Why did Sam have trouble getting tannic acid to tan his deer hide and how did he finally get it in "Frightful Learns Her ABCs"?

Sam knew that he needed tannic acid and that water and oak would produce it. He had plenty of water and oak, but not a container big enough to put the deer hide into. Then he noticed a old sump after it had rained. He was able to use that oak stump to soak his hide.