Subfloor

Today I did some dancing! It was every bit as (un)graceful as you're imagining. But I couldn't help myself. I finally have a floor! A whole floor!! Do you know how long I've waited for this day?!?! 

Granted the floor is not secured, which is why you can see the uneven edges of the plywood. But once I bolt the four new panels down, there will be almost no visible seam. So here's how I did it, just like last time:

First, I got out the cardboard template that I used on the back half. I assumed that Airstream, in an effort to make things easier for everyone, used the same curve in the front and back. Fortunately, it was very close. I trimmed off a small amount and had a working template in about 10 minutes.

Fitting the old template.

Trimming a little at a time.

It fits under the C-channel. Like a glove.

From there, I transferred the curve to a piece of plywood with the rest of my measurements and cut.

Let me pause and tell you about the plywood itself. Lots of folks have lots of ideas about what to use for restoring Airstream floors. Some people swear by marine-grade plywood ($$) because it has no internal voids. This means less to rot, less trouble securing it to the trailer, and better piece of mind. Some even go so far as to use composite ($$$) material, which will never rot. I found a really quality board at my orange box store. I think it was cheaper when I did the other side, but these panels were $35 per sheet. For reference, marine-grade plywood can be about $75-$100 per sheet. The sheets I used have been perfect. Not cheap, but not nearly so expensive.

Transferring the curve.

Sliding it in.

Next, I coated the edges with triple-thick polyurethane to give it some protection against rot. It's probably better to use spar-urethane or something tougher. But this poly was easy to use and seemed to coat very well. I wasn't going for pretty, either. I used a rag and glopped it on. That's a technical term. I figured thicker is better.

Smearing on the polyurethane.

Thick enough to have waves.

Thick coating on the edges.

As each panel dried enough to handle, I carefully placed it in. And by "carefully placed" I mean I beat it with a mallet until my wood block shattered. The walls flex, so I could get the wood roughly in place. But getting each piece into final position took a ton of careful bashing.

But, it ended well: