Mouse Over to Zoom
Click to Enlarge

GROCOSeacock Backing Blocks

Prices from $58.99 - To $101.99


In stock online.
Model # 15939275 | Mfg # BB-2UPC # 742985170148


Product Overview

Create a secure seacock installation with these rigid backing blocks.

Flanged seacock installations improve with the use of a backing block between the valve flange and the hull. Each backing block size fits multiple seacock sizes. Backing blocks include threaded inserts that press into the hull side of each block, into the holes that match the seacock flange. The 1/2" thickness is rigid enough for a secure installation, but flexible enough to conform to minor hull curvature. Backing blocks will not absorb moisture.

NOTE: Seacock shown for illustration only (sold separately).

Key Features

  • Each size fits multiple seacock sizes 
  • Threaded inserts included to match the holes in the seacock flange
  • Rigid 1/2" thickness is flexible enough to conform to minor hull curvature
  • Will not swell or absorb moisture
  • Made from an environmentally-friendly PVC foam specially formulated for marine applications

ModelAccepts Seacock SizeDiameterThreaded Inserts
159392673/4" & 1"4 9/16"5/16"-18
159392751 1/4" & 1 1/2"5 3/8"5/16"-18
159392832" & 2 1/2"7 1/4"3/8"-16
159392913" & 4"9 1/2"1/2"-13


The West Advisor articles have answered boaters' questions and provided solutions to boating problems for more than 20 years. West Marine has compiled one of the Web's most comprehensive collections of technical boating information articles.

Related West Advisor Articles


Product Q & A