Into the belly of the beast…

We’ve spent over 10 years thinking about replacing the floor….a significant undertaking. There are many great videos and tutorials online about how to go about it, so we knew what was in store. The main concern was what state we would find the chassis in.

Airstream completely wraps the frame underneath the trailer with an aluminium belly wrap. That meant there were very few places we could see the state of the chassis. Some of the online photos and videos we’d seen of other airstreams was a horror story of steel corrosion, broken outriggers and more, needing repair, welding or even an entire new chassis.

So the day we removed the banana wraps (the curved bottom end caps) and the front belly pan to being the floor replacement was a big day.

We were thrilled to find only surface rust, no holes or broken outriggers. On average, 6 desiccated rodent carcasses per section of floor we’ve removed, but so far it’s all going swimmingly.

We are only replacing one section at a time – because the whole upper cabin is bolted to the frame through the floor. By working in sections it feels more manageable, but also the frame can’t move or spring away.

Some of the floor ply is in reasonable condition, but it’s hard to really assess what is going on under the edges of the frame. And even plywood that is not rotten tends to feel spongy after this many years. We’ve decided to replace the whole floor with high quality, marine grade Gaboon plywood. It’s lightweight and lovely to work with. This particular brand uses Gaboon in the core as well as facing layers, keeping the weight down and quality up.

Megan was in the US when we started the project, so we ordered special Elevator bolts that Airstream uses to attach the floor for her to bring back. We are going to need a lot of them…

Lower walls removed for access to the bolts and screws holding the frame to the floor.
Rot under a window that used to leak – showing the old elevator bolts. The new ones have bigger heads.
Not really a lot left under the front windows after years of leaking. This model Airstream has a steel plate at the front of the chassis that is riveted to the body – so no front end separation, but also not a very solid foundation.
Queue massive sigh of relief…..only surface rust.
Frame cleaned up with a wire brush on a drill, then treated with rust converter. Looks like new!
Primed frame, good as the day it was built in the factory.
Epoxy top coat, ready to go.
New floor ply in place. This front section is where the spare wheel carrier would be installed (ours did not have one). We aren’t going to replace the centre section of belly pan – we’ll feel better being able to keep an eye on the chassis and rust.
And a lovely new floor. The outer walls extend below the bottom of the frame – so its not possible to slide the floor in one piece. The join is just to the outboard side of the frame with room for both pieces of ply to be bolted to the outriggers keeping them firm. The join is spliced underneath with a 100mm wide piece of floor ply, glued and screwed in place.