I'll appreciate your advice

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07090

New member
I bought a porter cable DA 7424 xp to use on my car's. I've always been anal about keeping my cars clean and I'm tired of staring at scratches and swirls. My budget isn't unlimited and I like to do things myself so after reading a bunch on this site, I made the plunge.



I have 2 older cars that really need some love beyond just a wash and dry.



When I purchased my kit, I bought the orange and green Lake Country cutting pads but not the yellow (most aggressive). I am using Meguiar's Ultimate Compound off the shelf from Pepboys. It states on the bottle that it can be used with hand or machine. My initial thinking was that I didn't want to get too aggressive as I hadn't yet even used the tool on a car.



My issue now is that my work is only taking out the light scratches and swirls. It is making some of the deeper swirls lighter and the deep scratches lighter but it isn't making them disappear completely. For all intensive purposes, my work is great. The car's look a million times better and my wife and neighbors are amazed and want me to do their cars or lend them my tool (tough luck!).





My general pattern is



1. Wash & Dry

2. Clay (when clear feels rough)

3. DA medium cutting pad with ultimate compound

4. DA with light cutting/finishing pad with M205

5. DA with blue finishing pad with NXT 2.0 tech wax (also states that it's for hand or machine)



For technique, I've been going east-west and then north-south starting at speed 3 on my DA and making it faster as my work progresses and I've always worked on the panels when their cold. Either early morning or evening in the shade.



I just ordered the Yellow Lake Country and the M105 so that I can get a little more aggressive with the finish. Should I also be using a different product for waxing? Will this be what I need that gets me over the hump and gets rid of the swirls and light scratches completely?



Is there anything I should be doing post step 5? Would a glaze bring back that showroom finish like when they were new?
 
Diagnosis is the key, not guess work; before deciding on what products to use ascertain the paint surface conditions and your goals for the paint finish. And then proceed with the least abrasive product / pad combination



Differing density (hardness) of paints react differently to correction, so before beginning to polish measure the paint thickness (PTG) panel by panel to ensure that you do not select an aggressive polish that will remove too much clear coat



The key to the polishing process is to know how the paint will react with each pad / polish combination you consider using. You must know your product and what its capabilities are before using it. This is why a ‘test’ spot is so important. The factors that affect the outcome -speed, friction (kinetic energy) applied pressure, foam pad actual surface contact area, pad grit number (abrasive ability) amount of surface lubrication available, the surface area and heat conductivity of material



Select a ‘typical’ panel; one that represents the type of defects that you want to remove and the finish level required. Select an area of 24 x 24-inches and tape it off with painter’s tape, as this is an optimal working section to perform a product test spot; this will help establish a polish – pad combination that will produce the best possible finish that corresponds to your detailing goals for the vehicle. Pay attention to how the paint is responding to your inputs. Stop and evaluate your progress, once this is established; repeat the process over the entire paint surface, adjusting abrasiveness for any low paint thickness.



There may be some areas that have deeper scratches, which will necessitate a more abrasive polish. This is known a ‘spot-correction’. Once this area(s) are completed revert to the original polish / pad combination, there is no need to remove any more clear coat than is necessary
 
Thanx for that. I've found most of my paint to be responding really well to the regime I've been using but I haven't been as successful with the spot-corrections. I'll do some searches for spot-corrections as well to see what techniques are available.



Thanx for the tip on the 2*2 area. I'll do that the next time I pull out my PC.





What about the finishing side of the job, should I be adding a glazing step as well?
 
The test area is a good suggestion. The problem is, most people think they have moderate to light swirls when they have pretty intense swirls. Intense swirls take several passes, especially with a PC and pads that aren't very aggressive. The problem comes when you start getting the deeper swirls out. Unless you've been doing this long enough, you won't know and you will have to resort to using an instrument to tell you how much paint is left. I'd hesitate to do any more than 3, maybe 4 passes with UC on a heavy cutting pad without taking measurements.
 
