How much pressure to apply with PC?

[Superdutytd]

Yea I have no idea on weight. Do you add more weight to a harder clearcoat or less?

[Junkman2008]

... I keep hearing so many different weights is because there is some leeway and there is not one set way. Wish I could get some hands on training.

 

There is some leeway depending on what setting you use. I don't like to go up to the setting of 6 because the PC acts out of control on that setting. However, you can apply a lot more pressure on that setting. On a setting of 5, I hardly apply any pressure at all. I can do a lot of cutting at that setting with my technique.

 

You're right, until you get your hands on a PC and actually get a lot of practice in, you will always be confused on what to do. Only when you apply the various techniques you have heard, will you obtain first hand knowledge of what works because you will see the results first hand after applying each technique. This is why I like making videos that show my technique and results. You get to see first hand the results of my methods. Who are you going to believe? Some guy in Amsterdam or your lying eyes?

 

That was me being sarcastic. Your eyes don't lie!

 

Yea I have no idea on weight. Do you add more weight to a harder clearcoat or less?

 

Again, it is not about how hard the clear coat is, it is about maximizing the effectiveness of the PC. Which do you think does the most work: the PC cutting at maximum performance or the PC cutting at less than maximum? The obvious answer is the first choice, no matter how hard the clear coat is. The only thing a harder clear coat is going to do is cause you to have to make more passes. If you are not maximizing the cutting action of the PC, then not only are you going to have to make more passes, you're going to have to make A LOT more passes.

 

The polish does not get more powerful when you apply more pressure. The pads do not change density or anything else when you apply more pressure. The clear coat on the car does not change when you apply more pressure. The only variable that changes when you apply more pressure is the SPEED that the PC spins at (oscillation remains the same). The faster the PC spins, the more clear it is cutting.

 

That's why a true rotary buffer is so effective . It spins a hell of a lot faster than the PC. The key to cutting is the spin!

[Superdutytd]

Man I feel like a total NOOB.

 

You want the PC spinning right? So you would want to use just enough pressure to keep the pad pressed against the surface?

[Junkman2008]

Man I feel like a total NOOB.

 

You want the PC spinning right? So you would want to use just enough pressure to keep the pad pressed against the surface?

 

Exactly. It is the combined actions of the (dual-action) polisher in which maximum results are obtained.

 

If you shove too many cloths into a washing machine, the cloths will not get clean. Why? Because the action of the washer in conjunction with the action of the clothing rubbing against each other, along with the added detergent is what gets the cloths clean. You can look at the soap in the washer as polish to a clear coat.

 

If you eliminate the action of the clothing rubbing against each other (the rotation of the PC's pad) and simply rely on the action of the washer (the oscillation of the PC), the clothing will get cleaned a little (because of the soap and the washer's movement), but the clothing will in fact still be dirty. Shoving too many cloths into the washer is like putting to much pressure on the PC.

 

Using this analogy, we can see that both actions of the polisher in conjunction with the polish are all equally important. If you remove or dampen any of these 3 components, You have just affected 1/3 of your effectiveness.

[Superdutytd]

Okay thank you. I still cannot seem to remove some buffing holograms out of my paint (the paint is TOTALLY swirl free except for these 'deep' lines). I worked on my hood for hours and they are still there. I wish i knew how to wetsand. My hood has been repainted but I'm still not going to try it out.

[Junkman2008]

Okay thank you. I still cannot seem to remove some buffing holograms out of my paint (the paint is TOTALLY swirl free except for these 'deep' lines). I worked on my hood for hours and they are still there. I wish i knew how to wetsand. My hood has been repainted but I'm still not going to try it out.

 

It would be great if you could take some pictures using light as I do in my pictures to show me the condition of your paint. I need to know what you are calling "lines" and "holograms". I may be able to suggest a solution. Also, what combination of equipment/pads/polish are you using to work on this issue?

[Tundra5-0]

Sometimes you have to except that deep scratches are a lost cause. Like I tell people I detail for "when I polish I'm taking a micro layer of paint (clear) off, but I cant put it back on. I dont want to do more damage to their vehicles. I can point out to them what will come out and what wont. I dont want to pay for a paint job!

The Jeep Cherokee in my thread under trucks has key marks on the hood. One trick you can do to help mask a scratch is to take some compound and rub in the direction of the scratch and then polish. This reflects the light in a different way. In the pics you cant see the scratch unless (they are still there) you right on top. These were very deep.

[Superdutytd]

AJ I would love to but I have nothing to wash/clean the car with. I'm not sure if holograms are the correct term but they are long deep swirls if that makes sense. There are probably a total of like 10 on the hood, i'm figuring from the body shop.

