Exhausting stuff

To prepare for the new exhaust muffler fitment Anthony (aka Biscuit), who has replaced a muffler on a 47 before for Nordhavn Europe, kindly called and gave us the benefit of his experience. Summary was " it is a horrid job". He also advised us to cut an access hatch in the stack moulding behind the vent grille at the bottom to give decent access to the bolts on the lower flange of the muffler.

This was going to be messy - bits of fibreglass and dust floating around so the captain prepared for battle with lots of PPE involved (the hat was to avoid the strong sunshine - unlikely in Scotland we know but true!):

You could say that he looks way better than normal but that is a little unkind. Accurate but unkind. By the way, the protective gloves were added later - just in case any health and safety types are reading this....

The hint from Ant was a good one as you can see from the "after" picture below:

giving decent access to the bottom of the muffler and the dreaded bolts.

The Nordhavn Europe, Harco and DHL folks did a good job getting the new exhaust to us in a week, and it kind of filled up the saloon floor nicely:

The foot ruler laying on top of it gives you an idea of scale. Yes, it is BIG. Heavy too - 50 odd kilos to lug around. The crew was a little unhappy at the new addition to the saloon furniture.

There had been a big debate on ordering a stainless or another carbon steel replacement. The captain was tempted to the stainless version especially as we'd been told that it wasn't significantly more expensive than the standard unit. Problem was a 4 week manufacture time and then shipment to us. Not ideal - 6 weeks in Greenock. It also messed up some autumn plans. We also had no proof of how much longer a stainless muffler would last - stainless does not like the temperature variations it would be exposed to in a muffler longer term and several "engineering" folks advised against one.

The clincher was advice from the Nordhavn Europe folks on price. The stainless unit was around 3 times the cost so, we opted to take the ex-stock standard unit and we will give it a serious TLC regime. They seem to corrode from the outside in mainly with water being held against them by the lagging wrap stuff. As the new wrap is way way better then the original and fitted via straps and D rings, we can remove it when the boat is not being regularly run in the winter to prevent it trapping moisture against the metal. We will also give the muffler an occasional paint job. If it lasts 10 years like the original one which was totally ignored, that will be OK.

With the help of the very good guys from Swordfish Marine in Holy Loch, the old muffler was removed leaving a big gap between the two pieces of pipe:

Having a crane makes dropping in the new unit so much easier:

So, with the muffler in place it was good to fire up the engine again - mainly to help cook the new paint on it not just to check for leaks.

A fun day was then spent touching up the paint on it and covering it with the new wrap from the excellent T and M Supplies guys. The new silencer wrap is just miles better (OK. Kilometers better for some readers) than the original stuff. It fitted very well too:

 

The only challenge was that the original wrap on the flanges had to be reused and it was in a very sorry state:

So, it was temporarily wired in place and will get replaced this winter (T and M's workload permitting that is)

We very happily refitted all the grilles and recovered the RIB which had been launched to allow proper working space. Good to know that the boat is ready for sea again. Just need the right weather now....