Dan said:
The test area is a good suggestion. The problem is, most people think they have moderate to light swirls when they have pretty intense swirls. Intense swirls take several passes, especially with a PC and pads that aren't very aggressive. The problem comes when you start getting the deeper swirls out. Unless you've been doing this long enough, you won't know and you will have to resort to using an instrument to tell you how much paint is left. I'd hesitate to do any more than 3, maybe 4 passes with UC on a heavy cutting pad without taking measurements.
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Thanx Dan, I just checked out how much a gauge was and I don't think I'll be buying one. It'd be cheaper for me to repaint a couple panels!
 
The highline II is about $250, not sure what sort of paint job you'd get for that. But if you post up your location (in your profile), there might be someone close by that can help you get some readings.
 
07090-Welcome to Autopia!



I prefer, and recommend, the new MF cutting pads over the yellow foam cutting pads, which I *DO NOT* like or recommend.



I'd turn up the PC to speed 6, or at least 5.



I myself prefer to work areas smaller than 2' x 2'.



Keep the pads clean; don't do a whole panel before you stop to clean the pad.



Study up on the Kevin Brown Method for tips on how to use these Meguiar's products, and pay close attention to how to properly prime the pads.
 
Another vote for the MF pad over a yellow pad. If it is a factory paint job, chances are you won't be able to do the heavy spot correcting without sacrificing too much of your paint thickness. I generally tell people if you can catch the scratch with your fingernail, it isn't worth it to try to compound out. You'd probably have better luck testing your hand at some touch up painting :D
 
SpoolinNoMore said:
Another vote for the MF pad over a yellow pad. If it is a factory paint job, chances are you won't be able to do the heavy spot correcting without sacrificing too much of your paint thickness. I generally tell people if you can catch the scratch with your fingernail, it isn't worth it to try to compound out. You'd probably have better luck testing your hand at some touch up painting :D
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Touch-up paint? That sounds like a recipe for disaster.
 
I'd go MF disc cut, they cut more efficiently generally and can finish down better, depending on the clearcoat hardness.



I'd look at alternatives to NXT 2.0 too perhaps - it's okay, but average durability wise.
 
Dan said:
The highline II is about $250, not sure what sort of paint job you'd get for that. But if you post up your location (in your profile), there might be someone close by that can help you get some readings.
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My location is pretty easy, it's in the 07090! North-Central NJ :)
 
RussST said:
I'd go MF disc cut, they cut more efficiently generally and can finish down better, depending on the clearcoat hardness.



I'd look at alternatives to NXT 2.0 too perhaps - it's okay, but average durability wise.
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Can I trouble you for a link to MF disc cut, I'm not sure what that is.
 
Another vote here for the MF cutting disc. Used in conjunction with Megs D300 compound, you will be able to remove most defects in one step. For 99% of people out there, the finish will be more than good enough to go straight to you sealant after. Run the PC at speed 5/6 with slow arm movements and just moderate pressure to get the most of the discs. The other option wold be to get the B&S Yellow compounding pad. Unlike the LC one, it will leave a very nice finish as well.
 
RussST said:
We only have Optimum Polishing Discs over here so far, no Cutting :(



I keep killing the Megs ones - either velcro separating or them going 'egg shaped'!
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I've killed 2 discs pretty much back to back. You have to be very careful of heat and make sure you don't go over 3500 OPM.
 
SpoolinNoMore said:
I've killed 2 discs pretty much back to back. You have to be very careful of heat and make sure you don't go over 3500 OPM.
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Funny, I haven't had any problems with my Meguiar's MF cutting disks. Both sizes are holding up fine even when used at speed 6.
 
07090 said:
What do you prefer in the MF pad? Does it cut more or less? With more control?
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I find they cut better and leave a nicer finish. Less heat too, so safer.



Touch-up paint? That sounds like a recipe for disaster.
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If you use a sovent-based "leveling system" (e.g., Langka or DrColorchips) there's litte chance of disaster. If/when the touchup doesn't look like an improvement, just wipe it off with the solvent. If/when it does look OK, use the solvent (very gently) to level out the "blob of paint" so it blends in a little better.



The disasters related to touchups usually involve attempts to level/blend the touchup via wetsanding, whicha) *is* the best way to do it if you know what you're doing and b) is an easy way to cause big problems if you *don't* know.
 
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