Transom void

Jul 31, 2020
2
Macgregor 25 Redondo
1977 Cat22 transom issue. Prior owner had two U-bolts mounted high on each corner of the transom. The one on the starboard side is fine. The one on the port side was loose and the fiberglass indented. After removing the U-bolt, I could not see any part of the 1/4” wooden transom core inside the mounting holes. I used a 12” plastic cable tie to see how much of the wood was gone. It went in all the way to the bottom and half way to the center of the transom. I estimate that 15% of the transom on the port side is void of any wood core. Can I fill this void with a resin or foam? Luckily, there is good wood in the motor mount holes. The inner and outer transom skins are 1/4” thick and show no damage. I would appreciate any insight as to the magnitude of the problem and advice regarding a repair.
 
Mar 29, 2017
576
Hunter 30t 9805 littlecreek
Closed cell marine spray works great to fill voids take it easy when spraying as it will expand and miss shape or blow out the fix
 
Jul 31, 2020
2
Macgregor 25 Redondo
Thank you for your suggestion. Is there a particular brand that you would recommend? I tried putting a wire in the void and it would not go in. I’m thinking now that the transom wood might be delaminated from the fiberglass. Would a delamination be repaired with foam? Thanks again.
 
Sep 22, 2018
1,869
Hunter 216 Kingston
1977 Cat22 transom issue. Prior owner had two U-bolts mounted high on each corner of the transom. The one on the starboard side is fine. The one on the port side was loose and the fiberglass indented. After removing the U-bolt, I could not see any part of the 1/4” wooden transom core inside the mounting holes. I used a 12” plastic cable tie to see how much of the wood was gone. It went in all the way to the bottom and half way to the center of the transom. I estimate that 15% of the transom on the port side is void of any wood core. Can I fill this void with a resin or foam? Luckily, there is good wood in the motor mount holes. The inner and outer transom skins are 1/4” thick and show no damage. I would appreciate any insight as to the magnitude of the problem and advice regarding a repair.
You might want to read some of the repair/rebuild threads in the Cat 22 area.