 

I started out using SHR with an orange pad, PC on 5k, then 6k.

That removed the swirls (and left some tiny tiny buffer marks, which i thought was weird, I'm using an LED light to look at the paint, I know not some halogens but I don't have any here)

I then moved onto some M105 with a white pad at 5k, which seemed to diminish them but they are still there. I literally worked on the paint for hours, back and forth and they seemed to get better but are still there. If a scratch is going one way do you apply polish with it or against it? Or both?

[Junkman2008]

AJ I would love to but I have nothing to wash/clean the car with. I'm not sure if holograms are the correct term but they are long deep swirls if that makes sense. There are probably a total of like 10 on the hood, i'm figuring from the body shop.

 

I started out using SHR with an orange pad, PC on 5k, then 6k.

That removed the swirls (and left some tiny tiny buffer marks, which i thought was weird, I'm using an LED light to look at the paint, I know not some halogens but I don't have any here)

I then moved onto some M105 with a white pad at 5k, which seemed to diminish them but they are still there. I literally worked on the paint for hours, back and forth and they seemed to get better but are still there. If a scratch is going one way do you apply polish with it or against it? Or both?

 

What is M105?

 

You should have followed the SHR with the Fine Machine Polish. Go back and read my post #20 in this thread. The Adam's line has been engineered to work together. By jumping around with different brands, you defeat the results that you are trying to achieve. As a new detailer, you should stick to a proven system that has already been designed to work together. Jumping around between brands is for the professional who has used products extensively and knows beforehand what the results will be.

 

This helps me understand why you are not getting the results you want. Did you see how bad of a shape that hood was in that I fixed in my video? If I can get swirls out of that hood with Adam's product, your hood would be a cake walk. Youi have to work the program and it will work for you. Adam's has done the hard part (engineering), all you have to do is follow his directions.

[Z51L9889]

I just tried my PC and Adam's SHR/FMP/MSW for the first time last night on my son's 10 y.o. Civic (aka the practice vehicle). The clear on the hood looked like the surface of the moon up close during my "before" inspection.

 

I started out with the PC set to 5 using minimal pressure and didn't see any change after two passes with SHR. I then watched Adam's video and tried it again with fairly heavy pressure and moving more slowly (about 1/2 as fast) and saw a considerable improvement. After two passes of SHR and one pass of FMP, most of the scratches and some of the smaller pits were removed but there was some inconsistency in the quality of my final finish across the hood. Overall, it looks 1000% better, but this got me thinking about how I can obtain better consistency.

 

Junkman is absolutely correct that by leaning on the PC until it doesn't rotate cuts down on the amount of work the machine can do. We then do the work instead of the machine. The product needs to be subjected to a certain amount of shear for a given surface to polish effectively. The shear is a combination of motion and pressure. When we lean on the buffer, we add a bunch of pressure but cut the motion in half. If we apply minimal pressure, we get the full effect of the mechanical action of the PC but we will need to make more passes over the area vs. using high pressure to properly break down the product.

 

It seems to me that I probably didn't see the results I wanted with minimal pressure due to moving the PC a bit too fast and not fully breaking down the product. Further, I think that the variation in results I saw across the hood was in large part due to variation in the amount of pressure I was applying to the buffer. I think I would see better consistency with minimum pressure because I remove the prime source of pressure variation (the buffer operator) from the equation.

 

I have only completed the hood thus far. I will try minimum pressure on the roof and compare the results.

[Superdutytd]

I did go over the hood with the FMP on a white pad(on 6k) after going over with the SHR and even though the hood looks amazing (no swirls) and shines like a mirror these scratches are still there. I extensively worked the areas (taped off 2 square ft at a time).

 

I don't understand because there are only these left as they look just like long swirls, I guess what I'm going to call hairline scratches, that run down the hood.

 

I know you're probably going to chastise me about this but M105 is Meguiars new 'DA approved' heavy cut polish that I use when I detail gelcoats. I use M105 on 4" orange pads when I am removing swirls/scratches off boats.

[Baron_Von_Awesome]

I did go over the hood with the FMP on a white pad(on 6k) after going over with the SHR and even though the hood looks amazing (no swirls) and shines like a mirror these scratches are still there. I extensively worked the areas (taped off 2 square ft at a time).

 

I don't understand because there are only these left as they look just like long swirls, I guess what I'm going to call hairline scratches, that run down the hood.

 

I know you're probably going to chastise me about this but M105 is Meguiars new 'DA approved' heavy cut polish that I use when I detail gelcoats. I use M105 on 4" orange pads when I am removing swirls/scratches off boats.

