Why does paint bead so much after polishing

[HUMP DIESEL]

Alright, someone let me know is it because of the polishing oils or the slick finish?

HUMP

 

[Setec Astronomy]

Combination?

 

[cleanmycorolla]

healthy paint beads naturally

 

[DetailKitty]

Anyone correct me if I'm wrong:

My understanding is the wax or newly polished surface has less or no imperfections in the paint, and reduces friction for anything on the surface, meaning that water has less to grab onto. So surface tension makes it rather spherical (think raindrops) and it slides down easier. Also, the molecules of the wax are larger than those of the water, meaning that the water cannot pass through the barrier created and keeps it's "drop" shape.

 

[FUNX650]

Among other factors:
•Cohesive forces among liquid molecules
•Interaction between dissimilar liquids.
•Thermodynamics

Note:
The aforementioned cohesive forces are the cause of surface tension.
Surface tension is responsible for the shape of liquid droplets.

Bob

 

[hernandez.art13]

I would like to say polishing oils.

A car that has freshly polished paint will probably bead water probably due to the oils left behind.

That is why when you do IPA wipedowns, the goal is to remove anything off the paint including polishing oils. So what ever your trying to apply to the paint as in LSP. (We'll say a coating in this case.) Can bond properly with nothing left behind in the paint.

Run water from the hose after doing polishing only and then run water after doing IPA wipedowns and you will see almost zero sheeting if done correctly.

 

[GenesisCoupe]

I am going to say polishing oils make it bead, but i doubt that lasts since its not really any protection factor...

At times I will use Poorboy's Polish with Sealant, that is a nice light polish for a perfect one step. That beads for a little while. Win win...

 

[Paul A.]

Isn't clean paint naturally hydrophobic? I always thought so but readily admit i don't fully understand the science of it. Paint chemicals? Polymers or things naturally used in paint? Plus, as some have said, any left over oils or chemicals left from the polish?

 

[hernandez.art13]

I like to think of paint as spongy. Where it can absorb a number of different things.

So that is why we add LSP. As a layer of protection. Waxes, sealants, coatings etc...

So let me try and explain my hypothesis.

Imagine a sandwich just sitting there on the table. (Just regular white bread) Well if anything lands on the bread, it will get absorbed. We'll say kool aid in this instance. So it now got absorbed.

Well if we wrap it in a seran wrap, now you have a layer of protection between the bread and its surrounding by the piece of seran wrap.

So applying sealants, waxes coatings is like the seran wrap in this case.

That's just a hypothesis that has popped into my head over time, from always thinking about detailing.

Side Note Question: those of you that live out there where it snows, you guys every morning wake up and don't let the snow melt on the car? Why?

 

[DetailKitty]

Side Note Question: those of you that live out there where it snows, you guys every morning wake up and don't let the snow melt on the car? Why?

I'm assuming you are being serious Bro?

It's because if you did... you'd be out of work for a week waiting for it to melt :laughing:

 

[hernandez.art13]

I'm assuming you are being serious Bro?

It's because if you did... you'd be out of work for a week waiting for it to melt :laughing:

Hahaha it was actually a serious question since I am a SoCal guy.

We'll my aunt who is a US Marine had bought a car and and took it to NC . Well she said every morning while it was snowing her neighbors would wake up and go take off the snow off their cars.

She said it in a way to as why and it was weird...

We'll she didn't and now the car has CC failure all around. So that is where I came up with the paint is like a sponge theory.

Since the CC failure wasn't like anything I had seen before. It didn't necessarily look like it was dried and old.

It looked like the CC bubbled up. Like a blister...

When I head out to PA. I am taking extra socks. Lol I have a feeling that I might not like the weather out there.

I bought a new camera off Amazon! Should be here tomorrow!

 

[cleanmycorolla]

Side Note Question: those of you that live out there where it snows, you guys every morning wake up and don't let the snow melt on the car? Why?

Air temperature, ground temp, ice won't melt if it's freezing out, and even if it's a tick above, it can take hours for it to melt, days depending on how much. Pretty basic stuff.

 

[hernandez.art13]

^ I am starting to think also, but can't prove it since it never snows here. That if one lets the snow melt on the car and the car has no LSP on the paint. Overtime it will absorb the water from the snow.

Guess not pretty basic stuff.

 

[DetailKitty]

When I head out to PA. I am taking extra socks. Lol I have a feeling that I might not like the weather out there.

Depends when you are out... if it's September it will most likely still be hot as hell and just as humid... no socks needed.

 

[hernandez.art13]

Ok Sounds good. I just won't pack socks Lol

 

[57BORNTORUN]

We have a saying in the food science world...Fat head water tail molecularity.Think of fat based salad dressings.If they don`t have a cohesive substance the dressing separates.In other words fat and water don`t mix.Water is heavier so if fat is applied first the water has no where else to go but off. A little off topic but a least you learned to shake your salad dressings before using.

