"Cover Passes" explanation please..

[Mary S]

Re: "Cover Passes" explanation please..

Mary S, try googling- site:meguiarsonline.com "cover passes"

Then click on, learning how to use the rotary buffer. Scroll down till you see the "cover passes" in bold. Was randomly browsing through the forum insearch of stuff to learn. Came across that thread and wondered, how come I never did cover passes?

Okay, I found this in an article by Mike Phillips:

"After you have worked each quadrant or section over the entire panel, then do what's called a few "Cover Passes", this is where you use the rotary buffer to now buff the entire panel to more or less tie all your work together, that is to give the finish a uniform, level surface with equality in appearance over the entire panel. In most cases the paint is going to have light swirls or haze after this step but that's okay as the next step will remove most of these."

I think I get it now. Suppose you are doing the hood, working in 2x2 sections, or maybe 4 quadrants of the whole hood. So you are working say with 83, your first compound/polish, and you are done with the 4 quadrants. He is saying now that you have finished pieces of a patchwork quilt, now make passes across the entirety of the hood, left to right, up and down, so as to give the panel uniformity and not make it obvious that it was done in sections. I think that's what he means. I have no idea how intently he pays attention to this step but I would assume it is a fairly light couple of passes.

As far as product to use, I would assume the same one you did the sections with, 83 in this example.

[Lasthope05]

Re: "Cover Passes" explanation please..

Mary S, try googling- site:meguiarsonline.com "cover passes"

Then click on, learning how to use the rotary buffer. Scroll down till you see the "cover passes" in bold. Was randomly browsing through the forum insearch of stuff to learn. Came across that thread and wondered, how come I never did cover passes?

You are misinterpreting the content. Cover passes does not mean to dry buff the panel. What Mike P. meant in a cover pass is tying together all the individual sections you worked together. An example of this is; you section out a fender in to two parts and you polish one side first and then the other. The next step is a "cover pass" meaning you polish the same panel again but instead of braking it down into to two sections you work the entire panel to blend the two halfs together.

In reality there is no need for "cover passes." When you're polishing sections all you need to do is slightly over lap the last section.

If you work one panel to perfection and move on to the next what is the point in a cover pass when each section you finish is perfect? How you blend two panels that are perfectly marr free is beyond me.

[Perfectshine]

Re: "Cover Passes" explanation please..

Mary S, He also mentioned it et a later paragraph. That is why we need Mike Phillips to clarify or even write an article more on this step. I'm interested!

[Michael Stoops]

Re: "Cover Passes" explanation please..

He is saying now that you have finished pieces of a patchwork quilt, now make passes across the entirety of the hood, left to right, up and down, so as to give the panel uniformity and not make it obvious that it was done in sections. I think that's what he means. I have no idea how intently he pays attention to this step but I would assume it is a fairly light couple of passes.

As far as product to use, I would assume the same one you did the sections with, 83 in this example.

Yes, that is exactly right. You should be using the same product as you did on each of your individual sections, or perhaps even a step down product, but certainly not just a dry (or almost dry) pad.

Still, if you properly overlap your passes onto the previous section, you will greatly minimize the risk of any sort of patchwork appearance.

Hopefully this graphic (crude and quickly thrown together as it is) will help to visualize this a bit more. What's important to keep in mind so as to avoid this is to confine your work area and work a diminishing abrasive through it as uniformly as possible. SMAT products help to avoid a lot of this simply by virtue of the behavior of the abrasives in those products.



As you can see, just working a diminishing abrasive from, in this case, top to bottom will give you more cut at the top and less at the bottom of your work space. You need to work more uniformly to achieve a more uniform cut. The more uniformly you work, the less you need to worry about cover passes.

Again, using SMAT products almost eliminates this completely.

[Mary S]

Re: "Cover Passes" explanation please..

Thanks, Michael. That makes sense why this is more relevant using the DMAT, and why we don't hear so much about it with SMAT.

Shineshine, you might bring your questions over to Mike Phillips on the autogeeks.net site. I had the impression that their flagship compounding products still use DMAT so they may still be doing this, and he could give you an updated explanation.

[Tim Lingor]

Re: "Cover Passes" explanation please..

Hey,

Let's see if I can clear this up...

Usually when machine buffing a panel, we break the panels up into sections of 18"x18" or so in order to concentrate the buffing in that one area/section of the panel. Then after completing that section, you do the same for the next section.

Cover Passes is when you are finished buffing all the sections, on say the hood, and now want to tie them all in together. To do this, it can be accomplished in a couple of ways. Let's say the hood was broken into 4 sections, and now you want to tie the sections together, many people will now on the one side of the hood do cover passes over the 2 sections on that side at the same time Ie. start at the front of the hood and buff both sections in large side to side motions. In essence, this may help remove any slight difference between the sections. Usually you use a little more compound (usually a milder compound but the same compound can be used) or if the pad is still wet with product and the residue on the panel is not dry, you can lighten your pressure and speed with the rotary to bring the sections all together with a uniform look. Never dry buff a panel!

Now with that said, in most cases, if you have overlapped the sections while buffing, you probably would not see anything different. In fact, going over a perfectly polished panel may re-introduce marring back into the panel.

I hope that helps!

Tim

[Perfectshine]

Re: "Cover Passes" explanation please..

Thanks everyone for the detail explanation.

