FG400 How long to break it down

allenk4

allenk4

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I know there are lots of variables, such as machine speed, type of pad, downward pressure...

Wondering, ballpark, how many minutes it takes to break up the agglomerated particles?

The main reason I ask is the 1" per second arm speed discussion...

If you are working a 2'x2' section; isn't the compound broken down by the time you get to the bottom corner of the 1st pass?

I would think this would cause the upper left area to receive a lot more cut than the lower right area...is that makes sense

Other questions I have are:

What is the real effect of spreading the polish over the panel at lower speed before raising the speed for the working cycle? Is it the polish that is trapped under the pad that is doing the work and the polish that was spread on the panel just getting whisked away by outer edge of the pad, because visually, that is what I see when the pad is flat to the surface of the paint.

Should a faster arm speed be used with SMAT than with DAT to achieve uniform cutting on a section?
 
I usually do a medium speed (I never go by the 1" per second stuff). And depending on pad, make 3-6 passes. If Im using MF cutting pads, seems I can do in 3 passes what it takes me 6 to do with a foam pad.
 
Generally, I'll give too-few passes and then work my way-up to more passes eachtime inspecting the results. Therefore, I know when I am not making enough passes and know when I am making too many passes.
 
The polish you spread out should be getting picked up by the pad
 
Spreading the polish at low speed does just that, spreads it out so the pad is not overloaded at the start and full of spent polish at the end of the section. In theory, you get a more uniform result.

4 passes with FG400 is about my minimum, usually 5 passes are necessary unless the paint is very hard. I have determined this based on the amount of DA haze after 4 passes, some times it's fine and sometimes not.

I'm sure you've also seen polish being pulled to the center of the pad
 
I have seen polish and the lubricants in it appear to move towards the center of the pad, but that doesn't even make sense

If the pad is rotating....shouldn't centripetal force move the abrasives and liquid away from the center of the pad?

If you lift the pad off the surface while it is running, the polish definitely goes outward. Why would it be different with the pad on the paint?

Maybe the center of the pad stays wetter that the edge, because the abrasives and their liquid carrier is trapped there

I would also think that the outer area of the pad is more susceptible to drying out

I can visualize how the pad on a rotary could pick-up polish that was spread ay the beginning if it was held at a slight angle, similar to picking up a bead of polish
 
Really, I am looking for an increment of time...

Say, FG400 will reliably breakdown to its smallest abrasive (unagglomorated) particle size in 90 seconds when using moderate downward pressure on speed 4 with a DA polisher

What is your best guess?
 
The compound/ polish in the center of the pad isn't being subjected to as much centrifugal force as compared to the outer edges of the pad. So yeah, the outside of the pad is going to dry out faster because the outside is moving faster and letting go of more media than the inside is "able" to. Just an off-topic post, don't mind me
 
Belphegor said:
The compound/ polish in the center of the pad isn't being subjected to as much centrifugal force as compared to the outer edges of the pad. So yeah, the outside of the pad is going to dry out faster because the outside is moving faster and letting go of more media than the inside is "able" to. Just an off-topic post, don't mind me
Click to expand...

Makes perfect sense

Have you ever seen or heard an explanation of exactly how the abrasives would work their way toward the center of the pad?
 
I should have used centrifugal instead of centripetal in a previous post...hopefully, it did not confuse my question
 
Nope, it's crazy how much can build up there though! I think it's not necessarily that the center "attracts" more media than the rest of the pad during polishing, but that any media that was there when polishing started and any that was picked up during passing over fresh media just tends to stay there. I would appreciate a more knowledgeable/ technical explanation if anyone has one to offer.
 
I've never used FG 400, but to me - the polish is broken down when it's broken down. I'm shooting for the pad to still feel "wet" when I'm done, the polish to almost be invisible on the paint, and no blob of polish left on the paint where the center of the pad was when you pull the machine off.

If you achieve those 3 things - the polish is worked just "long enough" IMHO.

1" per second is really slow...But, likely the correct speed of your going after noticeable defects for the first few passes.

Does it really matter if you go 1" per second and do 3 passes; or 2" per second and do 6 passes - probably not much. I usually move the machine pretty slow - but only do 4 passes.

If you use polymer heavy type polishes; like Optimum or Rupes - they tend not to gum up and migrate to the center of the pad - like Menz polishes do. Also, I've noticed Rupe's pads for whatever reason don't really gum up or migrate product to the center; unlike other pads.
 
I remember a post from Mike Phillips where he just put 3 dollops of polish on a rupes pad on a 15 or 21 then turned it on. Then he had a pic of how the polish migrated, I'm forgetting what it looked like though. That may reveal a bit more of what is going on; Paging Mike Phillips....
 
swanicyouth said:
I've never used FG 400, but to me - the polish is broken down when it's broken down. I'm shooting for the pad to still feel "wet" when I'm done, the polish to almost be invisible on the paint, and no blob of polish left on the paint where the center of the pad was when you pull the machine off.

If you achieve those 3 things - the polish is worked just "long enough" IMHO.

1" per second is really slow...But, likely the correct speed of your going after noticeable defects for the first few passes.

Does it really matter if you go 1" per second and do 3 passes; or 2" per second and do 6 passes - probably not much. I usually move the machine pretty slow - but only do 4 passes.

If you use polymer heavy type polishes; like Optimum or Rupes - they tend not to gum up and migrate to the center of the pad - like Menz polishes do. Also, I've noticed Rupe's pads for whatever reason don't really gum up or migrate product to the center; unlike other pads.
Click to expand...

Excellent advise and post.
I haven't used the other as I've got all Menz and Wolfgang, Blackfire polishes. But I defintitely notice the gumming mentioned, that's when I clean the pad and hit with a light spritz of detail spray. When it gums up again I go to a fresh pad. FG400 Rocks!
 
FG400 is a super concentrated product. I typically use 2 pea size drops for each section and it takes a long while for it to break down. Especially if you use to much product, it seems like you can buff it forever. I prefer to make 8 pass's. NO less.

If your working on hard paint you wont notice this as bad as if you were working on soft paint. If you cut the buffing cycle short on soft paint you will see what im talking about. it will give you DA haze and holigrams at the same time. For that reason I typically use very little product and at a minimum make 8 pass's.

If you plan on following up with a second step its not as critical to make 8 pass's. you can short buff (4 pass's) the cycle and move on knowing that you will clean it up with the second step. It does cut fast on the first few pass's.

regarding spreading the polish out on the panel first. I do not believe its at all necessary with a primed pad. Its serves no mechanical purpose. But it does help in visually seeing what your doing and helps keep your work area the intended size. I'm sure you know its easy to get carried away and intend on polishing a 2 X 2 area, but actually wind up going way past that unless you step back (mentally) to remind yourself to stay in the area you began with.
 
RevitalizeAutoSpa said:
DAT versus SMAT figures pretty heavily into this discussion.

http://www.autogeekonline.net/forum...anted-know-about-meguiar-s-smat-products.html
Click to expand...


Good link, thanks

The explanation I got from Mike Stoops is, paraphrasing, that DAT is like a bunch of SMAT abrasive particles bound together to form a larger particle which will cut better

For example it would be like bonding together 5 particles of M205 to make a particle the size of one particle of M105. During the polishing cycle the 5 particles are gradually broken apart...eventually they are the size of one particle of M205.

This allows the product to cut like M105 at the beginning and finish like M205


I know these two are SMAT, but I thought it made the concept easier to understand
 
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