A new perspective on paint defect return (interesting)

[ABQDetailer]

So as I'm understanding this should be our prep process:



Wash

Clay (w/lube)

Prepsol/Dawn/APC/etc (aka deep cleaning "wash")

Compound/Polish



The deep cleaning wash is needed to remove anything left from the clay step that could adversely affect the Compounding/Polishing step, correct? Otherwise clay lubes and residual waxes/sealants are working AGAINST our paint reconditioning work?



If the above is true then one could also argue that the oils/mineral spirits in compounds/polishes could also be having an adverse affect on the next polishing step. So we should be doing a prepsol step in between every polishing step? I guess if you were using very similar products then it wouldn't matter as much?



Also I was thinking yesterday as I bought a new bottle of Wax and Grease remover: Wouldn't it be beneficial to use a prepsol type product BEFORE claying? I would assume something more intrusive like prepsol can only help remove contaminants that you are trying to remove via clay bar.



To take it to a further extreme: Could one totally eliminate claying by doing a prepsol step instead? Or are there still contaminants left behind that only claying can remove? When prepping a surface for refinishing I've never heard of clay bar being used-only prepsol + tack cloth types of prep-and I would assume claying would be mandatory in the paint refinshing industry if it were the only way to truely prep a panel (not just for removing overspray and for paint reconditioning prep ).



Just some random thoughts here from a hobbiest...

 

[imported_rydawg1]

You need to clay before prepsol. Prepsol will not remove debris from paint as good as clay. Prepsol will not remove embedded silicon from paint. Prepsol will not even remove all polishing lubes from paint, especially on newer factory paints. I always use 91% straight IPA for proper inspection.

 

[imported_rydawg1]

Usually non-metallics have a higher coefficient of thermal expansion (CTE) than metals, and since a piece of sheetmetal like a car hood is much, much larger in the lateral dimensions than it is in thickness, so yes, the paint could be stretched, thinner if the metal is hot, but the paint will also be getting thicker (as the metal will be) as it gets hot.



The thing is if the steel (using a steel hood example) is 4' wide but only .030 thick, and it expands 5%, it will grow only .0015 in thickness, but .200 in width. For whatever that is worth, probably nothing.

Metallics usually do not have this problem. The metallics hold the clear like a tight bond.



Blacks are always the number one issue as I am sure some of you already have experienced this. Reds can also be a pain, but not as bad as black. It has nothing to do with it just being black and you just notice more.



I have spent hundreds if not thousands of hours examining problem paints on different colors and blacks always seem to absorb silicones like a magnet. I think with it being black, that it gets so hot siiting in the sun that everything just melts right into the paint.



Then you have your soft paints like Honda, Porsche, etc, that everything just sinks right into the paint. We all know what a black Honda looks like when poor dealer prep and products are used. A year later it starts cracking the paint, especially the hood where it gets blasted with the engine heat also. If these cars get silicone latched into the paint, it is all over. You start getting those tiny little white specs in the paint and some will even get these white/gray patchy blotches after a few years. After 3 years, the paint starts to have the hazy look that looks like scaling which I call crazing. Crazing is the form of dried up silicone ready to release from the paint. Sometimes it takes a thin layer of the paint with it leaving behind premature paint failure.



Hard paints like some BMW's, C5 Vettes, Audi's, etc. are much more forgiving due to the harder clears and silicone usually comes off in a few hours. I really wish all paints were like this.

 

[Mobilejay]

Thanks for the post, I learned a lot.

My question is do we have to polish outside once the paint is hot as hell? If the paint is going to "swell" after it is sitting outside(after you polished) and it is going to show defects do we have to do it outside under the sun when its already expanded? Am I making sense?

 

[DSVWGLI]

So by leaving that car in the sun, you "expanded" the paint, opening up the defects you previously couldn't see?

So, assuming we have striped the paint of all polymers & silicons, if heating up paint reveals defects that are not seen when the paint is cooler, then heating up the paint when we are compounding/polishing to remove defects would be ideal. If no defects are present after that process there should be no defects returning regardless of the molecular state the paint is in. Correct?

