I can't tell if this is a wet exhaust
system or dry, so I'll respond to both.
1. There has to be a flexible coupling or hose between the exhaust
system and the engine
, because the engine
moves on its flexible mounts.
2. If the exhaust system is wet, with raw water
from the heat exchanger
being injected into the exhaust gas right after the exhaust manifold, in a mixing elbow
, the exhaust system temperature will not exceed 70 Celsius and there will be no melting problems with solder or brazing, However, the salt water
and warm gas combination will eat through the solder or brazing, and eventually even the copper, usually causing multiple pin hole leaks
before total failure with joints coming apart. Not good.
3. If this is a dry system, with no water
injection, wrapping the components will increase their temperature and increase the probability of the joints failing. Exhaust gas temperatures range from 500 to 1000 Celsius. In addition, anything that this system touches will have to be insulated from it.
These are some of the reasons why boat
builders do not use copper plumbing
pipes and fittings to make exhaust system. In spite of the cost, you're better off installing a real marine
exhaust system than risking your boat
and your life with this amateur installation
Let me know if you need more information or input on this.