Thanks, drthor. I considered binder clips but I didn't find any I thought would work for 1/2" PVC. The biggest ones (1" capacity) looked like they might work for someone without arthritis but I couldn't get them open wide enough. I'll try again.
If the Johnny's ones fail I certainly won't spend money on those! I don't think we normally have they wind you have, but often big storms pop up without warning.
Stephanie, what larger binder clips are you talking about? The biggest I can find only have a 1" capacity -- technically big enough if I could get them open.
And do you know what the hardware clamps you are talking about are called? We don't have an old fashioned hardware store here (alas), and I haven't found anything at big orange, big blue or Harbor Freight that looked promising. I don't mind ordering online tho!
Someone suggested cutting 2-4" lengths from very big, black stiff-but-flexible tubing from Home Depot, then slitting them. You might have to use a LOT of them for high wind.
I don't know just what kind, but the plumbing section was polyethylene in many sizes (like 3/4" - 1" - bigger.
However, the smallest of those rolls looked like 50' to me! Maybe there were 5 foot or 10' lengths in some other section of the store.
I always thoguht that, if I had HIGH wind, I would run an extra row of hoops OUTside the plastic . And maybe run horizontal stiffeners along the inner layer to reduc e flapping (called "purlins" by some).
[quote="drthor"]I use office clips.
I bought the Johnny's ones and they flew away during high wind.
The office clips are very strong and they didn't move even when it did snow and the fabric started to get heavy.[/quote]
Don't the "office" clips tend to rust out pretty quickly? They're not engineered for prolonged outdoor use.
I've used the office clips and was happy with them, but my old ones are really starting to rust. And when they do rust they break when one tries to remove them and pieces go flying. So I'm going to make up some of the tubing clips as described above. I'm in a really windy area, so I've also found that the cheap smaller stone (or some other heavy material) pavers are very helpful. I just plop them on the bottom edges and they really work. Easy to pick up and they can be resued for all sorts of things.
For ready made I like the ones I found at Greenhouse Megastore called Snap clamps. https://www.greenhousemegastore.com/product/snap-clamps/hobby-diy You can buy a 4' length already sliced for $2.60. That would not be difficult to cut to the length one desires. They also offer 4" lengths for $.51 each but cutting one's own saves a lot of money.I would guess that the longer lengths might hold up better against strong winds.
They also offer aluminum grip clamps https://www.greenhousemegastore.com/product/grip-clamps/hobby-diy to use over the snap clamp if more strength is desired but that adds extra expense yet should work. I have used this company for many things and been very satisfied.
Interesting link, gardadore. I'd thought of using PVC, but the next size up was too big to hold securely. I see they are using the *same* size but in what they are calling thin wall PVC. I haven't seen any thinner PVC than schedule 40... but then, I haven't been looking...
We might spend a lot of money buying 50' rolls of 1" tubing before finding the right kind that was flexible enough to fit over a PVC pipe, but stiff enough to hold things down.
It amazes me that PVC pipe has enough flex to open at all, but cutting a 1/2" slot must help. Good idea about smoothing the edges! I wouldn't have thought of that, and then had to replac e the film.
BTW, can youj use "cloudy" or trnaslucent plastic film? I bought some 3 mil film for a tiny heat-holding tunnel, and wondered if it let enough light (or heat!) through, to keep plants happy. Does the film have to be clear for plants that wnat "full sun"?
P.S. I saw a scheme for clamping two boards onto a long section of plastic film, to hold it down tight against the ground. I can't find my notes, but it was something like two 1"x2" boards nailed or screwed together, with the PVC wrapped around just one of the boards. The boards' edges clamped down on the film so that it didn't matter if the screws pierced the plastic. Any stress from the film flapping was distributed evenly along the edges of the baords so there was no tendency to tear. A few bricks or stones on the boards was enough to weigh down a 10 foot run.