longer polishing times to remove defects. They also help solve the problem of premature "drying". Conventional foam pads absorb water-based formulas, instantly.
This reduces polish and pad performance because most of the polish is trapped below the working surface of the pad. Closed cell structure foam solves this problem with partially closed foam cells, which slow the absorption of liquid, keeping it on the working surface.

(CCS) foam, which means the stiffness of the pad, is focused on to the contact surface, while the rest of the foam remains soft. This type of foam uses intermittent pockets that have been sealed and can no longer absorb polish. This technology was designed to reduce pad absorption at the OEM level, where thinner pads are typically used. This not only extends the workability of water and solvent-based polishes, levellers and compounds, it reduces chemical usage, saves time and makes the polishing process a lot easier. CCS Pads are flat faced. They have dimples across the surface which reduce surface heat at high speeds, and prevent pad skipping.

Lake Country Mfg., Inc. - Products - CCS Foam Pads - http://www.lakecountrymfg.com/ccsfoampads

Pad Application Guide -  http://www.lakecountrymfg.com/padappguide.html


Foamed Wool (Purple) pad - a patented foam process encapsulates the base of the lamb’s wool fibre with microscopic poly-foam particles. Cuts like natural sheepskin but finishes like a foam pad. 

Aggressively removes 1500 grit scratches, leaving a lustrous finish with no hazing by reducing compounding swirls. The foam has a dense body and the fibres resist caking and matting, the foaming process also creates minute air pockets at the base of the fibres, which improves cushioning and retention of compounds and polishes. The manufacturing process produces a uniform material, resulting in consistent pad performance, the Foaming process locks in the lamb’s wool fibres, significantly reducing lint

Constant pressure foam pad- this is essentially a flat pad which uses a patented technology layer of engineered, instant rebound foam between the pad and the backing plate to absorb off-axis movements while keeping the pressure of the pad on the surface constant.

 It allows even beginners to achieve professional-like results, the curved 6- inch pads outer edge makes transitioning seams and uneven panel breaks easier and the concave "dish" in the centre of the pad reduces product splatter, and gives the operator greater pad control. They are very easy to control, and forgiving of less-than-perfect technique.

Variable contact foam pad- provides focused pressure on a reduced surface contact area using the edges of the pad, making this pad ideal for machine polishing. Be aware that increased surface pressure may cause a PC motor to stall. Variable contact pads are more suitable for use with a high-speed rotary polisher
Tufted foam pad-are made from pre-polymer foam with a 50% open cell structure. This 7.5-inch pad has nine- times the surface area of a flat pad. This dissipates heat, spreads polish over a larger area and reduces polish build-up. This pad is ideal for large surface area polishing, such as the removal of oxidation

Contoured Edge pad- these - 7.5-inch pads have a graduated, concave polish pocket similar to the variable contact foam pads, but with a contoured edge and a recessed area for the backing plate. These pads have four distinct working surfaces 

(1) flat for polishing 
(2) they can be ‘lifted’ using the outer 1/3rd of the pad for areas that are tight 
(3)The outer edge of the pad can be used for seams or corners 
(4) the underside can be used for polishing around mirrors, badges, emblems or other thigh areas.
A curved edge foam pad- is ideal for working in tight spaces or a surface with lots of curves. Apply the polish to the outer edge of the pad and the PC can be used at more of an angle, the PC generates very little heat so this application method can be used safely, it’s halfway between a flat and VC pad with surface contact.

This pad can also be used flat, apply more polish on the peak between the curve and recess, utilizing it like this assimilates a variable contact pad.

Meguiar’s DA Microfiber Cutting Discs

Meguiar’s DA Microfiber Cutting Discs are made for maximum efficiency. Their engineered foam interface offers controlled conformability. As you move the polisher over the paint, the microfibers adapt to the curves and contours of the paint, distributing the abrasives evenly for efficient cutting.

The Meguiar’s DA Microfiber Correction System is designed for a dual action polisher! While it won’t replace Meguiar’s 105 and 205 for the removal of wet sanding scratches, this system will work to remove swirls, many scratches, acid rain spots, and other mild to moderate defects on factory paint.

Meguiar's backing plate (W67DA) should be used with their DA Microfiber system as it has shorter Velcro™ hooks Use a pad conditioning brush to clean Meguiar’s DA Microfiber Cutting Discs periodically during use. This will keep the microfiber separated.  Meguiar’s DA Microfiber Cutting Discs are machine washable.

Velcro®

Is a registered trademark of Velcro Industries B.V. it is what George de Mestral named his invention Velcro [: a portmanteau of the two French words velour’s, meaning 'velvet', and crochet, or 'hook']
Generic terminology for these fasteners includes "hook and loop", "burr" and "touch" fasteners. Velcro® is a registered trademark in most countries.

