Meguiar's 85 compound, how to use it with a porter cable 7424xp?

[Maruzo]

Dear Gentlemen,

I just bought a bottle from amazon.com. Want to try it on the black hood of my 15 years old benz. I already cleaned the paint surface by washing, claying, and then 2 passes with my porter cable polisher + ultimate compound at 6000 rpm. The hood is baby skin smooth with very little swirls and scratches. Almost perfect. But there's very fine hairline cracks on the clear coat. I also see the same kind of cracks developing on my 4 years old headlight lenses. I'm thinking this is most likely due to the prolonged exposure to california sun.

Will the 85 compound remove these very small but very numerous scratches? If so, what's the correct procedure using my porter cable polisher?

They are spread out everywhere on the hood surface and looks like very fine and very short white lines.

Much obliged for your inputs and have a great weekend!

Ted

[J4o2el7]

I don't know much about the 85 but reading about it, seems like is is designed for a rotary tool. The cracks in the clear sound like clear coat failure, and if it's outside baking in California's sun, with no cover, and really no prior love, that might be failure. Any pictures you could post for the more experienced guys can look at. Also it has the highest cut level! So not to sure what you would use, but unless you have some serious experience with heavy cut products, I wouldn't try it. But if your set on it, use a pad that does not offer a cut. Use a polishing or finishing pad. But I would find something else to test on before laying it down on your Mercedes. Just thoughts though.

[Maruzo]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

Hi J402el7, thanks for your input. You could be right that the clear coat might be failing. But as it is right now there's no peeling or bubbling and the entire coat is still intact. The fine lines are only visible at very close inspection. They are roughly 1~2mm long, which is why i had to be looking at it 1 feet away to really see them.

As for the highest cut level, I realize this and will take precaution to just try it on an inconspicuous spot first (lower door panel perhaps). My main concern is whether I can use my PC polisher instead of a rotary tool.

I'll take a few pics and see if i can capture these little guys on camera.

Cheers!

[The Guz]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

Without seeing photos it could be a couple things. It could be RIDS (random isolated deeper scratches). If they are RIDS you can either live with them or you will have to get more aggressive. Considering this is 15 year old paint it is very possible it is clear coat failure. Especially if the car was not properly taken care of with a coat of wax. The typical steps for a full correction are wash, clay, compound, polish and wax. I would go with either M205 or ultimate polish to follow up UC to refine the finish. I highly recommend you watch some of the videos on this forum and on youtube to understand the proper technique to use a DA polisher.

From personal experience I use a PC7424XP with the following
5.5" flat lake country orange cutting pad - M105 with a speed of 5 (same with UC)
5.5" flat lake country white polishing pad - M205 with a speed of 4-5 (same with UP)

[Maruzo]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

Without seeing photos it could be a couple things. It could be RIDS (random isolated deeper scratches). If they are RIDS you can either live with them or you will have to get more aggressive. Considering this is 15 year old paint it is very possible it is clear coat failure. Especially if the car was not properly taken care of with a coat of wax. The typical steps for a full correction are wash, clay, compound, polish and wax. I would go with either M205 or ultimate polish to follow up UC to refine the finish. I highly recommend you watch some of the videos on this forum and on youtube to understand the proper technique to use a DA polisher.

From personal experience I use a PC7424XP with the following
5.5" flat lake country orange cutting pad - M105 with a speed of 5 (same with UC)
5.5" flat lake country white polishing pad - M205 with a speed of 4-5 (same with UP)

I use the yellow cutting pad from lake country + UC with speeds of 5 ~ 6. I usually wet the pad with detailing spray and then squirt paste onto the pad. Lightly pad the paste over the treatment area and spread the paste with PC with 2000 rpm. Once evenly spread I give it 2 passes with speeds of 5 or 6.

Questions on the diminishing abrasive property of M85: how does it differ from M105? Is M105 non-diminishing?

what kind of speed setting and pads would you recommend? Can I use the PC with a yellow cutting pad and M85? If yes what's the ideal speed setting? How do I avoid scouring the paint with M85? Do I need to follow with M205 after using M85 to remove the swirls created by M85 application?

Using a rotary buffer, what's a typical speed setting recommended for M85?

I only have a PC for buffing, really don't want to invest on another buffer, since i'll have to learn how to use another type of equipment.