Tim, that's what I understood as well. Say for the hood, one huge round of overlapping after the cleaning stage to tie down the sections using a (still) saturated pad, then off to the next step which is the polishing stage where it'll get rid of the marrs. Somehow I do think it benefit as stated that it'll ensure uniform surface.. I guess I have to keep on doing this cover passes after every stage until LSP. Let me give it a go and will post the results in a few days.

[Mary S]

Re: "Cover Passes" explanation please..

In fact, going over a perfectly polished panel may re-introduce marring back into the panel.

Mike said about the same thing in his article:

"In most cases the paint is going to have light swirls or haze after this step but that's okay as the next step will remove most of these."

I am glad you brought this up, shineshine, because all I have seen demos of, and all I have practiced on, is one area of a hood at a time, not putting the whole thing together (well at least Buffing with Confidence you see him do other parts of the car), and I had never heard the term cover pass before, but now here almost all of us have the SMAT compounds and of course this doesn't apply. But if we were to choose 83 or 80, as you are, this is important to know.

I would like to see a demo of how Mike Phillips does this just to get an idea how quickly he moves the buffer, how much product he uses, which product, how much pressure, how long it takes, any reapplications of product, all that sort of thing. Now that I understand the theory, some the practical aspect is missing for me. It seems that if he is just applying 83 and going over the hood with 1 application, some of the explanation Michael Stoops showed in his diagram might apply to cause the results to be uneven because of the DAT; well, maybe this is what he means by the marring being introduced, especially since each section will not be receiving the full effect of the diminished abrasives.

This makes me all the more appreciative of the SMAT technology, which has been around long before I was here.

[Perfectshine]

Re: "Cover Passes" explanation please..

Mary S, The only SMAT products theyre seling here are the consumer's UC and swirlX , loved them, but i still do need that cutting power from a rotary and for time. For some reason the dealer stop selling the professional line products. Bought the big bottles of 83,80 & 21 four years back and i still have half in 83 & 80, but finished the 21..I would really be greatful if they can just get me the small bottle's of 105 & 205 though..

I would also love to see a video demo like you said, and he must have mentioned cover passes for a reason.

[Mary S]

Re: "Cover Passes" explanation please..

Mary S, The only SMAT products theyre seling here are the consumer's UC and swirlX , loved them, but i still do need that cutting power from a rotary and for time. For some reason the dealer stop selling the professional line products. Bought the big bottles of 83,80 & 21 four years back and i still have half in 83 & 80, but finished the 21..I would really be greatful if they can just get me the small bottle's of 105 & 205 though..

If you're in the continental US, ADS has both an 8 oz size and a 12 oz size.

http://www.autodetailingsolutions.net/m20508.html

http://www.autodetailingsolutions.net/m10508.html

I didn't see the 8-ounce sizes in the Meguiars Direct catalog, but I bet if you called them they have it, and they do ship this internationally as I understand.

It occurred to me, we are supposed to use the least aggressive method for correcting, maybe 83 will work and is less aggressive than 105, then we should consider using it. But for the cover pass, then you could use 205 because the properties of 205 for a cover pass would be better and would not introduce any new marring or hazing like 83 would. Older technology meets new.

[Perfectshine]

Re: "Cover Passes" explanation please..

I didn't see the 8-ounce sizes in the Meguiars Direct catalog, but I bet if you called them they have it, and they do ship this internationally as I understand.

Will browse through this, thanks!

Older technology meets new.

you bet!

[Mary S]

Re: "Cover Passes" explanation please..

Mary S, The only SMAT products theyre seling here are the consumer's UC and swirlX , loved them, but i still do need that cutting power from a rotary and for time.

Shineshine, have you tried UC with the rotary? When I was learning the rotary, Michael Stoops told me that people were having success with UC on the rotary. I tried it (on my test hood) up until I got my order of the 105, and I didn't have any problems. I got good results. You might have to test it for each situation, but this is an off-label use that appears to work sometimes, so if you haven't tried it, it might be worth trying. I don't recall trying SwirlX, that one as I recall is rather thick and might not work.

[Michael Stoops]

Re: "Cover Passes" explanation please..

As Mary points out, UC has been known to work well with a rotary, but as she also mentions, this product was not developed with rotary work in mind so we can't officially recommend it this way. What that really means is that under certain circumstances UC may not behave the way you expect, or might like, it to when used outside it's design parameters. You won't hurt anything using it this way, but we can't say it's a "proven" rotary product.

Remember, UC was formulated for general consumer use, and that very rarely means a rotary user.

[Perfectshine]

Re: "Cover Passes" explanation please..

Yup, tried UC with the rotary before on a car(sorry I had no choice for a more aggresive product). I didn't take note though, as I wasn't planning to stay with that process for long in fear of something bad will happen with the non recommended. But I do remember the UC dries up faster with the rotary, maybe its just me and my process. if we can get this guys who had success in using UC with rotary to share their steps with us, that'd be great!! Anyone know a link to any thread on this topic?

SwirlX really kicked up the gloss btw.. and squeezing it out of the bottle is a PITA most of the time.. that's how thick it is

[Michael Stoops]

Re: "Cover Passes" explanation please..

What you've seen when using UC on the rotary is why we don't officially recommend it be used that way. It may very well be that the paint itself is playing a large role in the way UC is behaving for you via rotary. You might want to experiment a bit with quantity of product, speed, and pad choice. In some cases a small amount of product at a little bit higher speed will work better then a lot of product and slower speed, and in some cases it's going to be the other way around.