Search And Replace Only Replaces One Char Per Field

I am attempting to find quotes (") in a column and replace with the string '--THIS-WAS-QUOTES--'. Right now my script only converts the first quote it finds in the description column, converts to the string and moves to the next row leaving the other quotes as they were. Below is my query script

DECLARE @find varchar(8000),
@replace varchar(8000),
@patfind varchar(8000)

SELECT @find = '"',
@replace = '--THIS-WAS-QUOTES--'

SELECT @patfind = '%' + @find + '%'

UPDATE Incident
SET description = STUFF(convert( varchar(8000), description ),
PATINDEX( @patfind, description ),
DATALENGTH( @find ),
@replace )
WHERE description LIKE @patfind