Plastic Bag Test - Do You Really Want To Know?

I don't do ANY polishing until after the paint has passed the bag test.

I always start with a wash, dry, then iron-X, then a complete claying. After that the paint should always be smooth enough to pass the bag test.

Then you may polish the paint if the finish requires it. Otherwise your pad is probably just gliding over the embedded crud and isn't even touching the paint at first.

So why polish crud? Get the paint clean enough to start with to actually be polishing the surface of the paint.
 
oldmodman said:
I don't do ANY polishing until after the paint has passed the bag test.

I always start with a wash, dry, then iron-X, then a complete claying. After that the paint should always be smooth enough to pass the bag test.

Then you may polish the paint if the finish requires it. Otherwise your pad is probably just gliding over the embedded crud and isn't even touching the paint at first.

So why polish crud? Get the paint clean enough to start with to actually be polishing the surface of the paint.
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Wow, that makes sooo much sense. What clay are you using because the Wolfgang clay doesn't cut it? Gets most of the crud, but not all. I even did a second clay with the Pinnacle fine clay bar and the paint still couldn't pass the bag test. I'm hoping the Clay Magic Blue is the ticket and I can eliminate the cleansing stage altogether. If not, think I'll change up my process a bit and cleanse the paint before I polish - it's so logical once you think about it. Though I have to say that polishing helped to get rid of a little of the contamination that the clay process left behind - though not completely.

Thanks for the suggestion oldmodman!
 
addysdaddy said:
because the Wolfgang clay doesn't cut it? Gets most of the crud, but not all.
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Trying several clays is not the answer. Get some IronX spray and go around your car with the stuff, let it sit for 2 or 3 minutes and rinse completely... NOW you're ready for claying..

The IronX will take care of 90% of the crud.. The clay step will be 1000x easier!
 
bmwgalore said:
Trying several clays is not the answer. Get some IronX spray and go around your car with the stuff, let it sit for 2 or 3 minutes and rinse completely... NOW you're ready for claying..

The IronX will take care of 90% of the crud.. The clay step will be 1000x easier!
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Been there done that as outlined in my original post - it helps but doesn't eliminate all the contamination.
 
bmwgalore said:
Ignorance is Bliss, that's my motto for everything in life, except cars...
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Too bad, then, if you, indeed, must live your life in such a manner. :(

IMO...Ye olde English poet Thomas Gray's inclusion of the word: where...in his: "Ode on a Distant Prospect of Eton College"...established an important "ignorance-qualification" difference; that is...
It isn't best to be blissfully-ignorant, than wise, at all times...Just when a person's fate is being referenced!

Afterall, he was just revisiting his time spent when, and as, a youth.

"...Yet ah! why should they know their fate?
Since sorrow never comes too late,
And happiness too swiftly flies.
Thought would destroy their paradise.
No more; where ignorance is bliss,
'Tis folly to be wise."

:)

Bob
 
Anyone have an experience with the Wolf decon gel? Iron X doesn't seem to getting the job done for me and wondering if there's an alternative out there. Besides, really hate the foul order from Iron X.
 
addysdaddy said:
Been there done that as outlined in my original post - it helps but doesn't eliminate all the contamination.
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Did you agitate with a brush or sponge?
I've never seen anything that IronX or Trix wouldn't remove..
 
Working in full shade and late in the day, I sprayed the entire vehicle and took a Schmitt (that I decided to transition for just this purpose) and rubbed the Iron X in all over the car. Let it dwell for 10 minutes per a timer (haha) and rinsed off. I can only assume that whatever is stuck to the paint is not iron based.
 
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Can somebody explain to me the science behind the plastic bag test?

How does the bag enable you to feel the dirt better than your bare hand?

Always having been skeptical, I can't help but wonder that perhaps it works on some
unknown principle and is a diabolical plot by clay manufacturers to sell clay. :D
 
oldgeek said:
Can somebody explain to me the science behind the plastic bag test?

How does the bag enable you to feel the dirt better than your bare hand?

Always having been skeptical, I can't help but wonder that perhaps it works on some
unknown principle and is a diabolical plot by clay manufacturers to sell clay. :D
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Not sure of the science behind it but scroll up and look at the link provided on how to clay and use the plastic bag. My best recommendation is wash your car, feel the paint with ur hand and then try the bag test. There will be no denying the difference. Again now that your aware of the contamination you'll need to decide on whether to ignore it or work to get rid of it.
 
When using the baggie for a test you will find the thinner plastic found on a baggie with a fold over lid instead of a slider or zip-lock works better at letting you feel the contaminents.The clear wraper off of a pack of smokes will also work. As to why the baggie works better then just a bare hand is only a guess on my part . The plastic seems to amplify the contaminents IMO.
 
The fingertips have the highest concentration of nerve ending in the human body (that's why paper cuts on the fingers hurt so bad, but a cut on the thights barely hurts at all), so when you run your finger along the panels you can feel all the imperfections on the paint.

But since car paint is sooo thin, the plastic bag acts as a resonator between the nerve endings and the imperfection on the paint.

Not just paint, it doubles as an "sensory amplifier" for everything else too.
 
SO...bmwgalore, are you saying that, perhaps, the plastic "catches" on the contaminants and mutes the normal paint irregularities, thus, effectively amplifying the contaminants to your nerves. Kinda like a hearing aid amplifies the sounds you want to hear while muting the background noise...

I'll buy that. :-)
 
oldgeek said:
SO...bmwgalore, are you saying that, perhaps, the plastic "catches" on the contaminants and mutes the normal paint irregularities, thus, effectively amplifying the contaminants to your nerves. Kinda like a hearing aid amplifies the sounds you want to hear while muting the background noise...

I'll buy that. :-)
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No, it amplifies the sensory fell in the brain (where it is located in first place), not in the paint.

Stroke your hair with bare fingers, now do the same with a thin zip-lock bag... There are no imperfections on your hair, but now you can really feel the texture of your hair.
 
So let me get this straight. You put a plastic baggie on your hand and rub it across the paint to determine if you should rub a claybar across the paint?

This makes absolutely no sense to me
 
So I have to ask, is the paint supposed to feel glass smooth with the baggy test after you clay? Or you just shouldn't feel any grit? On multiple vehicles now I've tried a baggy before & after (admittedly the thicker ziploc sandwich baggy type) and after vigorously claying an area with Mother's gold clay and clay ratio ONR (or even the Mother's QD that comes in the clay kit) the paint still feels rough to me. Not gritty, just rough. I don't know if I'm just feeling the orange peel or if it's actual contaminants. If I rubbed any more vigorously/longer my shoulder would fall apart. Maybe I am getting the paint too wet?
 
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