Can large hail puncture vehicle sheet metal?

[Dan Robinson]

I was looking at some of the photos of the recent Texas hail damage to roofs in which large holes were punched all the way through - shingles, plywood and all. I'm curious then if there has ever been a case of a car's sheet metal roof, hood or quarterpanels penetrated by a hailstone? The sheet metal in a car roof seems thin enough that in theory, a large enough stone could puncture it and enter the car. I have never once seen an example of this, however. Has it ever happened?

Here's the image of the roof:

https://twitter.com/Sean_Breslin/status/720230362165678081

Either that's really weak roof material (looks a little like particle board), or hailstones with extra velocity due to a horizontal component of motion by the wind.

 

[Marc R. O'Leary]

I would imagine, just based on material properties, that a typical hailstone, no matter of its size, would have a very difficult time penetrating anything beyond even 26ga steel. Its just not dense enough, nor moving at nearly a fast enough speed.

 

[Robert Forry]

Well, I'll say this, at GM we're using a lot of plastic in body panels and carbon fiber components on the exterior of our cars and trucks. This is no secret as all auto makers have done this in an attempt to lower weight and gain an increase in CAFE and MPG of everything we put on the road today. So we could see a lot of hood and body panels destroyed. Where we won't see this is in the area surrounding the passenger compartment. The ga of the steel used makes it far to rigid for even the largest hail stone..IMO

 

[Royce Sheibal]

The hail storm that hit Blair, Nebraska in 2014 was about 4.5 inches in diameter and lasted for quite some time. Houses were completely de-windowed and de-sided. Car bodies suffered occasional punctures through fiberglass and even solid metal sections, mostly hoods. Google it up. The pictures are incredible.

The Aurora, NE hailstorm a few years back had a record stone about the size of a basketball. One similar size piece punctured a home's roof, landing on a man sitting in his front room, killing him.

Some chasers out that day, known as the "hail boys" recorded their efforts to try and not by killed inside their vehicle by the hail. The force of the hail was strong enough to beat the roof of the car down into the passenger section, like a gorilla pounded on it. This is why we call potentially deadly size/velocity hail "gorilla hail".

 

[Matt Tottle]

The roof of most vehicles has a double skin, but even if it is a single skin, the heaviest hailstone on record (about 2lbs) falling at roughly 130mph will knock it in (the "gorilla hail") but doesn't have enough focused energy to actually punch through 18-20ga sheet metal. The heavier the stone the larger it is, therefore the impact energy is spread over a larger area. If it were shaped like an icicle you'd have a big problem, but not with a round/oblong stone.

 

[JF Massicotte]

One big difference between particle board and metal sheet is that the latter will absob energy through deformation where the former will break easier.

Then what Matt Tottle has said is right: you need to concentrate all the energ on a small area to puncture sheet metal.

 

[samuel stone]

increased total velocity vector from the horizontal component of the wind would only increase force if it is still hitting at nearly a right angle to the impacted surface. So windows or side panels are at a greater risk from such a hailstone but the top of a car body would not be. given normal circumstances. (and we all know windows/windshields are capable of busting!!)

 

[alfredo carrion]

I work for one of the big insurance companies as a Catastrophe Claims Adjuster. In the 6 years I have been doing this, and I have probably written thousands and thousands of estimates on hail damaged vehicles, I have never seen sheet metal punctured. You will see vehicles like Saturns made of plastic that will get their panels punctured, but never steel. The hail is just not hard enough to be able to puncture the sheet metal. I have seen hail the size of softballs and grapefruits in person, but never seen a metal panel punctured. Its physically impossible.

Royce, I googled the storm you indicated, I found no pictures of sheet metal or hoods being punctured. I will admit that was huge hail that hit those cars in Blair, the damages in the pics I found were crazy. When all the glass is blown out , you know its big hail. We just had giant hail in Wiley Texas last week, softball size at some points, that totaled every single car we looked at out there.

Hope this helps.

 

[ScottCurry]

Fiberglass, yes (as can be seen in the below photo).










When it comes to metal, this is the only example I could find...

 

[alfredo carrion]

Lol thats the legendary boulder size hail.

 

[James Hammett]

I haven't seen hail break through vehicle sheet metal either. Even in cases where the hail was large and dense enough to tear through wooden roof sheathing and put craters in the ground.

 

[chad albee]

yes. May 3rd 1999, my next door neighbor at the barracks at tinker had a volley ball sized hole in the bed of his ford ranger. Underneath was a puddle. There was a few chunks of ice in the bed and on the ground under it. That storm did some crazy stuff that no one was expecting.