Surely a hole in the hull wont sink a boat!

Mar 2, 2019
613
Oday 25 Milwaukee
I'm also an owner of an Oday 25 . No cored hull. I have the same transducers . Surprisingly it still works just fine.
My view ? Either leave it alone or take everything out and have someone else fiberglass it in completely. Your tentative solution leads me to believe you don't have a tremendous amount of fiberglassing experience and you are very anxious to get on the water . Recipe for tragedy. I sail Lake Michigan as well .When our boats are pounding in to the waves coming from the west as you are trying to return to the safety of shore ,then the leak will appear..I realize you may not agree or like any of this ,you however asked .
 

Ward H

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Nov 7, 2011
3,797
Catalina 30 Mk II Cedar Creek, Bayville NJ
For $85 to $95 you can buy a Raymarine depth or speed transducer that fits in a 2 1/8" hole. Defender or Amazon can probably have it to you on Friday.
Pick up a tube for 4200 or Sik-I-Flex 291 and you can have it installed in less time than fiberglass can set up.
Maybe you won't use it for a while but you will be properly filling the hole with something useful down the road.
 

JRacer

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Aug 9, 2011
1,374
Beneteau 310 Cheney KS (Wichita)
For $85 to $95 you can buy a Raymarine depth or speed transducer that fits in a 2 1/8" hole. Defender or Amazon can probably have it to you on Friday.
Pick up a tube for 4200 or Sik-I-Flex 291 and you can have it installed in less time than fiberglass can set up.
Maybe you won't use it for a while but you will be properly filling the hole with something useful down the road.
Better option than the "Quick and Dirty" and possibly catastrophic!
 
Oct 26, 2008
6,314
Catalina 320 Barnegat, NJ
Tapering the repair area isn't about making it pretty. It has to be done to make it secure.
 
Jan 19, 2010
12,665
Hobie 16 & Rhodes 22 Skeeter Charleston
For $85 to $95 you can buy a Raymarine depth or speed transducer that fits in a 2 1/8" hole. Defender or Amazon can probably have it to you on Friday.
Pick up a tube for 4200 or Sik-I-Flex 291 and you can have it installed in less time than fiberglass can set up.
Maybe you won't use it for a while but you will be properly filling the hole with something useful down the road.
It is not the transducer that is suspect... it is the through hull flange
 
Sep 24, 2018
3,601
Catalina 30 MKIII Chicago
The current fitting is held in with what appears to be 5200. I couldn't pull it off by hand.

apering the repair area isn't about making it pretty. It has to be done to make it secure.
In most cases you only have access to the outside to do repairs. I totally agree with tapering as it increases contact between the existing and new fiberglass. A repair such as this doesnt make sense to do from the outside since gravity would be working against you. In addition a large patch on the inside would have far more contact than tapering. For the record I think tapering is a waste of time in this scenario but I will do both tapering and a patch.
 

Ward H

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Nov 7, 2011
3,797
Catalina 30 Mk II Cedar Creek, Bayville NJ
One the Raymarine transducer thru hull fitting there are two flats for a wrench. I used this type wrench:

https://www.amazon.com/Superior-Too...sink+wrenches&qid=1561680597&s=gateway&sr=8-7

I used a multi tool to split the lock nut in three places, then a flat bladed screw to pry the pieces off.
Then I used the adjustable wrench to work the thru hull back and forth until it broke loose enough to hammer it out.
Cleaned up the old sealant an old credit card and putty knife and acetone. Then installed the new one.