I was thinking same thing. Make sure its low expansion and leave box lid open till it cures.
George's idea with sonotube is great idea, I've shipped parts in carpet roll tubes as well.
I just finished doing our fence and sonotube are cheap, different diameters and usually priced by the foot.
10" sonotube was under $2/per foot.
You may wanna check with Canada post to see the max amount it can be insured for.