 

[Setec Astronomy]

Metallics usually do not have this problem. The metallics hold the clear like a tight bond.

Sorry, I was using different terminologies...when I said non-metallics I was referring to materials which are not metals, such as plastics, paint, etc., not paint types. Didn't occur to me that was going to cause confusion

 

[Setec Astronomy]

So, assuming we have striped the paint of all polymers & silicons, if heating up paint reveals defects that are not seen when the paint is cooler, then heating up the paint when we are compounding/polishing to remove defects would be ideal. If no defects are present after that process there should be no defects returning regardless of the molecular state the paint is in. Correct?

You're askin' me?? I dunno, sounds right

 

[imported_rydawg1]

Thanks for the post, I learned a lot.

My question is do we have to polish outside once the paint is hot as hell? If the paint is going to "swell" after it is sitting outside(after you polished) and it is going to show defects do we have to do it outside under the sun when its already expanded? Am I making sense?

Polishing in the hot sun is not good and it can dry out the compounds and even cause unbalanced breakdown. Always polish in the shade if you can. Not many cars will have issues with silicone.



An IPA wipedown before will always help remove some of the stuff on the top layer.

 

[DSVWGLI]

I have spent hundreds if not thousands of hours examining problem paints on different colors and blacks always seem to absorb silicones like a magnet. I think with it being black, that it gets so hot siiting in the sun that everything just melts right into the paint.

Can the molecular structure of paint change that much when heated, that another substance (ie:silicone) can be absorbed into it? Wouldn't the molecular structure of both have to change dramatically more than just being heated up by the suns rays? If this is happening, aren't these two substances now becoming one substance ? Perhaps the silicons and polymers are just settling into the porous surface of the paint and not penetrating on a molecular level :think:. Stripping all of the silicons and or polymers out of the pores of the paint will be more difficult than what is just on the surface (not in the pours) would it not?

 

[imported_rydawg1]

Sorry, I was using different terminologies...when I said non-metallics I was referring to materials which are not metals, such as plastics, paint, etc., not paint types. Didn't occur to me that was going to cause confusion

I was thinking that, but you also reminded me of the metallics not being a problem too.:dance



Plastics, fiberglass, aluminum still have the issue, but not as bad. It all depends on the paint type though. Although sometimes they do need heat to cook the silicones out and working on panels like this do not heat up like metal, so it can take longer to polish them out.



But if you get a black fiberglass hood that has has silicone set in from the hot sun and the heat from the engine then it can be a total pain in the butt to polish out. I have been playing with some addatives to keep the abrasives suspended longer so they do not break down prematurely. This allows the polish to work longer (particle size) and to allow the heat to build up to help burn out whetever could be in the paint.



Take for example: A gray Porsche can polish out quick for the most part because the metal heats up quick, but the bumpers can take a lot longer to polish out because the plastic does not heat up as fast.



I think it's time for me to design my own compounds and polishes.:hm

 

[Setec Astronomy]

Sorry, I'm really being unclear, I guess, when I said non-metaillics, what I was really referring to was the difference in CTE between the (non-metal) paint and the metal, not about different substrates. "Plastics" typically have a much higher CTE than "metal". I was responding to the remarks about the metal growing and "stretching" the paint, and my point was really that the paint should grow more than the metal.



I can't really speak to the issues of the silicone absorbtion, I was just throwing my $.02 in on the stretching.

 

[imported_rydawg1]

Can the molecular structure of paint change that much when heated, that another substance (ie:silicone) can be absorbed into it? Wouldn't the molecular structure of both have to change dramatically more than just being heated up by the suns rays? If this is happening, aren't these two substances now becoming one substance ? Perhaps the silicons and polymers are just settling into the porous surface of the paint and not penetrating on a molecular level :think:. Stripping all of the silicons and or polymers out of the pores of the paint will be more difficult than what is just on the surface (not in the pours) would it not?

