Best Plastics, Composites, Rubber for structural antenna parts

PEX tubing

I tried PEX tubing ( used for water supply lines ), purchased from a home center. PEX comes in different variations, some are advertised as UV resistant but you would probably have to look that up on the web. I had 1/4 inch aluminum rod, so I got the appropriate sized tubing, but they also sell it in larger sizes. It isn't near as stiff as the gutter ferrules, but it was good enough for my design. I ran into the same problem of only finding the ferrules sold along with the spikes for an outrageous price. The PEX was about $2 for a five foot long section.

It was a tight fit getting the rod inside the PEX, so I cut some pieces of .155 inch weed trimmer line (which is pretty stiff) to the length of the gaps and then put it inside the pex tubing and then used a dead blow hammer to force the aluminum rods in from each end until they were snug against the trimmer line. It made it much easier to be sure the reflector rod gaps were close to right. If you are using metal tubing, the trimmer line won't work too well, but something like pieces of fiberglass driveway markers might work as spacers.

Have fun!

Ultomato plastic tomato cage

I couldnt find the plastics thread anymore, heh. (EDIT by stampeder: I found it and merged them)

Heres 3 - five foot by a little more than 3/8" pieces of UV resistant plastic rod, and 9 - 10 inch UV resistant plastic clips (that can make up to 18 clips for antenna usage). The clips fit a little loose around a standard 3/8" aluminum antenna rod, so some electrical tape would have to be wrapped around the rod for a tight fit. But the price is right, the Ultimato tomato cage sells for $5.98 in the Wal-Mart garden dept.

As far as holding up tomatos goes, I think I can build a stronger, cheaper cage using 1/2 inch electrical pvc and my clip on sch 40 clip on tees, heh.







They list their website on the package as www.theultomato.com, but I keep getting a timeout error when trying to go there.

I wonder how good the UV protection really is.

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On the label it says "Lasts season after season" heh.

Looking at the reviews on the web, it looks like some have been using them for a few years, and have been left outdoors year round in the deep south, where UV rays are much much tougher on plastic. Like here : http://forum.earthbox.com/index.php?topic=1919.0

Heres some additional comments as to where to buy:
"At my ACE Hardware, they're selling them for $9.99. I got mine at Walmart for only $5.98."
"I got mine from Amazon for $5.49 you do have to pay shipping but I cant remember how much that was"
"Got the first one at Home Depot for $5.99 but went back for more and they were $3 each "


Heres some similar fiberglass garden ladders : http://www.gardenersedge.com/

After looking at the Ultomato cages at Home Depots garden center today, I noticed that the label on the Sturdi-Stakes that the cage is made from said "steel reinforced center". Sure enough when I got home, I put a magnet to it and it stuck, heh. So I peeled off an end and sure enough, a 3/8 inch hollow un-seamed steel tube was the core. I should have realized the stake felt too light to be solid plastic. Its still good rod reflector material and answers a lot of questions about its longevity. The bumps on the plastic are there on purpose to have something to grip the string when tieing up tomato or other plants. For reflector use, they wont matter much, but the plastic covering will lower the velocity factor of the reflector. The plastic covering looks to be about 1/64" thick (.5mm), not counting the bumps.
The clips are solid UV resistant plastic though made from the same stuff as the covering, and that was my main point of interest in the thing.

Picture:

rigid PVC 1/4" tubes, to support the gap between reflectors in a GH10 or DBGH

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I bought some rigid plastic tubing at a model building store. They weren't too sure of the material, but it was fairly rigid and good for non structural parts and came in a huge variery of diameters, I think they had from about 1/16" up to 2", with about 40 sizes in between, no exaggeration. The place I went to specialized in tiny materials for building doll houses, train models, etc...

I used 3/8" tube with a 1/4" ID to set the gaps between my reflectors, which were made from 1/4" copper tube. The ID was actually a bit smaller than the1/4" tube, so I used a 1/4" masonary bit to drill out the tube a tiny bit creating a step at the exact depth I needed so I could just shove the reflectors in and they would be at the correct gap. I can take the reflectors out to move the antenna and reset them without having to measure again.

Acrylite FF acrylic sheets (4.5 mm thick) are my choice for attaching NARODs and NAROD reflectors to the center frame structure of the DBGH build (NARODs to NAROD reflectors spacing is 10").

Here are some of its physical properties:
- withstands exposure to blazing sun, extreme cold, sudden temperature changes, salt water spray, etc. It will not deteriorate after many years of service because of the inherent stability of acrylic resins.
- will expand and contract due to changes in temperature and humidity, it will not shrink with age
- a 48” panel will expand and contract approximately .002” for each degree fahrenheit change in temperature. In outdoor use, where summer and winter temperatures differ as much as 100°F, a 48” sheet will expand and contract approximately 3/16”

... and at a fraction of the cost of lexan, making it a very good choice for my application.