What makes a foam pad "aggressive"?

S

superstring

New member
Hi Guys



I'm hoping someone can explain what exactly makes one foam pad more "aggressive" than another?



I assume that a more aggressive pad will create more friction between itself and the paint but is it the cell structure or maybe the "stiffness" of the foam or something else that does this?



Thanks!
 
I was wondering that EXACT SAME THING over the weekend and I was planning on posting it at some point....

I was wondering about using the finishing pad for all aspects and letting the individual product/compound do the work....
 
~One man’s opinion / observations ~



The density of the foam and whether you use it wet or dry will affect its ‘cutting’ ability





~Hope this helps~



Experience unshared; is knowledge wasted…/



justadumbarchitect *so I question everything*
 
I'm like you Dale. I only break out the cutting pad if absolutely necessary. For example, After polishing with SSR1 and a polishing pad, I use a finishing pad for my WG polish. Sometimes, I'll use a finishing pad with my SSR1. I've even used SSR3 with a polishing pad!!!
 
Also note that "more aggressive" pads have larger pores, presumably to work better with coarser products. A finishing pad is "tight" pore-wise, while a cutting pad has big ones.
 
I think priming the pad is putting product on the pad before using it, or giving it a quick spray of QD. I believe you can additionally add water to increase the cutting action, but I don't think it's an often used technique.
 
Accumulator said:
Also note that "more aggressive" pads have larger pores, presumably to work better with coarser products. A finishing pad is "tight" pore-wise, while a cutting pad has big ones.
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I'd have to disagree. I have a finishing pad that has small pores (Edge) and another with large pores (LC). I think the "hardness" of the foam is the determining factor, since that affects how "hard" you push an abrasive particle into the surface. The pores are too large with respect to the abrasive particles so that shouldn't matter, although pore size does seem to affect how much product you push against the surface at once. In that sense, maybe the smaller pore pads cut faster or cause a product to break down faster.



Oh, I just read that a denser pad causes a product to stay wet longer.
 
~One man’s opinion / observations ~



How/why would you use a pad "dry"?

A: With a non-abrasive polish, if you use a damp pad it will become very slightly abrasive.



The abrading ability of any polish can be changed by their application method (i.e. machine or hand application, speed and/or pressure used, using wet or dry and/or type of foam (different foam compositions have a differing abrading ability) The work is approximately distributed, 60% product, 30% foam composition and 10% pressure applied and/or speed of rotation or oscillation.







~Hope this helps~



Experience unshared; is knowledge wasted…/



justadumbarchitect *so I question everything*
 
There are multiple factors that make a foam pad more or less “coarse�. It starts with the polyurethane resin. A catalyst is added to the resin that causes a chemical chain reaction.

The polyurethane resin contains a carbon molecule that’s sandwiched between two electronegative atoms, oxygen and nitrogen. Electronegative atoms suck electrons away from other atoms, so the nitrogen and the oxygen leave that poor carbon really lacking for some electrons. As the mix is blending, water is added. The H2O comes to the rescue of that poor carbon and donates a pair of its electrons. Now satisfied as far as electrons are concerned, one of the electron pairs the H2O shared with the nitrogen (now in a double bond), leaves and rests right on top of the nitrogen, giving it a negative charge. Nitrogen molecules really dislike being negatively charged, so the nitrogen looks for a way to balance the charge. It solves its discomfort by swiping a hydrogen from the water. From this simple reaction, carbon dioxide gas is expelled. The amount of gas produced helps determine the size and density of the cells in the foam.



There are eight measurements used in the foam industry to identify foam qualities:



1. Density

2. Compression

3. Sag Factor

4. Fatigue loss

5. Hysteresis

6. Tensile

7. Elongation

8. Tear



It would take about 10 more pages of typing to go into each one of these factors/measurements. However, to answer the original question correctly, it is compression, hysteresis, and tensile that have the most to do with the “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. A pad that holds a good volume of polish allows the polish to do the cutting job instead of the pad.
 
~One man’s opinion / observations ~



Thanks for your explanation DavidB, clear and concise as usual.



There is usually a very fine line between marketing ‘hype’ and what could be defined as liable, contributions by knowledgably members of this forum help members differentiate between the ‘hype’ and what is factual, whereas Joe public has only the information a manufacture gives them.



~Hope this helps~



Experience unshared; is knowledge wasted…/



justadumbarchitect *so I question everything*
 
Just an FYI note for those not aware, it was Meguiar's that invented the foam pad industry some 26+ years ago. While the makers of wool pads scoffed and laughed at Meguiar's, look at the industry now.



Do you think that Meguiar's might have a bit of knowledge in this area? Again, debunk the myth going around that Lake Country is the only brand name you can trust.
 
DavidB said:
Just an FYI note for those not aware, it was Meguiar's that invented the foam pad industry some 26+ years ago. While the makers of wool pads scoffed and laughed at Meguiar's, look at the industry now.



Do you think that Meguiar's might have a bit of knowledge in this area? Again, debunk the myth going around that Lake Country is the only brand name you can trust.
Click to expand...



David-actually, Meguiar's invented foam pads almost 40 years ago! Mike Phillips showed us one from the 60s at the Autopia/Meguiar's meet.



BTW, after using several Meguiars pads and the pads I got with your PC + pads special (still $179!), I can attest to how good both Meguiars and your pads are.
 
DavidB said:


There are multiple factors that make a foam pad more or less “coarse�. It starts with the polyurethane resin. A catalyst is added to the resin that causes a chemical chain reaction.

The polyurethane resin contains a carbon molecule that’s sandwiched between two electronegative atoms, oxygen and nitrogen. Electronegative atoms suck electrons away from other atoms, so the nitrogen and the oxygen leave that poor carbon really lacking for some electrons. As the mix is blending, water is added. The H2O comes to the rescue of that poor carbon and donates a pair of its electrons. Now satisfied as far as electrons are concerned, one of the electron pairs the H2O shared with the nitrogen (now in a double bond), leaves and rests right on top of the nitrogen, giving it a negative charge. Nitrogen molecules really dislike being negatively charged, so the nitrogen looks for a way to balance the charge. It solves its discomfort by swiping a hydrogen from the water. From this simple reaction, carbon dioxide gas is expelled. The amount of gas produced helps determine the size and density of the cells in the foam.
Click to expand...



Your anthropomorphizing of chemistry amuses me. Normally, I would have done something boring myself and just said, "go here: http://www.psrc.usm.edu/macrog/foamsyn.htm"
 
I’d like to make a public apology to Nick@DParadise for my “cheap shot� regarding his discussion of LC pads on Roadfly. I edited my original reply in this thread to remove my personal remark regarding Nick’s "LC is the only company to make foam specifically for automotive paint care." statement. While I do not believe Nick’s statement is true, my comment was inappropriate. Sorry, Nick!
 
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