I am not a chemist:grinno:but I would say yes... It is very confusing and frustrating for some. I always use 91% IPA heavily right after each panel polished so the swelling can't take place. I always wash pads every panel too if I know there is still silicone present, so it does not spread and get forced in (cross contamination) from the heat.



Some paints the silicones will come right out. Some paints will take 20-40 hours of serious polishing to remove everything with heat and abrasion.



Not every product will give issues to paint.



The worst I have experienced so far removing are:



Coin or tunnel wash waxes (the worst)

Turtle wax ICE

New car sealants (dealer scams) Very bad, especially if they power buffed it deep into the paint and over worked it.

FK1 wash and wax ( It's too bad, I loved this stuff till I had to polish a few cars) Only on certain paints though.

Zymol Concours ( had tons of silicone, but came off for the most part.)



Some silicones can settle into the paint and some can sit on top.

 

[Kevin Brown]

...If these cars get silicone latched into the paint, it is all over. You start getting those tiny little white specs in the paint and some will even get these white/gray patchy blotches after a few years.

After 3 years, the paint starts to have the hazy look that looks like scaling which I call crazing. Crazing is the form of dried up silicone ready to release from the paint...

rydawg,

What you have experienced is contrary to what I know about silicones (and how they might react with paint).

I am not qualified to definitely discount your statements, though, so take my input at face value.

I'm a detailer, paint-polisher, and car enthusiast; but have no formal education in the realm of chemistry.



There's probably one or two qualified chemists around here that could offer an opinion based on substantiated testing and/or knowledge.

Maybe their training is not used in the car care industry, but similar technology must be used elsewhere.



I'm not of the opinion that silicones are a bad thing in paint care products, as I cannot recall an incident where I could definitely attribute premature paint failure to a product that used silicone in its makeup.



Most times, environmental damage, incorrectly applied cleaners (not traditional paint cleaners, either), and basic improper car care are the cause for the damage I've seen during the 24 years I've been, "Rubbin' out cars".

 

[imported_rydawg1]

Sorry, I'm really being unclear, I guess, when I said non-metaillics, what I was really referring to was the difference in CTE between the (non-metal) paint and the metal, not about different substrates. "Plastics" typically have a much higher CTE than "metal". I was responding to the remarks about the metal growing and "stretching" the paint, and my point was really that the paint should grow more than the metal.



I can't really speak to the issues of the silicone absorbtion, I was just throwing my $.02 in on the stretching.

On the stretching part...I have no clue at all. I figured you would know this:secret



I would say there is more difference between 0 - 50 degrees than 50-100 degrees. But I am just assuming.



My honest opinion, I do not think the sun is expanding the metal and making the defects come out. It's more of an outgasing issue due to solvents evaporating.



We all have to remember one thing....PAINTS WERE NOT MEANT TO BE PERFECTED LIKE THIS! The newer the paints, the worst they are getting to make perfect 100%.

 

[imported_rydawg1]

rydawg,

What you have experienced is contrary to what I know about silicones (and how they might react with paint).

I am not qualified to definitely discount your statements, though, so take my input at face value.

I'm a detailer, paint-polisher, and car enthusiast; but have no formal education in the realm of chemistry.



There's probably one or two qualified chemists around here that could offer an opinion based on substantiated testing and/or knowledge.

Maybe their training is not used in the car care industry, but similar technology must be used elsewhere.



I'm not of the opinion that silicones are a bad thing in paint care products, as I cannot recall an incident where I could definitely attribute premature paint failure to a product that used silicone in its makeup.



Most times, environmental damage, incorrectly applied cleaners (not traditional paint cleaners, either), and basic improper car care are the cause for the damage I've seen during the 24 years I've been, "Rubbin' out cars".

Your right...Silicones are in almost every sealant, wax, and qd. I think the most important factor that we all have to consider is that paint is made very poorly these days. Take a car from the 90's and you would never get issues like this at all. Ever since the VOC laws changed, some paints now have poor quality and it's not the products fault.



