What size and how long... transom board mounting screws

[wa_walleye]

I have a one inch thick transom board mounting below the waterline on a lund fisherman. How long to go thru board and secure to the transom? Thanks in advance for the input.

[ohiojmj]

I used 1.75" long screws on my .75" board and .125" counterbore to give me about a 1" engagement in the wood transome behind the .1" thick Al hull. I sealed screw heads and the backside of the board and put a filet of caulk around the edge.

[morris423]

I am presently installing a 3/4 x 3 x 14 1/4 on my 98 lund fisherman. You will find that the transom is not flat and you might need to do some shimming. I also plan to install a through bolt that I can install a nut from the access hole in the splash.

I am interested if you noticed this problem?

Morris

[Hot Runr Guy]

morris,
Rather than shimming the board away from the transom, place it in position, and "wack" it with a mallet, to impress the rivet & screw heads. Then, just drill or Dremel a recess at those locations.

HRG

[ohiojmj]

Originally Posted by Hot Runr Guy

morris,
Rather than shimming the board away from the transom, place it in position, and "wack" it with a mallet, to impress the rivet & screw heads. Then, just drill or Dremel a recess at those locations.

HRG

That's how I covered over the screws from a previous tranducer bracket with the new board. Sealed the screws, slopped the recesses with silicone, and all was covered and water tight.

If the transom is not perfectly flat, you could warm up the plastic board so it conforms. I would recommend having the board caulked and held tight to the transom to so the new screws are well sealed within the drill hole, behind the board, and around the screw head. I countersunk my board holes so I could easily seal the screw heads. Can never be too safe. I just saw a pic of a rotted 2008 Lund transom board where water obviously got in.