ferro cement help needed (mix & technique)

I want to try my hand at building a ferro cement water tank for rain water catchment. Maybe bigger projects later but I thought this would be a good start. I grabbed some 1/2" hardware cloth and made a sample cylinder because I figured my first attempt would be terrible so I'd learn somewhere else before a "real" project.

So a couple of videos I've seen:

So in this one there are two layers of hardware cloth and I think they trowel into both sides.

[url=https://www.youtube.com/watch?v=lJwFb_qKI-Y]When I first saw this one I thought it was only one later, but turns out it was chicken wire on both the interior and exterior of the rebar, I imagine there's some hollow in the middle

I guess in general I'm just looking for some guidance. We just put ours on by hand rather than a trowel. Initially we tried readi-mix but then when with 1:2 portland : #20 sand . Often when we put it on it just didn't adhere to the mesh and went through like a waffle press or just fell back directly.

I have a book by S.B. Watt but he opts for using interior temporary forms, which I'm trying to avoid. If I had to I suppose I could get some plastic roofing panels and make it work but that's just more money for things I don't really need.

This video shows clearly 2 extra things;
- temporary formwork
- pressed metal mesh which grips the ferro cement


And another which shows how to build a tank, using a few layers of mesh and no formwork


What is ferrocement?
Ferrocement is a type of reinforced concrete and also known as a composite material made up of closely spaced one or more layers of mesh, and cement mortar which is covering the entire mesh.
The inventors of Ferrocement are Frenchmen Joseph Monier and Joseph-Louis Lambot who constructed a boat with the system in 1848 and later developed by an Italian architect P.L.Nervi in 1940.
Further, it is defined by ACI (American Concrete Institute) committee 549, in 1980;
Cement mortar is reinforced with single or multiple layers of continuous small diameter wire mesh;
Mortar provides the mass and mesh imparts tensile strength to the structure.