Do you think hardware buried under ground will last very long?
It depends. How wet is the soil? Is the soil acidic or alkaline? How strongly acidic or alkaline. Is the wire galvanized?
When iron or steel contacts oxygen a chemical reaction occurs. It forms iron oxide, commonly called rust. How fast that happens depends on the laws of chemical reactions. Do you know the pH of your soil? The more acidic (below 7.0) the reaction is pretty fast. If it is alkaline (above 7.0) the reaction slows down. Water can provide the oxygen as water is H2O.
One way to slow that process is galvanic action. If you coat the steel with certain minerals (like zinc) the oxygen combines with the zinc and ignores the iron. If you scratch the zinc so the iron is exposed you can get concentrated corrosion at that point but that is why so many fencing materials and other steel or iron items are galvanized. What might be gone in a year without galvanizing could last for years if it is galvanized.
One way to extend the life of galvanized steel is to paint it. Painting regular steel works too without galvanizing but properly painted galvanized steel can last a very long time.
How do I know this? I used to work in the oil patch, mostly offshore. The splash zone (down at the water line of the platforms) was constantly wet with salt water, even more corrosive than fresh water. We had walkways and handrails down there. They were galvanized before they were installed. When we had to repair them we used welding. If we did not sand blast them clean and then paint them they rusted away in no time. We noticed that when the repair paint was oversprayed on galvanized grating that grating lasted a lot longer. We talked to some experts and they said the paint is keeping oxygen away from the galvanizing, greatly extending its life. It was extremely expensive to replace that grating and handrails down there so we soon started painting that area still in the fabrication yard before it was installed. And we were careful to repair scratches down there.
@Ch1cken7 I don't know the pH of your soil so I do not know how fast buried galvanize hardware cloth will last. If you can keep from scratching it, probably quite a while. Painting it can be expensive, messy, and take some time but that would extend its life much more. I never considered painting it worth it to me.
Will that plastic coating slow down corrosion? If it keeps air or water away, absolutely.
Could a raccoon rip through that??
I'll include a link that has photos of what a big dog did to hardware cloth. A big boar raccoon could do this type of damage also.
Dog Vs. Hardware cloth... | BackYard Chickens - Learn How to Raise Chickens
Hardware cloth, even the thin stuff, will stop the vast amount of predators. But there are always exceptions to about anything. I consider even the thin 1/4" hardware cloth to be really effective.
A big concern is how you attach it. Often the hardware cloth holds up but the attachments fail and allow the predator in. It is a system, made up of components, and only as strong as the weakest component.
I don't know if any of this helps you with your decision or not. Good luck!