1959 Hiliner 16'; advice on small crack in top of transom

so just picked up the boat (no motor), hasn't seen water in about 25 years..i got a 1969 50hp merc running i had from another project and set it up. when home from my first trip out, i see a long crack in the transom, i'm assuming from the weight of the motor back there. i'm guessing it happened from trailering the unit to and from, and not from the trip down the connecticut river. so i invest in a "transom saver" shock absorber type from cabellas and fit it to the motor and trailer for towing, and i sand down the cracked area, dig at it a little, and start applying some polyurethane to seal it up. it is very solid, and doesn't have any flex.

am i missing anything and should i be doing anything else to prevent this or repair it? also its the original trailer i am told, and although it is sound, its nothing like the sturdy new trailers they make now adays..

i can't find much info on the older hiliners, although it should just follow the same rules as other wooden runabouts, right? do i need additional bracing or a plate to help distribute the weight from the motor instead of just the two circlular outboard clamps & two lower bolts? i am using a 3/8" spacer on the outside of the transom as shown, but its just to clear the wood trim on the transom water line.

 

Nice looking Boat! I would run the thing and watch it. Looks like plywood transom but if that thing hasn't seen water in that long I'm surprised nothing worse hasn't shown up. That Merc is heavy but your boat should handle it no sweat. You are doing the right thing in keeping water out of little cracks that show up.

 

If I am seeing it correctly, it appears the crack formed between the layers of the plywood veneers of the transom? If that is the case it is a sheer failure of the bond between the plywood layers.

If for some reason the adhesive bond between the veneers is breaking down (not unusual for old weathered plywood), than you need to do something to keep the layers bonded together.

I am not sure if there is a practical way to inject adhesive into the wood, but I would consider installing a pattern of bronze screws at about 2" spacing from both sides of the transom. Install them "wet" with adhesive, and than you can bond a doubler layer of wood over them to hide the heads. If done carefully it should look good, and will be stronger than the original design.

Good luck with it.

 

silicon bronze wood screws are the solution.