 

Don't go too crazy with the M105 - if it didn't come off with one or two passes of the 105, it's best to just walk away (for the unfamiliar - M105 has much, much more bite than Swirl/Haze Remover). And if it is a buffer hologram from a body shop, normally something finer like FMP (or even M205) takes them out with 2 or possibly 3 passes. The fact that they're still there after you putting so much effort into the hood tells me it's possibly more than just buffer holograms - even if you had bad technique the holograms would be gone by now.

Edited May 13, 2009 by Baron_Von_Awesome

[Superdutytd]

Yea I did not go overly crazy with it and it was on a white pad. Just 3 or 4 passes on 5k. I might take this to a professional and have them take a look at these marks.

[Bill-V8V]

Try real hard to get us some picture before you take it to a professional, we might be able to help you save some money :2thumbs::2thumbs:

[Superdutytd]

Yea I will. I am not going to be taking it to have it done up by a professional but just to see if they know what they might be from. I am going to hopefully have all of my stuff (including my new polisher) here in about 2 weeks.

[Baron_Von_Awesome]

Again, it is not about how hard the clear coat is, it is about maximizing the effectiveness of the PC. Which do you think does the most work: the PC cutting at maximum performance or the PC cutting at less than maximum? The obvious answer is the first choice, no matter how hard the clear coat is. The only thing a harder clear coat is going to do is cause you to have to make more passes. If you are not maximizing the cutting action of the PC, then not only are you going to have to make more passes, you're going to have to make A LOT more passes.

 

The polish does not get more powerful when you apply more pressure. The pads do not change density or anything else when you apply more pressure. The clear coat on the car does not change when you apply more pressure. The only variable that changes when you apply more pressure is the SPEED that the PC spins at (oscillation remains the same). The faster the PC spins, the more clear it is cutting.

 

That's why a true rotary buffer is so effective . It spins a hell of a lot faster than the PC. The key to cutting is the spin!

 

That depends on the polish being used. Non-diminishing abrasives are most effective on a PC when applied with 15 - 20 pounds of pressure until the polish is properly worked in and broken down. They obviously don't become more powerful (although that would be really cool), but that is their element - non-diminishing abrasives like pressure: them and a Porter Cable are peas and carrots - they just belong together. If you used little to no pressure when correcting by PC on a new Audi or Mercedes with a ceramiclear finish, for example, you'd be there for the remainder of your natural life waiting for results; if you use moderate pressure, you can be home in time for dinner.

 

There is obviously a peak where additional pressure is going to yield no benefits, but adequate pressure must be used with a Porter Cable - it breaks down polishing abrasives using friction generated from its oscillating motion and...pressure. Doing otherwise while trying to correct paint would be wasting time. It's the only way it can work since there is no forced rotation like that of a circular or true dual-action polisher (which relies on heat and friction generated by forced rotation to break down polishes).

[Superdutytd]

Non-diminishing abrasives can be dangerous because they continue to cut at a high rate even when you've used them a while right?

[Baron_Von_Awesome]

Non-diminishing abrasives can be dangerous because they continue to cut at a high rate even when you've used them a while right?

 

That is true - but only really when talking about compounds instead of polishes. It also varies depending on the brand as well - they're all different. But non-diminishing polishes are perfectly safe - Meguiar's is an example (Adam's may be too...?). Most polishes geared toward use with a PC - "DA Approved" - are non-diminishing.

[Junkman2008]

That depends on the polish being used. Non-diminishing abrasives are most effective on a PC when applied with 15 - 20 pounds of pressure until the polish is properly worked in and broken down. They obviously don't become more powerful (although that would be really cool), but that is their element - non-diminishing abrasives like pressure: them and a Porter Cable are peas and carrots - they just belong together. If you used little to no pressure when correcting by PC on a new Audi or Mercedes with a ceramiclear finish, for example, you'd be there for the remainder of your natural life waiting for results; if you use moderate pressure, you can be home in time for dinner.

 

There is obviously a peak where additional pressure is going to yield no benefits, but adequate pressure must be used with a Porter Cable - it breaks down polishing abrasives using friction generated from its oscillating motion and...pressure. Doing otherwise while trying to correct paint would be wasting time. It's the only way it can work since there is no forced rotation like that of a circular or true dual-action polisher (which relies on heat and friction generated by forced rotation to break down polishes).

 

Well, I don't want to confuse the subject by introducing the many variables that can be debated, I just want to advise those using the Adam's product line. I've never seen a clear as hard as the one on the Corvette and the technique I described has worked with ease on every Vette I've worked on.