Get a cheap plastic form- a large plastic plant pot would work well. Line with tinfoil or plastic wrap. Cut a large hole in the bottom of the pot and the tinfoil. Turn it upside down in the spot you want the bollard. Fill with quick-set concrete. When the concrete is set, take the pot with you so you can make more, the foil should keep it from sticking. If you can work out a way to get some metal wire into the concrete form before you pour, it’ll be much stronger.
Downsides to this could be getting enough concrete and water to the site- shit is heavy. Also, while it should be set in an hour or two, getting knocked by a car right away might kill it.
Get a cheap plastic form- a large plastic plant pot would work well. Line with tinfoil or plastic wrap. Cut a large hole in the bottom of the pot and the tinfoil. Turn it upside down in the spot you want the bollard. Fill with quick-set concrete. When the concrete is set, take the pot with you so you can make more, the foil should keep it from sticking. If you can work out a way to get some metal wire into the concrete form before you pour, it’ll be much stronger.
Downsides to this could be getting enough concrete and water to the site- shit is heavy. Also, while it should be set in an hour or two, getting knocked by a car right away might kill it.
I looked it up and an 80 pound bag of concrete needs about 3L of water. That all seems doable.
Anyone know how long it would take to set?
Make sure you get fast-setting concrete. It’s the difference between the time being about an hour vs about a day.
I would expect it to be set enough that you could remove the form after a half hour to an hour