Newbie Questions About DA Polishers & Abraisiveness

[lovenhim]

Hello everyone. I am in learning mode. As most of you know, I am not a professional at all and I simply want to take care of our family hatchback and my parents 2008 Dodge 4x4 pickup. I know that a lot of newbies are concerned about a DA polisher say a Porter Cable 7424XP burning through or damaging a clear coat finish. I have learned from reading on this site and from watching videos that you would have to be very abusive for that to happen with a polisher like that. Here are my questions and I realize that they are also a "well it depends" kind of question.

How aggressive in grit would an aggressive cutting pad and say a Meguirars 205 compound be compared to sandpaper? I ask this because I understand that wet sanding a scratch with say 3000 grit sand paper will remove clear coat and causes the sanded area to get dull. A combination of a buffing pad and a compound will remove those 3000 grit sanding marks. That tells me that the pad and compound combo must be of finer grit.

If you move on it a polishing pad with a polish, roughly where in the grit scale compared to sand paper are we now?

I am asking these questions so that in my mind I can understand what is really happening on the surface of the clear coat. I understand that a compound and a polish does its job by removing microscopic amounts of clear coat to repair damage. However, it does not seem that a compound or a polish is as aggressive as sandpaper and thus would not remove the same amount of clear coat from the vehicle. I understand that various combos of lag and product will change the aggressiveness or grit rating but I am just interested in brand ranges to help me learn and understand.

[Cruzscarwash]

so without getting into to much detail as there are tons of threads that are VERY specfic on it and many great ones are written by Mike Phillips, but yes at teh end of teh day they all remove clearcoat to get a level surface. sandpaper removes the most, then rotary, then DA. so your combo for a DA can get prety aggessive but in terms in sandpaper where just one swipe to the paint and you can scratch the paint and with a DA you need to spend some time in one spot to do that much damage. ive never seen a DA with a pad and any compound used for 1 sec and it doing really much of anything. with the DA you need to start generating heat to get that type of cut that sandpaper gets.

i tell most not to worry because your really not gonna do to much damage as long as your moving the DA and as long as you dont hit panels with the backing plate, i think thats a bigger and more common issue then the pads and polishes. the free spinning DA's are very forgiving compared to rotary which again generate alot of heat really fast. i beleive if you jump on youtube there is a video that was posted a few months back of 3D doing a test to see how long it takes to actually burn through clear coat and it took close to a min of the DA in one spot to start to do damage.

[Cruzscarwash]

remember a FLEX 3401 is a direct drive so it WILL always spin

YouTube (https://www.youtube.com/watch?v=wEuz-ZbD7q4)

[PaulMys]

I will leave questions like this to Mike, as he would have all of the real world experience to answer them.

That being said, after reading many of your posts I believe you may be over-thinking this.

Pick a product line and pad combo from a line that has caught your eye.

Ask a few questions. Send a few PM's. All of us have our favorites, but none of the senior members here would refer you to any kind of junk IMO.

After you choose, just jump in and get started. All the worrying you are doing over how certain abrasives compare to fine sandpaper is unfounded in my opinion.

Not to dismiss the scientific nature of your post at all. But like I said in the beginning, I'll leave that to Mike P. Get started and go have some fun!

[lovenhim]

I am sure you are right. I am geeky or nerdy like that. I do tend to research things before I jump in, so you are right. I tend to like to know how and why. However, like you have said, reading and watching videos in this case will only get you so far. In this case the pad and polish have to touch paint. LOL I am currently reading a free try before you buy sample of Mike Phillips book. I am enjoying it so far. Thanks for the perspective as I am overthinking this.


I will leave questions like this to Mike, as he would have all of the real world experience to answer them.

That being said, after reading many of your posts I believe you may be over-thinking this.

Pick a product line and pad combo from a line that has caught your eye.

Ask a few questions. Send a few PM's. All of us have our favorites, but none of the senior members here would refer you to any kind of junk IMO.

After you choose, just jump in and get started. All the worrying you are doing over how certain abrasives compare to fine sandpaper is unfounded in my opinion.

Not to dismiss the scientific nature of your post at all. But like I said in the beginning, I'll leave that to Mike P. Get started and go have some fun!

[Cruzscarwash]

Here is another great video to watch worth watching a few times, pretty much explains the entire process


YouTube (https://youtu.be/ulWXODgg8V4)

Sent from my Pixel 2 XL using Tapatalk

[PaulMys]

I am sure you are right. I am geeky or nerdy like that. I do tend to research things before I jump in, so you are right. I tend to like to know how and why. However, like you have said, reading and watching videos in this case will only get you so far. In this case the pad and polish have to touch paint. LOL I am currently reading a free try before you buy sample of Mike Phillips book. I am enjoying it so far. Thanks for the perspective as I am overthinking this.

