Exhaust Elbow

[Storm Dragon]

The exhaust elbow on my Volvo 2030 became blocked with deposits and this prevented water cooling of my engine, but as there is nothing wrong with the exhaust elbow apart from being blocked by deposits, is there any way these deposits can be removed by submerging the elbow in some sort of solution?

 

[Allergy]

On my 2020b, I've carefully used a small chisel & hammer to shift the deposits & supplimented it with a rotary wire brush to get alot of the carbon out. A very mucky job, so you'll need a dust mask etc. It lasted a few more years before I finally replaced it with a new one from Keypart.

 

[skip50]

On my VP2003,with a similar problem, I immersed it in Brick and Patio Cleaner from B&Q, or it might have been Travis Perkins. Lots of fizzing etc. I immersed it for a few minutes, then removed, rinsed, cleaned some of the crud off and repeated until satisfied. It is a mild acid solution so use suitable protective clothing, goggles etc. At your own risk etc.

This was as a result of previous threads on here which you should be able to find.

 

[PetiteFleur]

On my previous boat with a Perkins 2020(same as the VP 2020), the elbow carboned up and I started tyo clean it the chisel just went straight through the cast iron so had to get a new elbow - surprisingly the VP identical elbow was cheaper than the Perkins!

 

[Seatrout]

see http://www.ybw.com/forums/showthread.php?359725-Exhaust-Elbow-Refurb-Advice&highlight=exhaust+elbow+refurb

 

[pagoda]

On my VP2003,with a similar problem, I immersed it in Brick and Patio Cleaner from B&Q, or it might have been Travis Perkins. Lots of fizzing etc. I immersed it for a few minutes, then removed, rinsed, cleaned some of the crud off and repeated until satisfied. It is a mild acid solution so use suitable protective clothing, goggles etc. At your own risk etc.

This was as a result of previous threads on here which you should be able to find.

And for what it's worth, if the elbow is clogged up, there is a high probability the exhaust manifold cooling channels are in the same state. If there is a removable cover (order any likely gaskets first) then take it off and thoroughly clean out the inside . Horrible job, but worth the effort. The apertures where the water exits the manifold are prone to calcifying, but a smallish rotary wire brush will help sort that. It depends on access in the engine area mind you. You might need to take off the entire exhaust from the head to get at it.

Graeme

 

[nigelmercier]

On my previous boat with a Perkins 2020(same as the VP 2020), the elbow carboned up and I started tyo clean it the chisel just went straight through the cast iron so had to get a new elbow - surprisingly the VP identical elbow was cheaper than the Perkins!

You were lucky then, you had a weak-spot. I did the same with a screwdriver.

 

[cryan]

To clean salt deposits you should use a mild acid. Fortunately combustion products from diesel (the black stuff in your exhaust) will form a mild sulphuric acid when mixed with fresh water. Immerse the whole thing in a bath of water for a while, perhaps bubble some air through it if you have a small compressor handy. After a day or so it should be fairly easy to clean the stuff out with a boiler tube brush or similar type brush.

 

[nigelmercier]

To clean salt deposits you should use a mild acid...

How does that work then?

 

[pagoda]

How does that work then?

I think the "salt" deposits concerned are mostly carbonates deposited from the sea water at fairly high temperatures. These cause quite serious problems in outboards as well.
They are easy to get rid off with mild acids - vinegar / citric , probably even bulk Coca Cola.
Take any zinc anodes in the system out first though - or they will vanish as well as the deposits!
Arranging a closed loop (bucket system) to circulate on takes a bit of thought, but is not really difficult.
Don't do this for too long, and avoid with engines with alloy heads....

 

[nigelmercier]

I think the "salt" deposits concerned are mostly carbonates deposited from the sea water at fairly high temperatures...

Makes sense, thanks.

 

[cryan]

There are acid cleaners available for flushing seawater systems on a commercial scale (unitor, drew ameroid )but for a small item this is not really a sensible choice. However as I stated the exhaust deposits on the gas side of the manifold and elbow will form a mild sulphuric acid solution by being dunked in fresh water. In fact on Merchant Ships this is how you clean exhaust components such as turbo rotors. They use a rougher fuel with higher sulphur levels so the solution is stronger and it cleans quicker but it does work with marine gas oil (red diesel).