Foam pads are attached to a backing plate (flexible or semi-flexible) with a 5/8" x 11 thread spindle (or a 5/8" x 5/16" adaptor for a Porter-Cable random polisher) and a hook and loop attachment. Velcro® is a brand name of fabric hook-and-loop fasteners.

It consists of two layers: a "hook" side, which is a piece of fabric covered with tiny hooks, and a "loop" side, which is covered with even smaller loops. When the two sides are pressed together, the hooks catch in the loops and hold the pieces together

When removing the foam pad from the backing plate do not just grab the foam and pull or you may find it separates, hold the Velcro and gently pull the pad to prevent any damage. A 5-ich diameter backing plate when used with a 61/2-inch foam pad allows a ¾ -inch `safety' margin' between the edge of the backing plate and the foam pad. To ensure compatibility of fit with a Porter-Cable the post adaptor should be 5/16inch-24.

The foam pad is attached to the machine with a Velcro backing plate; product is then applied to the foam pad. Clean foam pads soon after use, if left saturated for extended periods of time the chemicals used in polish will cause the foam to deteriorate.

Between wool and foam pads, in general, wool pads are considered "cutting" in nature, they also produce less friction induced heat than foam. That is, the fibres of the wool pad "cut" into the paint, removing top layers of paint much more rapidly than foam pads, which do a relatively small amount of cutting but instead rely on greater kinetic friction to do their work.

Purple Foamed Wool (*Purple) - these cutting foam pads are typically used on rotary buffers, but can also be used on a dual action buffer or random orbital. What makes them so effective on a rotary buffer is that it offers lots of cutting power with less risk of damaging the clear coat

Compound/ Heavy Cutting Pad (*Yellow) - a harder more dense open cell pre-polymer foam (70 PPI) composition with an abrasive cutting action, for use with a medium abrasive polish

Light Cutting / Polishing Pad (*Orange) - a middle range, high density open cell pre-polymer foam  (75 PPI) composition with a medium abrasive light to heavy polishing cutting action

Medium Cutting / Polishing Pad (*Green) - high density open cell polyurethane foam (80 PPI) composition with a medium abrasive cutting action

 Polish / Waxing Pad (*White) - a softer less dense blended pre-polymer foam (75 PPI) composition with a light abrasive cutting action
Light Polishing Pad (*Black) - an ultra-smooth open cell polyurethane foam (75 PPI) composition that has very minor abrasive cutting ability
Finishing Pad (* Red) - this open cell polyurethane foam (80 PPI) pad has no cutting or cleaning action but is softer foam than the black pad. It should be used for paint burnishing or to apply a glaze or a finessing polish.
Finessing Pad (* Blue) soft enough composition (85PPI) for applying glazes, sealants and liquid waxes or burnishing paint

Jewelling Pad (* Gold) -this foam is 40% softer than the red making it the best pad for applying your finishing wax or sealant, and for use as a jewelling pad with a fine finishing polish.
Difference between these pads (Red, Blue and Black) is their compressibility
*These colour identifications are for Lake County Manufacturing (LC) foam pads.
There is no common standard colour system used to identify the abrasiveness of foam each manufacturer uses their own colour identification system.
(See also article “Backing Plates”)

General Rules    
                                                            
  1. 1.      Porter Cable 7424 random orbital polisher; the limiting factor to pad size is the actual power of the machine. Using larger pads on these machines actually reduces the amount of polishing power due to the surface resistance of the pad, which will cause the motor to slow down or stall. Conversely using a smaller pad will increase the power available by reducing the surface resistance by concentrating motor power on a smaller area.

  2. 2.      With smaller pads you gain increased control and manoeuvrability. Smaller pads generate more kinetic friction (and subsequently, increased heat) with a PC, which breaks down polishes by generating energy (and applied pressure) over a concentrated area. The random orbiting motion of the PC generates the most power in the centre of the pad (i.e. area of a 6.5 – inch pad is 33 – square inches compared to the area of a 4 – inch pad, which is 12.5 – square inches) This additional pressure / cutting power will facilitate the removal of deeper imperfections

  3. 3.      The opposite is true with rotary buffers. The speed of the outer edge of a smaller (radius) pad is slower than that of a larger (radius) pad. This helps reduce the amount of friction generated, which makes polishing tighter areas much safer.

  4. 4.      Do not use the same pad to apply differing products as cross contamination will reduce the effectiveness or completely negate their purpose altogether. A new or freshly cleaned pad must be used with each type of car care product.

  5. 5.      Water will increase the abrasiveness of a polish; but unlike wool, a foam pad has no fibres to twist, bend, and reshape, therefore helping to loosen the abrasive, so water tends to cause abrasive-clumping, which is detrimental to its performance, it can also cause the pad / abrasive to aquaplane, negating the abrasive
  6. 6.      There is no recognizable standard between manufacturers that use colour as an identification of the abrasiveness of a foam

  7. 7.      Apply pressure to the foam; if it springs back the pad is fine. If it stays compressed the foam core is damaged and it’s time to replace the pad.


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