What’s everybody using to seal copper head gaskets with water jackets. Have been using smear of threebond on head and block around all water passages with spray of copper coat on both sides of gasket. Had good luck but the threebond is a pain to clean up and some say it will not allow the gaskets to totally seat causing leaks in the combustion chamber. O-ring case block with recover groove in aluminum heads. Hearing just the copper coat or the blue hylamar spray and skip the threebond.

You’ll probably have 9 out of 10 say a light to medium coat of spray copper coat. And if your head are angle cut make sure you check for the uncut places on the ends up by the intake. A small bead of silicone will seal those up so no oil gets out of the valley area.

2-3 coats of Copper coat is all I used. I would get a few drips the first couple of heat cycles until engine was hot but would go away after I re torqued the heads.
Tried a little silicon around the water passages once but was a PITA when having to pull the heads for whatever reason

I do the same as Steve. 3 coats of copper coat, letting it dry completely between coats. Have to use a pry bar to get heads loose from block if I pull it apart.....no leaks ever....