Can I use 1 larger rectangular backing plate?

[ttownthomas]

My Boat (1972 bertram 25) had 2 old through-hull transducers fairly close to each-other. I enlarged the holes and am replacing them with a new transducer and a seacock. Almost all the through hull backing plates I see are round. Is a round through hull more dependable or safe than a rectangular one with rounded corners?

I was thinking about making 1 rounded corner rectangle out of okoume ply wood glassing it thoroughly and using it for both through hulls.

Is there anything wrong with this strategy?

 

[gm280]

Not exactly sure what you are asking about. However, if you can make your new backer plate out of aluminum, it would offer a rot free setup. Either way, make sure any through hull is water tight to fight against future leaks and rot. JMHO

 

[ttownthomas]

I was asking if there is a reason to make two separate round backing plates instead of one larger rectangular one with rounded corners.