Came across a completely new idea (through my favourite Dutch blog ofcourse 😀) and remembered I had a ball of Scheepjes Whirl yarn (553 Indigo Plane) laying around that would be great for this project. I would have rather used Unicat yarn but I can't find that in stores here at all. 
You basically crochet a doily or table cloth and stretch it inside a hoop. (we used to make them in the 1970ties, but with thin white cotton, so they ended up much smaller, to hang in the window).
My biggest problem was to find a VERY LARGE ring to fit this. Needed to be at least 100cm (40") in diameter. I only found 1 place online and it was close to $100. Little too pricey for my taste.
Many people gave me suggestions and eventually I went with connecting 2 hula hoops and spray paint. I used up practically all the yarn and it made the mandala 110cm (43").
I'm not completely satisfied with the spray paint. Suppose to be for plastic but here and there it didn't stick very well so there are specks of bright pink hula hoop showing through. I'll have to touch that up. But you can't see it from a distance so overall I'm very pleased with the result.
As a lucky coincidence the blue mandala matches my Persian tile blanket hanging on the railing. I had not planned it like that, only noticed it when it was on the wall.

Update June 2022
I ended up selling this mandala to a friend but more of the paint came off while moving it around. Someone suggested using hockey tape to wrap it and that worked GREAT. Apparently it comes in many different colours (didn't know that because we had girls and never were involved in hockey) so this is a very good option for future projects. I will have to make a new one like this again because I love the look of it in that spot. Just don't have any time right now.

This is the "Meu Mundo" Mandala.
You can find the pattern in graph form for free on the internet

Update August 2021
I have since made 2 more in different designs, both in Scheepjes Whirl yarn.
Both these hula hoops are wrapped in a burlap sticky tape, which also looks very nice

The Peacock Mandala in Scheepjes Whirl 776 Rosewater Cocktail

The Celestial Mandala in Scheepjes Whirl 788 Night Time Bubbles