The paint companies really need to work on a stronger clear system for blacks.

 

[Kevin Brown]

So as I'm understanding this should be our prep process:



Wash

Clay (w/lube)

Prepsol/Dawn/APC/etc (aka deep cleaning "wash")

Compound/Polish

A wash, followed by a second cleaning step (consisting of an application of a strong detergent) would be okay, I suppose. But is it necessary? That depends.



If your goal is to clean away oxidation and/or stuck on contaminants, the wash & claying will usually suffice as a good beginning.

Afterwards, continue with your paint reconditioning.



If the surface looks good (not pasty or dry due to exposure to the elements, causing oxidation), but you wish to eliminate swirling, fine scratches, etc. (below-surface defects), you can simply abrade the surface with a paint cleaner or polish, applied any way you'd like, until the defects are eliminated.



If the wax/sealant/protectant (LSP) you last used is still protecting the paint and it is still on the surface (albeit it to a scuffed or scoured degree), but it's still durable & pliable, you could theoretically polish the defects out of the LSP before even reaching the paint, right? It depends on the depth of the defect (of course).



So, unless you plan on stripping the paint because you want to try a different LSP (and you want no other previous coating on the paint), I'd see no reason you'd want to apply detergents and/or solvents to the surface. Any time we use strong chemicals or solvents to clean paint, we cause a bit of damage. Repeat this type of cleaning too often, and the process could dry the paint (eventually leading to premature failure).

The deep cleaning wash is needed to remove anything left from the clay step that could adversely affect the Compounding/Polishing step, correct?

Otherwise clay lubes and residual waxes/sealants are working AGAINST our paint reconditioning work?

It's not generally recommended to use a clay lube that touts protective additives...

Your application of clay lube shouldn't have any effect on the paint-refinishing process.



While a VERY durable LSP can make it tough to remove paint-defects when using a fine polish, most aggressive compounds will rip right through the most durable LSP's currently available.

If the above is true, then one could also argue that the oils/mineral spirits in compounds/polishes could also be having an adverse affect on the next polishing step.

So, should we be applying a prepsol step in between every polishing step?

I guess if you were using very similar products then it wouldn't matter as much?

No!- You definitely shouldn't apply a prepsol/wax & grease remover between polishing steps.

Many prepsols DEFINITELY affect the paint to a degree that makes proper paint correction more difficult.

Did you know that some can OBVIOUSLY soften paint (On rare occasion to the point of tackiness)?

If you're going to add prepsol to your arsenal of detailing products, buy a reputable, well-respected brand. Pay a few bucks more for the good stuff.



Side note- If it's common practice for you to prepsol-wipe a paint-job that you're planning on machine-polishing, you may want to consider that, while you've removed most/all previously applied products from the surface, you may have changed the elasticity/hardness of the paint (temporarily) that you're planning on refinishing.



... And the paint swelling/filling debate would definitely apply here!

Also I was thinking yesterday (as I bought a new bottle of Wax and Grease remover):

Wouldn't it be beneficial to use a prepsol type product BEFORE claying?

I would assume something more intrusive like prepsol can only help remove contaminants that you are trying to remove via clay bar.

As Mike Phillips over at MOL always points out... "Use the least aggressive method, first!"

Keep the solvents away from the paint as much as possible. While they're a necessary-evil, there's no need to apply them unless you've got a solvent-based contaminant stuck to the surface that other methods/products did not (or cannot) remove.

To take it to a further extreme:

Could one totally eliminate claying by doing a prepsol step instead?

Or are there still contaminants left behind that only claying can remove?

A prepsol-only wipe down will not yield the incredible results you might expect it to.

While some things in this world are not water-soluble, it's also true that some things are not solvent-soluble.

Have you ever sprayed prepsol or WD40 (or some other variant of solvent) onto a gooey blob stuck on the lower body-cladding of a vehicle, only to find that it did nothing to aid in its removal? I have.