[The Guz]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

If you have never used a rotary then stick with a DA. You can accomplish a lot with a DA. Sometimes we have to live with the defects. I'm not sure which yellow pad you are using from lake country but if it is the one that I am thinking of, it is the most aggressive pad. I would either use UC with a lake country orange cutting pad or with a Meguiar's yellow polishing pad. You may be seeing marring on the paint as well. I would definitely use either M205 or ultimate polish. I would send back that bottle of M85. It's for rotary use only. Every paint is different so speeds on the PC are not the same. A test spot will tell you a lot about how the paint is reacting and what you need.

Here are a couple links that are good reads.

Read post #15

http://www.meguiarsonline.com/forums/showthread.php?40247-M105-vs-M85-vs-M95-vs-UC/page2&highlight=SMAT

A good read on the difference between SAMT and DAT

http://www.autogeekonline.net/forum/hot-topics-frequently-asked-questions/23561-smat-pack-everything-you-ever-wanted-know-about-meguiar-s-smat-products.html

http://www.meguiarsonline.com/forums...t-surprise-you!

Good info on priming your pad

http://www.meguiarsonline.com/forums/showthread.php?31568-A-look-into-Pad-Priming-The-Kevin-Brown-Method

http://www.meguiarsonline.com/forums/showthread.php?42806-Meguiar-s-Quik-Tips-Video-Series-Using-the-G110v2-Dual-Action-Polisher

[Maruzo]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

Thanks very much for the informative reads and tips, Guz. I'll probably stick with my PC and keep using UC as well. I might invest on M205 as a follow up after the UC. I do have the orange pad and will probably start using it soon. The yellow pad is on its last leg with the black backing foam breaking apart on the edges.


There's no paint marring on the car surface so far, but i'll leave the yellow pad for emergency uses (coupled with M105?)

[Maruzo]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

Thanks very much for the informative reads and tips, Guz. I'll probably stick with my PC and keep using UC as well. I might invest on M205 as a follow up after the UC. I do have the orange pad and will probably start using it soon. The yellow pad is on its last leg with the black backing foam breaking apart on the edges.

There's no paint marring on the car surface so far, but i'll leave the yellow pad for emergency uses (coupled with M105?)

[Maruzo]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

http://tinypic.com/usermedia.php?uo=fNkd6hpTbcOB3Py5X7yql4h4l5k2TGxc#.U5QHCXKwKiE

[The Guz]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

This should help you out.

[Maruzo]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

cool. thanks!! Any idea if this is a clear coat failure? Will it get worse?

[Michael Stoops]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

M85 is a very aggressive diminishing abrasive compound that really should only be used with a rotary buffer. It needs the shear forces and heat of a rotary to properly break down these abrasives, and a DA won't do that sufficiently. The net result is usually a scouring of the paint. M105 is a far better choice for heavier cutting on a DA, especially when coupled with microfiber pads instead of foam.

That said, it looks like you've got the start of paint "checking" here, usually caused by a combination of heat exposure and age. Unfortunately, this condition can't be repaired with traditional buffing methods as they are very deep. Even wet sanding usually won't fix it as it's a condition so pervasive in the paint the new problems are developing that you can't even see yet. The only real, true fix is to repaint the effected panels. Not our favorite thing to tell people, but unfortunately not everything can be fixed with a buffer and compound.

[Maruzo]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

Hi Michael. Thanks for the explanation on the M85 property. I have decided to get M105 + M205 so I can continue to utilize my DA polisher.

As for my car. I guess black paint + high engine heat + California sun is simply a paint failure waiting to happen. Given what i have now on the paint surface, do you know what's to come next?

I try to park it in the shade when I'm at work, but there's a 4 hour window from 11am to 3 am where my car will be exposed to the sun. I use nxt 2.0 and gold class paste wax every couple of months, and every month or two I'll keep this car in the garage for a month long hiatus. But there's not much else I can do since it's primary duty is still as a daily driver.

Using M105 + my porter cable 7724xp, can you recommend a microfiber pad that'll fit on my equipment?

[The Guz]

Re: Meguiar's 85 compound, how to use it with a porter cable 7424xp?

There is a thread over on autogeek about clear coat cracking which is what you have and what Michael has explained. I could not find the thread. As Michael stated the only fix is a repaint.

Since you already used UC on the hood I would follow up with M205 and then wax. I saw your other photos and I would first do a test spot with M205 and a polishing pad. If this removes the swirls then continue around the car and then wax. If you need more correction then you can move to UC or M105, M205 and wax. I also recommend you pick up a spray wax to maintain your wax until the next time.

This would be my recommendation for the DAMF system to have. Comes with everything you need.

http://www.meguiars.com/en/professional/products/dmckit5-da-microfiber-correction-system-kit-5/