I cut the fiberglass heat wrap off my M36AC exhaust riser and found there was a crack in the weld where the raw water tube connects to the riser just before it enters the hump hose. When I tried to remove the riser flange from engine to take the whole assembly home, in some cases the exhaust flange nuts came off, in other cases the exhaust flange studs came out with the nuts. Is there anything potentially serious I should know about the studs coming out fused as they were to the nuts (I sprayed pb blaster on them first as was suggested in a earlier thread)? And once the nuts and studs were removed, the flange and gasket remained stuck to the engine. Does anyone have any suggestions on how to break the exhaust flange free without doing damage to the flang/engine.
Thanks-Joel S.
Joel Schwartz
s/v Get-A-Grip
1993 Catalina 36 Hull #1259
Newport Beach, California
The nuts being corroded onto the studs and the studs coming out of the engine flange is common and no big deal. You can put the studs with the stuck nuts back on as "bolts", or separate the nuts from the studs and then drive the studs back into the engine flange using two nuts.
If the riser flange won't separate from the engine flange, resist sticking a screwdriver between the two flanges. Try backing out all of the studs. A propane torch might help here. The gasket should allow for easy separation, but it might require a few hammer raps on the riser pipe.
Nick Caballero
Retired C36/375IA Mk II Technical Editor