After the attempt to remove the unidentifiable goop has failed, the realization sets in that it could be banana-peel remnant, or possibly some animal-part.

Soapy water (or a water-based cleaning product) easily removes it.



In addition to not removing all the above-surface dirt, you'd still have a hard time removing the stuck-on contamination, such as overspray, fallout, etc.

Clay is an incredible invention that was the best thing to hit detailing in decades.

When prepping a surface for refinishing, I've never heard of clay bar being used... Only prepsol + tack cloths.

I would assume claying would be mandatory in the paint refinshing industry if it were the only way to truly prep a panel (not just for removing overspray and for paint reconditioning prep).

When the body shop preps a car for paint, they've already sanded the surface (it knocks the peel out of the surface, and creates a roughened-foundation for the new paint).

They do a wax & grease remover wipe down of the panel to ensure no contamination exists (that could restrict the fresh paint's ability to adhere).

The solvent can also soften the paint a bit, allowing for an even better 'bite' when the new paint hits the surface.



My long-winded response to a short but multi-faceted post.

I shouldn't have had that coffee when I was watching Survivor...

 

[wannafbody]

In order to soften the paint a solvent must be pretty strong. Does the paint then return to it's original hardness or is it compromised? If the solvent softens the paint then it's actually melting the paint and defects should theoretically be lessened. I'd hope that manufacturers aren't using strong solvents in polishes and compounds that could do long term damage.

 

[Kevin Brown]

"In order to soften the paint a solvent must be pretty strong...

Yes, there's some pretty capable solvents out there.

For lack of a better term 'softening' of paint is the only word that can convey what I've experienced.

Thank you for calling me to the mat on my wording-

I just can't come up with an official term used in the body shop realm that identifies the reaction.



Here's one reputable pre clean solvent and their description of what it does:



Product Information - 900 PRE-KLEANO



Application Properties / Characteristics

R-M 900 Pre-Kleano is a silicone, wax, grease, tar and road-oil dissolving solvent.



900 Pre-Kleano will;



- remove contamination from existing paint films,

- slightly penetrate existing paint for good adhesion of subsequent coats,

- clean sanded OEM finishes for repainting.

"I'd hope that manufacturers aren't using strong solvents in polishes and compounds that could do long term damage."

I just checked a few MSDS sheets online, and some of the products used in wax & grease remover, adhesion remover, solvent-based surface cleaner, (and the like) are:

propane, mineral spirits, stoddart solvent, naptha, xylene,toluene, benzene.



Used properly, I doubt there's long term-effect.

Used on a regularly to 'strip' paint surface of LSP's (or as outlined in ABQDetailer's inquiry)?

It could feasibly dry/alter elasticity of the paint surface, accomlishing exactly what we're trying to avoid- Paint degradation.

 

[DSVWGLI]

While a VERY durable LSP can make it tough to remove paint-defects when using a fine polish, most aggressive compounds will rip right through the most durable LSP's currently available.

This is what I have always found to be the case and was quite surprised to hear otherwise. I just can't believe substances are penetrating paint on a molecular level compromising moderate to aggressive polishing/compounding. If we were to use a very light polish with a pad that has no cutting ability (ie:finishing pad) I could see a durable LSP may compromising that process.

 

[Scottwax]

Polishing in the hot sun is not good and it can dry out the compounds and even cause unbalanced breakdown. Always polish in the shade if you can. Not many cars will have issues with silicone.



An IPA wipedown before will always help remove some of the stuff on the top layer.

It depends on the polishes, at least in my experience. I find that using sun friendly polishes in the sun allow them to outgas quicker and reveal the true condition of the paint; however, I would not recommend polishing black paint at straight up noon in the full sun during the summer. Nothing like the sun for finding holograms either. That being said, if possible I will do most of the polishing in the shade if I can mostly for my comfort and pull the vehicle back into the sun as needed to check my work.



Great thread, Todd, very informative!