I’ve spoken of the grapes we grow before. One of my two readers asked about the arbors that support them. The other one was uninterested.
So I’m going to talk about the various arbors I’ve built. Let’s be very clear. I’m belong to the Brut Forse Carpentry Skool of Construkshun. It doesn’t have to look nice. It just has to work.
We all have a pretty good idea of what arbors tend to look like. The picture up there is a fairly common style. Essentially, it’s a set of four or more posts with a set of cross beams. I’ve built a couple of these using 4x4 pressure treated wood and set into concrete. They last about ten years or so without some sort of maintenance—paint and the like. However, I don’t like to paint around things I eat. So I tend to replace them.
There are a few of things to note about this arbor. For one thing, there’s a lot of wood—more than when I built it. A tree fell on the arbor and I patched it together. The other is the half A-frame construction. Note that one side falls at a slant. It’s not a square shape.
I started doing this because I wanted a fairly broad surface area for the plant. But that meant that to harvest I had to reach over a long distance. The answer was to mount the arbor at the slant and harvest from the back of the arbor instead of the front. I’ve retained this for a couple of arbors.
Then a tree fell on one of them. (The one pictured.) And the others started to rot. Pressure treated is sort of a suggestion against rot rather than a preventative.
Meanwhile, I was working in Cambridge and when I walked around I saw some old grape trellises made of plumbing pipe. This turns to have been a thing for many first generation European immigrants. They ended up in these small houses with almost no space so they would build a trellis of pipe over the driveway or other similar space and grow grapes over it.
Most of these constructions used galvanized pipe and plumbing fittings. With any luck, these arbors might outlive me and I was tired replacing wooden structures. So, why not?
I was attempting to minimize cost. So I used relatively thin black pipe and plumbing fittings. Note that though the top rail is straight, the bottom rail is staggered. This is because I wanted the cross beam at the bottom and needed the staggering to fit it in with the cross posts. The black pipe turned out to be a problem in that it is more rust prone. I’ve been using Rustoleum’s rust converter to correct this. Wire is used as the material for the grapes to grow across.
This particular arbor is not currently in use. Originally, I just stuck them in the ground. But I’ve concluded this is a mistake. First, the arbor can rust—although there’s not much evidence of it here. Second, the arbor can sink asymmetrically. The thin pipe works in this arbor but that’s because of the inherent bracing of the shape.
I measured the rise and fall of the ground over that winter and concluded the whole anchoring problem was an illusion. Grapes live on trees and trees creep much more than a stationary arbor. Instead, I put the base in hollow concrete bricks which I then fill with concrete. I’ll straighten this one and fit it into concrete overshoes next year.
Working with the plumbing joints in a complex structure turned out to be really, really tedious. Imagine trying to screw everything tight. I was going to weld them but then read about zinc poisoning when welding galvanized pipe. I looked around for an alternative and found KeeKlamps. These are galvanized fitted sleeves that can be tightened over a pipe with a hex wrench. They come in a variety of fittings and are very easy to use.
But this time, I came up with a different way to mix the kee klamps with plumbing fittings. The KKs are the joints that preserve the angle: 3 triples on the top and three single fittings on the base pipes. But instead of a complex corner joint I just used 90 plumbing fittings. This is worked out really well.
All of these structures are pretty utilitarian. I can understand if someone found them ugly. But they do work.
That said, I’ve been looking at some images from a simple google image search of “DIY Metal Arbor” or “DIY metal trellis”. Some of these have been stunning. Some used simple copper pipe sweated together. Some have bent normal conduit pipe (much softer than plumbing pipe which is why I haven’t used it.) into magnificent shapes.
Gives me some ideas. Heck. Maybe next year I’ll break character and make something beautiful.