I had the last two weekends to get started on this project. It will be unlike anything else I’ve ever done, so some new skills to learn and use. I’ll be making my first attempts at using a vacuum bag, I’ll be building torsion boxes to provide a lightweight but stiff, substantial structure, and I’ll be using bent laminations more than usual. It should be fun.
Usually I build from solid woods and use traditional techniques. I’ll use some of that but there will be a lot of plywood too. I first thought about how to build this using solid wood and quickly realized the number of challenges and sheer weight I would be dealing with. Plywood torsion boxes are the way to go. And since I’ve got some curves, I decided using a vacuum bag would help. It is sort of contemporary after all.
I did my drawings by hand at 3” = 1’-0” scale. For figuring out the joinery I simply took a piece of MDF and sketched and worked out the sections through the joinery. I felt well prepared and like I had solved all of the problems before I cut any wood.
So the first step ended up being building a vacuum bag setup. I spent some time researching this, but in the end I didn’t want to spend a lot of money on a setup I may not use frequently. I could see the usefulness though. I ended up with a homebrew setup from www.joewoodworker.com using a Venturi Pump.
It’s a clever system that uses a compressor (I have a small Porter Cable pancake compressor) to create the vacuum. I built it over two evenings and it worked the very first time, without any messing around. I’ve already veneered several panels and the system works well. I don’t do endorsements but this thing works and seems well thought out.
I started by building the side ribs and frame around which the side panels will wrap. I built the top and bottom frames and worked out the joinery. I’m probably the only person that uses dovetail joinery for this sort of design but it’s a pretty strong joint and I like it better than just nailing or screwing. The joints between the top/bottom and sides will be an over-sized splined joint. In testing I’m confident this will be a very strong joint and will be completely hidden.
Next I laid up the curved outer panels on the sides. I used ¼” cabinet grade plywood and urea formaldehyde glue. I wanted the rigid glue line and no creep. I debated using the vacuum bag but decided it would be simpler to just use clamps and cauls. Here you can see my assistant (My dad works for Turkey on the day after Thanksgiving) helping with the clamping. Easy Peasy.
So here’s where I am after about 9 days of occasional work. Next up the back panel and interior panels.