Punch Plates Options

[tlcarrig]

Can anyone here give me a definative reason for the use of a punch plate in a sluice or rocker box. I can see using one in a highbanker or dredge but i don't see the need for one in a sluice. Am I off base here or am I thinking streight?

[russau]

using a punch plate helps screen off the larger rocks/gravels and keeps the finer material in the sluice from being displaced from the bigger gravels. Leonard has a good example on one of his videos or Dr. Sluice and his sluicing methods using a screen at the front of his sluice to remove the bigger gravels. and he does real good ussally sluiceing!