Please believe me when I tell you that I will research things ad nauseam before buying.

I (all of us) were in your shoes about this at one time or another.

[dlc95]

Maybe a compound would be something like....

20,000 grit, and a finishing polish like 50,000 grit?

[lovenhim]

That was a great video. Thank you very much for the link. I plan on trying all of this on our black Nissan at the end of the week when the weather is cooler with no chance of rain. This will be fun.


Here is another great video to watch worth watching a few times, pretty much explains the entire process


YouTube (https://youtu.be/ulWXODgg8V4)

Sent from my Pixel 2 XL using Tapatalk

[rlmccarty2000]

Rub sandpaper against your skin then rub some compound against the same skin. This will give you a good idea of the level of abrasion.

[SWETM]

We are all little geeky here lol. It's a little hard to say a specific grit you get. Cause it's a 2 part of the cut from the pad and the polish. Then you have the different types of the abrasive technology. Some are non deminishing abrasive and then deminishing abrasive. And to complicate things they also do micro abrasives like many of the meguiars and Griots Garage and 3d has which is non deminishing alike. Then as Menzerna has deminishing abrasive when you start to polish and when they break down they get non deminishing abrasive to the last polishing cycle. Non deminishing abrasive you have the same cut till the polish dries. That's why you see some spritz with destilled water to extend the polishing working time. With a deminishing abrasive like Sonax polishes when it starts to dry you have breaked down the abrasives so you don't have any cut from it left. But have in mind when you break down or work them to long you can work backwards. As the lubrication is gone and the residue in the pad and the cut from the pad can dull it down a bit. So it's often best to find the sweet spot of the working time with the different polishes. And take carpro abrasives which is deminishing, you have a very short working time from. But that is made to have a quick break down of their abrasives. With normal armspeed and speed setting you have 3-5 passes and you are done. Don't remember which brand Mike Phillips used in one write up. But think he did 7-8 passes with that one which are alot. When you get that many passes per sections with a non deminishing abrasive you can get a impresive cut from even a fine polish. And there are much more in the subject than this I'm sure of. It's some of that I have caugth from the internet world. And this is an awesome information on a forum like this.

/Tony

[lovenhim]

Ahhh very interesting. Nice info there. Now, I have Mothers Professional items found here.

Mothers Professional Paint Restoration System (https://www.autogeek.net/mothers-professional-paint-restoration-system.html)
Mothers California Gold Synthetic Wax, Mothers California Gold Wax, car wax, mothers gold wax (https://www.autogeek.net/mothers-synthetic-wax.html)

This is fun and I am enjoying the learning process. Oh, I plan on working on our car later in the week when the high will be uptown 81 with low humidity, and no chance of rain.



We are all little geeky here lol. It's a little hard to say a specific grit you get. Cause it's a 2 part of the cut from the pad and the polish. Then you have the different types of the abrasive technology. Some are non deminishing abrasive and then deminishing abrasive. And to complicate things they also do micro abrasives like many of the meguiars and Griots Garage and 3d has which is non deminishing alike. Then as Menzerna has deminishing abrasive when you start to polish and when they break down they get non deminishing abrasive to the last polishing cycle. Non deminishing abrasive you have the same cut till the polish dries. That's why you see some spritz with destilled water to extend the polishing working time. With a deminishing abrasive like Sonax polishes when it starts to dry you have breaked down the abrasives so you don't have any cut from it left. But have in mind when you break down or work them to long you can work backwards. As the lubrication is gone and the residue in the pad and the cut from the pad can dull it down a bit. So it's often best to find the sweet spot of the working time with the different polishes. And take carpro abrasives which is deminishing, you have a very short working time from. But that is made to have a quick break down of their abrasives. With normal armspeed and speed setting you have 3-5 passes and you are done. Don't remember which brand Mike Phillips used in one write up. But think he did 7-8 passes with that one which are alot. When you get that many passes per sections with a non deminishing abrasive you can get a impresive cut from even a fine polish. And there are much more in the subject than this I'm sure of. It's some of that I have caugth from the internet world. And this is an awesome information on a forum like this.

/Tony

[dlc95]

Rub sandpaper against your skin then rub some compound against the same skin. This will give you a good idea of the level of abrasion.

Or a Rupes coarse blue foam pad!

Ouch!