Don't steer away from exploring paths less traveled

[ZoranC]

#1,3,4- The failure has to do with the velcro backing only being glued onto the pad itself. ... I'm not sure why you aren't happy with my responses but I am just letting the rest of the people on the board know of the other options "off the beaten path". ... I have used various pads and the 7.5" pads are excellent- I see no reason to use any other size or type pads. ... That is unless someone comes up with a smaller pad that looks like these pads, ...

Me not being happy with your responses is incorrect percpetion. I am actually happy to see different approaches and points of view and debate them, as much of your approach of going bigger as mine of going smaller, because thinking differently than beaten path is major point of this thread, like you too pointed out.



What I was trying to point out though is that I was talking about pad size while you were concentrating majority of pros for 7.5" on features of certain implementation that have nothing to do, like you too yourself said, with size. I agree that they are good features, but again would like to see that noticed and separated so it doesn't become apples and oranges. I feel it says a lot when you say you would go for 5" if you could find them with same features.

I have used these pads. I don't see any differences in the bogging or reduced cutting times. There's a reason why you can't believe it doesn't bog the maching down- that's because you haven't tried it. You can either take my word for it or go out and buy the pads to try and prove me wrong...

You are right that I haven't tried 7.5" pads to see will they bog down. I feel spending money to see whether that will happen or not would be a waste because if 6.5" ones bog down on me, like they sometimes do, 7.5" ones will, assuming they are made from exactly same material in exactly same straight edge shape and I apply exactly same pressure on them, bog down even easier, or to be precise 33.14% easier because that's how much surface area of 7.5" is bigger than surface area of 6.5" and resistance to movement (friction) is proportional to surface size. It might be just 0.5" bigger on both sides but 33% bigger is 33% more resistance. Of course, that is assuming they have staright edge. And if they don't have straight edge so their contact area is smaller than what ot should be based on size then what's the point?

 

[coupe]

I look at it this way based on what i know about the machine and the polishes.



Polishes need heat and pressure to break down.



The PC was designed for small, light weight sanding disks.



Well from my experiance 7" pads that are soaked with polish are heavy and the PC just dosent have the power to keep the pad moving, the slightest pressure stops them from moving at all. So i thought well, if i can get a smaller pad (mimicking the use of a sanding disk) the PC should be able to keep it moving and i should be able to create the pressure and heat necessary to properly break down the polish and do it in a timely manner. Well i was right, it worked the way i thought it would.



Going off my experiance with 7" pads i cant imagine the 7.5" pads being any different. With my 7" pads if i looked at them wrong they stopped moving.

 

[ZoranC]

I look at it this way based on what i know about the machine and the polishes. ... So i thought well, if i can get a smaller pad (mimicking the use of a sanding disk) the PC should be able to keep it moving and i should be able to create the pressure and heat necessary to properly break down the polish and do it in a timely manner. Well i was right, it worked the way i thought it would.

I used different line of reasoning for same result. Mine was "If 6.5" pads work but are sometimes too big for some areas of my car so they get in my way, and 4" would work in those areas but might be too aggressive and too small to do whole car with, then 5" to 5.5" ones have a chance of being happy medium". It worked way better than I thought/hoped. So much I was shocked how easy it was to work with them and how much less effort I needed. I definitely have to try 5.25" CSS from Danase.

 

[xtahoex]

First of all let me say that I do not like large pads I was just trying to put a reason behind why they may work for some people. That being said the reason behind a 4" pad being aggressive is different than my reasoning (although it may be incorrect) for a 7.5" pad being aggressive. A 4" pad is aggressive not just because of speed but because any pressure applied is spread over a much smaller "footprint" this also means that more pressure can be applied while not slowing the machine down as much. Thus the reasons for a 4" pad being more aggressive are both pressure and speed, whereas my reasoning for a 7.5" pad being aggressive was only speed. So to answer your response ZoranC yes the outside edge of larger pad may actually spin faster than a smaller pad but the smaller pad could still be more aggressive because of its combination of speed and pressure.

 

[imported_Nimble]

Best deal IMO. 5.5 inch Dual Action Pad Combo

 

[ZoranC]

That being said the reason behind a 4" pad being aggressive is different than my reasoning (although it may be incorrect) for a 7.5" pad being aggressive. A 4" pad is aggressive not just because of speed but because any pressure applied is spread over a much smaller "footprint" this also means that more pressure can be applied while not slowing the machine down as much.

Not being knowledgable on why pads work the way they work here are some thoughts I wonder about:



1. If 4" is more aggressive because of higher pound per square inch achieved would it be less efficient than 7.5" if pressure is applied in such amount that it results in same pressure per square inch?



2. Same amount of pressure per square inch will still result in smaller pad bogging down less (total amount of friction will be smaller). Which role this plays?



3. Smaller pad dissipates less heat. Everything else being equal how much that smaller heat dissipation contributes to aggresiveness?



4. Considering path of DA is not same as one of rotary what is the real difference in path spot at the edge ends up traveling when compared to spot in the middle? I wonder because on some sander designs every single spot on the surface ends up traveling equal distance.

 

[xtahoex]

That's very interesting about the sanders surfaces all covering the same amount of distance. I did not know that and I wonder if it is possible that the same is true for a PC. I wish we had some way of knowing the answer to the rest of your questions. The only one I can guess at would be #1 I do not think that the 7.5 would be as aggressive with the same Lbs/in because at that point I think the machine would bog down so much it might barely be moving. At least that is how it seems to me.

 

[ZoranC]

That's very interesting about the sanders surfaces all covering the same amount of distance. I did not know that and I wonder if it is possible that the same is true for a PC.

Some of them (at least that's what I have been told). Makes sense because otherwise sandpaper would not be wearing down evenly. Which begs for question: Do 7.5" pads used on PC show sign of being worn down more closer to the edge you get?