Pull slightly on the top left corner of the form, top left for the Form Handler standing or kneeling inside the igloo, until the form is bowed and the pressure is transferred through the form and across the pole to the lower right corner of the form.
Pack the snow into the corner on the inside of the form with one push directly into the corner created by the form, the previous block and the floor or layer below. This push shouldn’t break the other blocks, but should move the inside form about 1/8 or 1/4 inch towards the inside man. A couple more pushes and the snow is packed. It is important that subsequent pushes after the first don’t move the form or fracture the snow.
The next shovel of snow should be placed in the corner created by the outside form panel and the two snow blocks previously mentioned. This is the critical snow to be packed because it adds support if done correctly. Push into the outside corner the same as you did on the inside corner, but hard enough to spread the form about 1/2 to 3/4 inch. Hold this pressure for a few seconds.
If upon releasing, the snow gives and the form comes back together, push again and have the shoveler place another amount of snow on your hand and against the outside panel. It should hold when you release this. If it doesn’t, repeat until it does.
This preloads pressure into the U bar and the entire form making the form more rigid. The pressure used to do this is greater than the pressure used to pack the rest of the block, possibly 10 to 15 pounds of pressure.
During this process, continue to hold the pressure on the top left corner of the form. After the lower right corner is complete and the form is preloaded with pressure, you can release the pressure on the top left corner. You will only need to hold a slight pressure after this to steady the form.
After completing the preloading on the corner, put in one shovel full of snow
and pack it.