Chemist or physicist?


#1

On today’s show there was a gentleman who was puzzled as to why the black leather seats in his Honda had burned where his son’s Sprite had fallen. Tom and Ray proposed calling their chemistry buddy up the road. However, maybe calling the physics department would be more appropriate ? Instead of a chemical reaction with the seat leather, maybe the Sprite formed little magnifying lenses on the black leather. The gent said it was a hot day, the seats were black, so all you’d need would be a little focus action to increase the temperature and cause the leather to burn.


#2

So leather burns under water?


#3

So, That Explains The Smoldering Cows I Saw Wading In A Farm Pond On A Sunny Day.
CSA


#4

Soda contains phosphoric acid and citric acid if memory serves.


#5

Yup!
I am betting that it was the phosphoric acid, in combination with high heat, that did the damage.


#6

I use to have a business repairing the interior of cars, to include everything from cloth, leather, vinyl, hard plastic, carpet, all the way to headliners. As I was listening to the show, I understood the location of the “burn” was NOT the centermost panel of the seat, but rather the side of the center of the seat. This is critical because when manufacturers produce leather seats, only the centermost panel of the seat is leather, the remainder is vinyl. Most people don’t realize this when paying extra for the leather package.
That being said, this reaction sounds true to a vinyl reaction. Extremely hot vinyl hit by a cool, acidic drink will cause this type of reaction. If you want it repaired, simply take it to any local car dealer that sells used cars and ask the used car manager to give you the name and number of the interior repair person they use. This can be fixed and shouldn’t cost you more than about $50-$75.
I would especially recommend getting this fixed before selling the car as it can be a reason to offer less, but doesn’t cost much to fix.


#7

you never cover leather. leather needs to breath. great show c&c


#8

I have heard this “magnifying lens” theory applied to water sprinkled on plant leaves, causing hot spots underneath. Just another pile of baloney. Some myths never die.


#9

This is actually an example of the Maillard reaction, the browning reaction between amino acid side chains in the leather and the sugar in the soft drink. Wouldn’t happen except with a good amount of heat available. It’s the same reaction that causes meat to brown when broiling or baking. For the same reason, you put some sugar while mixing up bread or biscuit dough so that you get a brownish crust.


#10

Very hot water will will cause leather to “shrink” or deform into shapes and harden. Try it. Bring water to a boil and drop in a piece of leather you do not want.

I have worked with leather for over 40 years and make leather sculptures. This may not be the correct answer but heat, water and leather will react in a manner the caller described.


#11

The caller used the word “burn”.


#12
I have heard this "magnifying lens" theory applied to water sprinkled on plant leaves, causing hot spots underneath. Just another pile of baloney. Some myths never die.
There appear to be some biophysicists out there who disagree. I trust you've done more scientific research on it than they have though...

#13

Well, it is on the internet…

The same site has an article called “Sucking Up To Your Boss May Be Good For Your Health”.


#14

If you notice at the bottom, the original source is a scientific journal, “New Phytologist.”

Looks awfully scientific to me.


#15

I just logged on for the first time specifically to see what ideas people had about this “soda burned leather” question.

It might or might not be pertinent, but the first poster states that the car seat leather upholstery in question was “black”, but the caller never said that; in fact, he reported that the leather turned brown, an indication to him that the spilled soda burned it. Black leather would not show a brown discoloration, in all likelihood.

But apart from that, I found the immature sniping on this forum very discouraging; both posters involved should really check their attitudes, and consider that a public forum such as this is not a good place to bicker like this - if there is such a place at all. Snarkiness and sarcasm in online typed communication is often a sign that the parties involved have limited maturity, poor social skills, or both.

If you’ve been on this forum awhile, maybe it would be a good thing to try to foster clear, respectful, tolerant, and good-humored remarks by keeping to these standards of common courtesy one’s self. When an individual chooses to write in a snarky, childish, or mean-spirited manner, one need not take this personally or add fuel to the issue by responding sarcastically in kind.

If there are monitors reviewing these forums, it seems to me that this little flame war ought to have been flagged and the hostile posts deleted, and/or the posters given warnings. Otherwise, if this is the tone of these forums, newcomers will either be discouraged from pursuing an ongoing participation on the forum or worse, encouraged to similarly post nasty remarks or responses.

When someone acts like a snotty, rude, sarcastic know-it-all on any forum, the mature and socially courteous (peaceful) response should not be equally snide and hostile. Matching snipes blow-for-blow, or escalating the intensity of the ranting and bickering does nothing to improve the situation; rather, if a poster is hostile or a bully, just report him/her to the forum owner or moderator.


#16

I loved the description of Jim’s Davis’s experiment and was anxiously awaiting the results. However, I was disappointed with his experimental method. He stated that he heated the leather to a high temperature then poured the whole can of Sprite on the leather. I suspect that the mass of the entire contents of the can absorbed a significant amount of heat cooling the leather too much to observe what would happen to a few drops of sprite dribbled on the hot leather.

I think that a better experiment would have been to heat the leather, then tilt the leather at the angle of a car seat then dribble a small stream of sprite on the leather and let it run down the leather. I suspect that there may have been a different result since the small amount of sprite should have been vaporized instantly.

However a previous post suggested that the seat was actually vinyl, and in that case the experiment was using the wrong materials.