Repairing a Cracked Airstream Plastic End Cap

I was going to build a bunk over the dinette, but plans change, and luckily I hadn’t yet recycled the plastic interior end cap.  Originally I had decided not to use the end cap, because it had been damaged by the previous owner upon removal.  But plastic can be repaired, and here’s how I did it.

While the giant crack was the major concern, the first thing I knew I would need to do is stop all the little cracks from getting bigger.  The best way to do this is by drilling a small hole at the end of each crack.

Next I needed to make sure the end cap was super clean so whatever I was going to use for repairing the crack would adhere to the plastic, so I went over it with soap and water, then TSP-PF, then denatured alcohol to remove any residue.

I research online quite a bit deciding how I would make this repair.  There are many posts and videos on “plastic welding,” but I think that method is best for softer plastic like ABS.  I tried plastic welding on a small crack, but this aged, brittle plastic just doesn’t take well to being melted by heat.

Next I thought about using a flexible backing and epoxy.  I braced the crack from underneath as well as using some foil tape on the other side to make sure there was no movement during curing.  Then I cut a patch of screen, and  spread some two part epoxy over the crack before applying the screen.  The idea was that the epoxy would stick to the end cap, and the screen would be embedded in the epoxy.  I used foil tape and a brick to hold the screen and epoxy in place while it dried.  I tested this method on the upper part of the crack.  My thought was that I could finish the repair on the bottom (where separation was greater) with a different solution if this didn’t work well.

The epoxy and screen did work pretty well, but the more I thought about it, the more I worried that the cured epoxy would be brittle, and thus would just crack again with road vibration.  The screen would likely keep the two pieces from separating, but the crack would become visible again from the front side.  So I moved on to using something that I would actually need to purchase (what I had been avoiding by trying to use stuff I had on hand).

I also used a piece of steel (an Ikea wall cleat) across the entire front of the end cap to hold the crack closed and strengthen the structure.

I had used Fiber Fix rigid patch while on the road to repair a split in my turbo hose once, so I knew it did a great job of holding together, even under heat.  The product had some pretty bad reviews online, but I think this was because people were not using it correctly.  The product requires UV light to cure, and luckily, that is something I have a serious abundance of, living a mile closer to the sun here in Colorado.  So I re-prepped the large bottom portion of the crack, and applied the patch as instructed.  I then let the end cap sit in the bright Colorado sun for the entire day.  The Fiber Fix cured extremely well, and I don’t think it will ever let go.  It is seriously bonded to the plastic.


I then installed the end cap back into the Airstream, and finished the visible side with a couple of coats of Bondo before sanding smooth and painting.

Laminating the Dinette Kick with Salvaged Aluminum Skin

Today I put the finish on the dinette kick by laminating salvaged aluminum sheet (interior skin) to the front surface.  I’ve found that the 4×8 1/4″ “utility panel” at Lowe’s is the least expensive substrate I can find, and it’s actually a pretty decent product.  It’s readily available (always in stock), plenty strong (especially once you adhere aluminum to it!), and in a pinch can even take a coat of stain and look acceptable on its own.

I cut the new kick panel to size from a salvaged ceiling skin, and then adhered it to the face of the kick plate with DAP contact cement (used for laminating countertops and available at any big box/hardware store).  Because of the inner curve of the dinette corners, it didn’t take much to clamp the aluminum sheet in place (it basically stayed there on it’s own, but I clamped the upper edge to be sure it was nice and tight).  This was fortuitous, as I was not looking forward to building clamp plates to hold the sheet where it needed to be, especially at those inner corner radii.

The salvaged aluminum sheet had some rivet holes from it’s previous life as a ceiling, so I shot rivets through those existing holes to further secure the skin to the utility panel since the holes would need to be filled anyway.

I will eventually paint the skin to match the rest of the Airstream.

I think it came out looking really nice, and it is definitely a strong and sturdy surface that I don’t need to worry about when it gets kicked and banged over and over again for the next hundred years!

My Homemade English Wheel

What started as a joke has become an indispensable piece of equipment.

I had been stalled for months with completing the belly pan, which meant I also could not attach the lower interior skins, since the C Channel on the floor/deck must be exposed in order to buck rivet the belly wraps to the Airstream properly (buck riveting requires access to both sides of the thing being riveted).

The original banana wraps (the curved pieces that go at all four corners of the belly) were extremely beat up.  I had a lot of trouble finding new ones, as I didn’t want to use the black plastic ABS banana wraps that are now being utilized on new-build Airstreams.

I made several attempts at smoothing out the original banana wraps with rollers, sandbags and hammers, etc., but nothing was making them look like they needed to.  I started researching English wheels to shape sheet metal, but they are incredibly expensive.

The aluminum banana wraps are quite soft (which is a huge part of why they are so banged up), so I knew I didn’t need a “proper” English wheel used to shape and form steel.  Thus, I started thinking about what I had lying around that might work in a similar way.

I have these huge, ancient casters that came from my grandfather’s farm.  I always thought they’d end up going on an industrial style coffee table or cart, but I realized they would be great for flattening aluminum.  As a bonus, they are made from really hard rubber, so they don’t cause creases or dents at the edge of the wheels like hard metal might.  I had an extra vice laying around, so I cobbled together this contraption:

It worked!  And while it wasn’t perfect, I was able to get the job done.

For this job, I placed the weights in the following picture over the wheels to get the pressure I needed, but a second vice on the opposite side of the current one will obviously be a more elegant solution.