A barrel that had peeled

and its pitch remained (wine barrels were lined with pitch; in this case part of the earthenware wall of the barrel had fallen away, but the inner coating of pitch remained intact and held the barrel's shape),

and similarly fish brining vessels

that [are sealed with] gypsum until the edge (i.e. the mouth of this container is plugged with gypsum and the plug, like a cork in a wine bottle, does not protrude over the top edge of the container),

Rabbi Yehuda says

they do not protect (as he holds the cover must be over the container, not just in it)

and the Sages say it protects.

פרק י משנה ו

A barrel that develops a hole

and is plugged by sediments

they have protected it.

If one plugged it with a vine

[it will not protect] until one plasters it from the sides.

If there were two [vines used in this plug]

[it will not protect] until one plasters it from the sides

and between one vine and the other.

A board

that was placed over the mouth of a tanur

if it is plastered from the sides

it protects,

if there were two [boards]

[it will not protect] until one plasters it from the sides

and between one board and the other.

If they were made with [an adhesive made from] thornwood shavings (some say this refers to tenons, a means of joinery in which one board has tenons, pieces of wood that protrude like a plug from one board and that fit tightly into sockets, called mortises, in the adjoining board; yet others interpret this to refer to joinery using dowels in holes drilled in each board)

or with [an adhesive made from] reed-grass shavings (some say say this refers to strips of reed grass that were used to bind the boards together; others say this refers to a rabbet joint, where a step-shaped recess is cut along the edge of one piece of wood forming a match to the edge or tongue of another piece)

it is not necessary to plaster

from the middle.