installing an outboard moter

[crabbinmd]

I bought a 20' seahawk hull only. I have a 90hp merc to mount. After settingthe motor in place, i qickly realized that water is going to leak between the motor bracket and the stern on the outside of the hull where the through hull bolts go. Is there supposed to ge a gasket of some kind? Obviosley 5200 or 4200 will be applied to the bolts but that isnt going to stop the water from coming in.
help
Thanks in advance

[rj]

No gasket is used ,,bolt holes should be snug & sealed, 5200 is ok

[crabbinmd]

thanks for the info