 

[FUNX650]

•When I head out to PA. I am taking extra socks. Lol I have a feeling that I might not like the weather out there.

•I bought a new camera off Amazon! Should be here tomorrow!

•So that is why we add LSP. As a layer of protection. Waxes, sealants, coatings etc...

•So let me try and explain my hypothesis.
-Imagine a sandwich just sitting there on the table. (Just regular white bread) Well if anything lands on the bread, it will get absorbed. We'll say kool aid in this instance. So it now got absorbed.

-Well if we wrap it in a seran wrap, now you have a layer of protection between the bread and its surrounding by the piece of seran wrap.

-So applying sealants, waxes coatings is like the seran wrap in this case.

-That's just a hypothesis that has popped into my head over time, from always thinking about detailing.

•Side Note Question:
-those of you that live out there where it snows, you guys every morning wake up and don't let the snow melt on the car?
-Why?

:wow: ...You're all over the place today Art!!

I like to think of paint as spongy. Where it can absorb a number of different things.

We'll my aunt who is a US Marine had bought a car and and took it to NC . Well she said every morning while it was snowing her neighbors would wake up and go take off the snow off their cars.

She said it in a way to as why and it was weird...

We'll she didn't and now the car has CC failure all around. So that is where I came up with the paint is like a sponge theory.

Since the CC failure wasn't like anything I had seen before. It didn't necessarily look like it was dried and old.

It looked like the CC bubbled up. Like a blister...

Bob

 

[Tato]

Good thread.

From my practical observations (wash after polishing and before LSP mostly every time), it's a combination of both (and even many other factors we are not considering).

I observe:

a) Lots of beading while starting rinsing the just polished surface.

b) Diminish of beading after washing with a strong prep. soap (generally Hyper Wash from Meg's, it's what I have and use often)

c) Maintenance of effective water sheeting behavior in the end of the wash.

My explanations:

a) Surface is properly leveled, and although I buff off polish residue 'to exhaustion', it's likely some oils will remain. The water 'reacts' right away showing the existence of those oils.

b) Using a strong soap like Hyper Wash is very likely to remove those polishing oils. The beading is now not so evident, if any remaining.

c) Sheeting is preserved because the 'other factor' - perfectly leveled surface - is in place, which makes water 'slide' over it.


Please, any of my comments are 'scientifically proven' or scientifically explained by me above. Just general thoughts and my observations.

Kind Regards.

 

[hernandez.art13]

:wow: ...You're all over the place today Art!!



Bob

I'm actually just about to start a new thread, where I figure other members can share their thoughts. It's everyone's favorite subject too. Holograms rops:

 

[mwoolfso]

Anyone correct me if I'm wrong:

My understanding is the wax or newly polished surface has less or no imperfections in the paint, and reduces friction for anything on the surface, meaning that water has less to grab onto. So surface tension makes it rather spherical (think raindrops) and it slides down easier. Also, the molecules of the wax are larger than those of the water, meaning that the water cannot pass through the barrier created and keeps it's "drop" shape.

Isn't clean paint naturally hydrophobic? I always thought so but readily admit i don't fully understand the science of it. Paint chemicals? Polymers or things naturally used in paint? Plus, as some have said, any left over oils or chemicals left from the polish?

Anything that repels water molecules is considered hydrophobic. So whether the paint is clean or dirty, both paint states are hydrophobic relative to the painted surface.

Water droplets have no fixed shape of it's own. A clean surface will permit the water droplets to behave with less "external" influence relative to the surface itself, leaving gravity and surface tension to produce the end state of the droplet.

So then if the paint repels water no matter the condition, why doesn't water bead when resting on a dirty surface? Where did the water go? Well, the dirty surface is not hydrophobic. Think of the dirt as a layer sitting on top of the painted surface. The dirt molecules are larger and stronger than water molecules. The water molecules have little chance to coalesce and form a sphere because they are being pulled apart from each other due to a natural attraction of water to dirt. Basically, the dirt absorbs as much water as it can unless it is saturated. At the point of saturation water does begin to coalesch and "pools", creating yet another layer on top of the painted surface (sheeting).

What keeps a droplet spherical? The surface tension between the water and air is consistent across the entire surface of the droplet, and since they are equal all over at the molecular level, a sphere becomes it's natural shape. However, even a water droplet in the air will not be entirely spherical because gravity is pulling the droplet "down"; hence a droplet is really pear-shaped when not resting on a surface.

Is a water droplet spherical when resting on some surface? No. The bottom portion of the droplet will take the shape of the surface unless the surface tension of the droplet is more than the surface can handle. A frozen droplet will behave very differently than a liquid droplet on the same surface. As the weight of the droplet increases, gravity will have more influence on it. This is why, over time, you see beads running off a surface. It is a natural battle the water droplets have with the air, every pico-second, while gravity is pulling it downward. The top part of a bead resting on a surface becomes naturally oval.