All about rivets

Your Airstream is made of aluminum, but rivets are what make it strong. Take those 5,000 rivets away and you’ve got a floppy pile of soft metal.

In this age of robotic vehicle assembly you might be surprised to learn that each one of those rivets was placed on your Airstream by hand by a pair of skilled workers at the factory in Jackson Center, Ohio. Those two people had to practice relentlessly and demonstrate their skill on practice sheets before they had the ability to repeatedly install rivets with speed and precision.

It’s not an easy thing to get right. At Alumapalooza we have held Rivet Masters contests for several years, where attendees get a quick lesson on how to put in a rivet properly and then compete for the fastest times. Most of the contestants are lucky to get about half the rivets in correctly even with some practice.

“Bucked” solid rivets

Most of the rivets you see on the exterior of your Airstream are “bucked” (solid) rivets. They start life as little mushroom-shaped bits of aluminum. These very strong rivets hold two panels together, or fasten a panel to one of the trailer’s internal ribs. This bond will last the life of the Airstream, unless damaged in a collision.

To install these requires a team of two people working together like dance partners.

How to buck a rivet—The outside installer holds an air-powered rivet tool, which is sort of a miniature jackhammer that pounds on the mushroom head of the rivet.

The inside installer holds a shaped metal tool called a “bucking bar” that is pressed against the tail (or stem) of the rivet. The rivet gun very quickly hammers the rivet, pushing it inward and squashing the tail against the bucking bar, which causes the tail to get shorter and wider. This fills the hole and locks the two pieces of aluminum together very strongly.

Under normal circumstances, this rivet is in place forever, and it seals so tightly to the body panel that sealant is not needed for the rivet to be waterproof.

 

Timing is critical. Stopping too early means the rivet won’t fully deform and thus it won’t fill the hole for maximum holding power. Hammering too long will flatten the rivet too much, which also lowers its strength and can look cosmetically awful on the exterior.

The difference between “too short” and “too long” is less than a second, so the riveters rely on their experience and the tone of the hammering to know exactly when to stop. Then, as a pair, they move to the next rivet without delay. Good teams can put in a perfect rivet every three or four seconds.

Blind rivets

Also known as “POP” rivets, these are mostly found on the inside of the Airstream. (POP rivets was the original brand name.) These rivets are easy to install and replace, using a different kind of rivet tool. Since you can put one in without needing access to both sides of the aluminum, it only takes one person.

Hand held rivet toolA hand-operated rivet tool is something that should go into your everyday tool kit, because blind rivets do occasionally break and replacing them is a very easy job if you have a few spares and the rivet tool on hand. If you buy a tool, don’t skimp on quality. A good rivet tool is a pleasure to use, whereas cheap ones can be awkward and prone to jamming.

A single broken or missing blind rivet is not a serious issue. You’ll know a blind rivet is broken because it will either be obviously loose, missing, or you’ll see a little ring of black around the head of the rivet. (The black ring is aluminum oxide, caused by the loose rivet head rubbing.)

To replace a blind rivet, you put the thin end of a new rivet in the tool (the thin end is called the mandrel) and press the wider tail end of the rivet into the hole. Hold the rivet tool firmly against the surface while squeezing the handle three or four times. This makes the rivet expand in the hole and eventually the mandrel snaps off, which tells you the job is done.

The video below is a quick demonstration of how easy it is to install a blind rivet.

Blind rivets and drill bitsAirstream uses a variety of pop rivets, but most are aluminum and most have 1/8” diameter body or 3/16” diameter body. You can find the basic type in hardware stores. There are also specialty rivets with extra-wide heads, used for belly pan repairs. It’s a good idea to have a few of those in your tool kit too. Check the Airstream Life Store for those, and for a good rivet tool.

 

 

Shave-head or “Olympic” rivets

These provide the same function as bucked rivets but have a major advantage: they can be fastened from the outside by one worker. This is really useful when an exterior body panel has to be replaced. To do that repair with bucked rivets would require removing the interior furniture and interior panel so that one worker can get access from the inside. This adds considerable expense to a repair, and so quite often owners (or their insurance companies) opt for a shave-head (often called “Olympic”) rivet instead.

The design of this rivet is clever. It is installed just like a blind rivet but when you squeeze the handle of the rivet tool, three legs of the rivet billow outward like petals of a flower, on the opposite side of the panel where you can’t see it. These three legs enable a strong bond—not as strong as a bucked rivet, but adequate for repairs and patches.

After a shave-head rivet is installed, it has an obvious bump in the center of the rivet head that doesn’t look as nice as a solid rivet. It’s a remnant of the rivet mandrel that broke off during installation, kind of like a belly button is a legacy of an umbilical cord. To make the rivet look just like a bucked rivet, there’s a tool called a “rivet shaver” which cuts off the bumpy part of the rivet stem and polishes the head so that it’s much harder to tell it was installed as a replacement. Now you know why these are called “shave-head rivets.”

Interestingly, current technology could allow Airstream to build aluminum trailers using only adhesives instead of rivets—but you probably wouldn’t want that. Rivets are more than just a way of fastening the metal together. They’re part of the “look” of an Airstream, thousands of little reminders of the strength and durability of your travel trailer, and a connection that reaches all the way back to the origins of Airstream in the 1930s.

For more on rivets and riveting, check out our video: