Thanks Gamera,
I'm glad you like the Canadian theme eh!
Raualduke,
The sandbags are sugar packets cut on two sides and turned inside out. Not all packets are the same and any that are at a angle instead of square when turned inside out are tossed. Next Millputt is mixed and cut to fill the sandbag, a small stick was used to pack the putty into the corner. Then the cut side was trimmed with scissors close to the putty. Finally the top was tied with suitable string and the top trimmed. The open side can be used to pack the putty further or add / remove some. Last step is to press the seam into the side with flat nose pliers, if the 'open' side looks good after pressing in a seam then save it for 'top' use, that is not all will look good on both sides.
Keep rows flat on top, press a indentation in the sandbag if a 'top' is resting on it from the next one. After the row is done flatten further with a popsicle stick, secure stick if possible. Seams may need to be redone once its set in the base. I used white glue to secure, along with some of the Millputt that came out of the open side. Two rows is a good time to take a break and let set further, more risks the lower rows flattening or bulging out.
Almost fast as filling & tying a real sandbag! After a few dozen it does speed up a bit.