Rusty/leaky exhaust elbow

Cardo

Cardo

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www.yacht-tinkerbell.co.uk
Joy of joys, the work never ends for a boat owner!

Yesterday I discovered some salty-like residue on the exposed bit of our exhaust elbow, near where the gas exhaust and raw water meet. I cleaned it off to discover a couple of small patches of rust. Having watched them with the engine running, it looks like there's a couple of small, pin prick holes where a bit of salt water can escape.

I've bought some of that "liquid metal" epoxy stuff to repair exhausts with. Will this stuff be suitable to patch up the holes, once I've cleaned away the rust?
 
It might get you a little time, but the fact is it's knackered.

Replacements are not cheap, however getting another one made at you local machine shop is a bit cheaper and depending on the materials used will outlast the replacement part.

Try a search, but not with the on site search engine, it's not that good. Google WBW and add you search phrase.

No doubt someone be along in a moment and give you the details.

Good luck and fair winds. :)
 
Our boat didn't have an elbow the exhaust was a straight pipe. It was mild steel and rusty so we replaced it with stainless, you could have an elbow fabricated in stainless. It does seem a common problem but I suppose the yacht builders have to watch costs.
 
If it's just leaking a tiny bit, either you're lucky or you've got a better made elbow than I have on my Bukh. Mine is made of some cast alloy, in its failure mode one day it looks a bit discoloured, the next day the casting disintegrates into pieces and releases the exhaust and cooling water into the engine compartment.
 
Cardo said:
Joy of joys, the work never ends for a boat owner!

Yesterday I discovered some salty-like residue on the exposed bit of our exhaust elbow, near where the gas exhaust and raw water meet. I cleaned it off to discover a couple of small patches of rust. Having watched them with the engine running, it looks like there's a couple of small, pin prick holes where a bit of salt water can escape.

I've bought some of that "liquid metal" epoxy stuff to repair exhausts with. Will this stuff be suitable to patch up the holes, once I've cleaned away the rust?
Click to expand...

Wont last you long , the corrosion is from the inside out , go see a local ( in land ) welder , had mine made from stainless off cuts , works just fine
 
Give it a little tap and you'll more than likely go straight through.

I took mine off last weekend with a view to decoking it, but once it was off discovered that all that remained was a tin foil thick remnant of the casting and a coat of paint. I'm pretty sure it was only the tube of coke within that had prevented it from failing.

All this, by the way, on an elbow which looked as good as new externally. If it was original, it's lasted 15 years though, which I suppose isn't bad.
 
We had same problem with our Perkins 4.108. The exhaust elbow disintegrated and although we spoke to several local fabricators none of them were prepared to take on the job. We eventually used Lancing Marine and from the very first contact these guys knew what they were doing. We sent what was left of the old one and they replicated it returning it with fixing bolts, gasket, etc. This was made in stainless steel - costing a little more than the modern Perkins replacement parts which did not fit. I would certainly recommend them.
 
Time for a new one. As others have said it is corroding from the inside so your little pinprick holes on the outside are indications that there is more coke and deposits than metal left. Try patching it to stop the water and gas spraying out but recognise its days are numbered.
 
James_Calvert said:
If it's just leaking a tiny bit, either you're lucky or you've got a better made elbow than I have on my Bukh. Mine is made of some cast alloy, in its failure mode one day it looks a bit discoloured, the next day the casting disintegrates into pieces and releases the exhaust and cooling water into the engine compartment.
Click to expand...

You're right there.

Mine disintegrated coming through the Small Boat Channel into Portsmouth. I had to leave the engine running until I got clear of the channel, by which time there was filthy mess in the engine compartment and cockpit lockers.
 
You might be able to fabricate one from standard black malleable iron plumbing items. This certainly works for the Bukh DV20. You need a 1 1/2 inch 45 degree M+F elbow, a 1/2 inch 45 degree elbow, a 1 1/2 by 1/2 inch Tee, a 1 1/2 inch M to M nipple and a 1/2 inch hose adaptor. All in, costs about £30. It doesn't last quite as long as the Bukh part, but you can afford to have a spare in the locker!

Neil
 
Cardo said:
Joy of joys, the work never ends for a boat owner!

Yesterday I discovered some salty-like residue on the exposed bit of our exhaust elbow, near where the gas exhaust and raw water meet. I cleaned it off to discover a couple of small patches of rust. Having watched them with the engine running, it looks like there's a couple of small, pin prick holes where a bit of salt water can escape.

I've bought some of that "liquid metal" epoxy stuff to repair exhausts with. Will this stuff be suitable to patch up the holes, once I've cleaned away the rust?
Click to expand...

We had a crack in the elbow. We had a weld which failed so we replaced it - call now and order as it could be upto a 6 week lead time.
 
Some years ago I lost power on my Perkins Perama 19hp engine. I removed the exhaust elbow for examination on the bench to discover ther was only a 10mm hole for the exhaust gases! Tried to clear all the coke and salt crystals and my screwdriver went through the casting as though it was butter. Fitted a new elbow, actually the Volvo Penta version, cheaper but identical apart from the paint and the engine was like new! I'm afraid it's time for a new elbow.......
 
As others have said, time for a replacement.
We had one go on a charter boat, 5 buckets of water in the engine compartment.
We patched it with ally foil, cut up and wrapped an oven glove around it and taped it in place. Saw us through until we got back to port where the new one was waiting.
They go catastrophically so don't wait.
 
Unfortunately, replacement is not an easy option at this time. We're travelling around Greece and have only just managed to leave our winter stop after numerous other delays. Sourcing a replacement would be difficult and expensive.

I've given the elbow a good few taps with a heavy screw driver and it seems solid. Though what the inside looks like I don't know. The leaks were right by a weld, though not on the weld itself. A bit like the leaks on our stainless water tank we just had replaced.

For the time being, I've placed a fair bit of the liquid metal stuff around the area by the weld, I'll have to keep an eye on it and see how things go.

Must say, I'm not particularly impressed, the engine's only about 4 years old. :rolleyes:
 
They are obtainable in Greece. I bought one for my Yanmar 3GM30F as an insurance spare last week in Leros. It was sent from Athens in two days and was quite a bit cheaper than the same item listed on many UK websites.
 
Please don't muck around, just replace it. I had a problem with the high rise exhaust elbow on my Volvo 201O last year, tried cleaning it for days, the end rubber caps were getting pressurised. In the end I realised the parallel channels of water and exhaust had corroded and were mixing. New was £400. I am now having a complete engine rebuild, the mechanic tells me there was definitely water in the engine, corrosion on the valves which are being replaced, new pistons,and he thinks it's down to the exhaust elbow problem.
 
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