Brush on?

I seem to be trying every sort of mould making material this year. The  (red and yellow) re-meltable stuff, Pinkysil (pink) and now today a brush on product (blue) called Gelsil. I haven't used this type of stuff before. It's a 2 part mix. On opening the tub and trying to dollop out the white part I wondered about the description 'brush on'...imagine beating egg whites for a meringue and adding bubble gum and you'll get an idea of the consistency, much much stiffer than bathroom silicon. You need  good cake / concrete mixing arm to combine the two parts. The 'brushing on' step was more like persuading, trowel-ing or pushing action. Though I guess for a term to use brush on is OK.
So today I set up the branch with a surround of clay and applied the first layer. I used half a kilo for one side. It takes between 6-12 hours to set so i'll come back tomorrow for the next layer which I may do in a cheaper bathroom silicon.