as per meguiars...heat not needed to break down abrasives

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imported_rfinkle21

New member
I was just on the Meguiars forum, and it was said that there is no need for heat for the meguiars polishes to break down.



i see a great deal of people who use rotarys explain the advantages of the machine come from the heat they generate...



hoping someone would comment...



In theory, if heat is not needed, a PC could do every task a raotary could perform, but just take a multiple of time.
 
I saw that thread too.

I do think a PC can do a lot compared to a rotary, just not in the same amount of time.

The rotary isn't just heat, though. Most of a PC's energy is used to 'jiggle' the machine around, while a rotary transfers most of its energy straight onto the paint.
 
I tihnk it's because the rotary just makes more actual torque and movement when on the paint. As Mad iX said, the jiggling the PC does takes away from the circular motion it makes.
 
Note that all products don't work (i.e., break down) the same way as Meguiar's products. Heat might be required with some other stuff but not with Meg's products.



Still, I wonder about this whole idea of heat not being required with Meguair's "rotary only" products...not to start some :argue: but why are some Meg's products rotary only if they'll break down without heat, given enough time? AFAIK, if you take something like #1 Medium Cut to b/c paint with a PC you're gonna instill marring that you won't get out with a PC. If I used many Meguiar's abrasives (or if I were possessed of greater intellectual curiosity), I'd pop over to MOL and ask about this.



Mitchubishievo- The idea as per this discussion of Meg's stuff is that while friction generates heat, said heat is just an unnecessary byproduct of the process and not the reason why things are happening.
 
Mitchubishievo said:
But then, friction creates heat...
Click to expand...



Yup, but according the Mike Phillips, it's the friction itself and not the heat that is required to break down the abrasives. There's no doubt that the rotary action produces heat.



Whatever the case, the rotary is definitely still a dangerous tool in the wrong hands, and much more powerful than the PC. Whether a particular product requires the heat or just the friction of the rotary is a moot point, because the PC can provide neither.



That's the way I see it anyway.
 
Yes, friction is a physical force. Just like when you rub confectionery in your hands, it will break into smaller pieces. Heat on the other hand will only cause the material to melt. I'm sure the melting point of the abrasives is pretty high. So it should be friction that breaks down the abrasives.



A rotary just makes more efficient use of the abrasives before it breaks down compared to a PC.
 
Mitchubishievo said:
But then, friction creates heat...
Click to expand...





Right, but what I was saying is that the actual mechanical action of rubbing the abrasives on the surface, is what wears them down.
 
I haven't seen the thread at Meg's forum, but just because a PC can break down the diminshing abrasives in Meg's polishes, does that automatically mean it can do the same job as a rotary? I would hazard to guess that is not the intended message.



I can see how, even if the PC can break down these diminishing abrasives, the rotary will still offer the extra power (speed & heat) to get the job done faster. How much faster can you sand a piece of wood smooth with 100 grit sandpaper on a power sander as compared to using 100 grit by hand with a sanding block? You can eventually wear out that sandpaper by hand, and get the hunk of wood smooth, but the machine will do it much faster.
 
If the oils in a product dry out before the abrasives have broken down you'll lose lubrication and the particles will just grind themselves into the paint rather than cutting and removing. You'll get swirls instead of gloss.



If the abrasives in a product need the extra power of a rotary to break down in a timely manner but you use a PC instead you'll have the same exposure time to evaporate the volatiles but the abrasives won't be breaking down at a fast enough rate.



I could see why some products might need heat to work effectively. As the temperature of a finish increases the paint becomes softer. It would make sense that some types of cutting particulates work best in a specific range of coating hardness. If the range is narrow and on the soft side you would need the temperature to go up before you get effective cutting.



Unfortunately, if the finish gets too soft it will be much more likely to swirl, abrade too thin or burn.



Polymers have a characteristic called the glass transition temperature. This is the temperature (actually, it's more a zone of temperature) below which the material is hard (elastic) and above which the material is soft (plastic). Once you cross the glass transition temperature the wear characteristics of the material (resistance to indentation, material removal rates, ability to maintain gloss) change dramatically.





PC.
 
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