Tilt your outboard up and apply downward pressure to the lower unit. Any visible movement or "smiling" (the gap opening between the motor and the transom) is a red flag.
Butter the new core with thickened epoxy or polyester resin, clamp it into place, and glass over it with layers of 1708 Biaxial Cloth .
Chisel out the rotten wood. On older Gradys, this often turns into "mud". grady-white-transom-repair
Use a plastic mallet to tap across the transom. A sharp "ping" is good; a dull, hollow "thud" indicates delamination or wet wood.
Only use Marine Grade Plywood (like Okoume or Meranti). Never use pressure-treated wood, as the resins often won't adhere properly. 2. The Composite (Coosa Board) Upgrade Tilt your outboard up and apply downward pressure
The only way to be 100% sure is to drill small exploratory holes from the inside . If the shavings are dark, wet, or smell like mulch, the core is gone. 🏗️ Repair Options: Wood vs. Composite
Restoring the Legend: A Guide to Grady-White Transom Repair For many owners of classic Grady-Whites, the boat is more than just a vessel—it’s a family heirloom. However, even the "overbuilt" legends of the 80s and 90s aren't immune to the "dreaded rot." If you’ve noticed stress cracks around the motor mount or a slight "flex" when you trim the engine, it might be time to face the transom. Chisel out the rotten wood
Repairing a Grady transom is a major undertaking, but it's the difference between a "total write-off" and another 20 years on the water. 🛠️ The Assessment: Is It Actually Rotten?