DrGonzoMIA

Ok thankyou for advice. It's been in canal for some time I think but will deffo check.

Thankyou for that. My exhaust outlet is just below the waterline on port side. I can as mentioned tie it to bank to lift above waterline in case of emergency. Maybe I just need to fit a one way valve when it's out the water and not worry about it too much ?

If I do add the stainless goose neck will the exhaust be powerful enough to blast water around it without any other modifications? I'll try use slower bends for least resistance. I wouldn't imaging any backfilling water into the water lock would be an issue as currently its the canal that's back falling into it ?!

Cool thankyou. Feel like I'm getting somewhere. The exhaust being below the waterline has always concerned me to be honest. I had to change a perished pipe a while back as it was leaking on the exhaust outlet. I had to ratchet strap the boat to the bank to lift the exhaust above the waterline to change the hose. I was hoping to find a one way valve but no. I do need to sort this somehow when it's out of the water next

True

That looks similar to what I propose. If the water lock was above the waterline it's not doing its job? It's intended to let water run down into it when engine off

Thankyou. This was what I planned to do. System already has a small anti syphon loop just after the heat exchanger. I wanted to add a 76mm stainless goose neck after the water lock. Would that need to be vented ?? I've looked at many a diagram on the Internet. Mainly Vetus. But also find conflicting information from so called experts.... Cheers

Hi all, hope everyone is well. I bought a big ol' 40ft Steel Motor cruiser last year to live on. Built in 1979 as far as I'm aware and moved from the sea to canals. It has a ginormous Leyland 6/98 5.7l diesel engine. Haven't really been anywhere in it yet but want to make a start getting it a bit more refined. I appear to have a leak on the Vetus waterlock so got to googling exhaust systems and I'm not sure if my current setup is very good. Please see rough sketch I have attached which is not far off what it looks like currently. Biggest concern is water backing into the engine once off. I've had an idea of getting a 76mm stainless steel exhaust section from a car to create a goose neck after the waterlock. Would that be a good idea ?! Vetus sell a goose neck but it's a ridiculous price and out of stock everywhere. Many thanks for any help or wisdom you can throw my way.

Sorry. I kinda confused the issue...internal diameter of roof collar is 5". I got hold of some decent 15mm rope which fits quite well. I like the idea of having the flue just short of the collar so the sealant can be banked down to try and direct moisture back into the flue to be burnt off instead of out and rotting the chimney base.

Cheers all. It's a 6" roof collar and a 4" pipe that goes through (at a bit of an angle) I have a stainless pipe section so will do as you say and leave a couple of mm protruding. Mines not actually a narrowboat but a river cruiser jobby so I'm pretty screwed with bridges anyway 😅

Just in regards to installing a flue through a roof collar. Should the flue pipe be cut flush with the top of the roof collar. And the the chimney be fit over the roof collar. Or should I take the flue pipe up to the same height as the top of the chimney ? Cheers

Yeah I had that on a Ford Ranger bonnet. Had apparently been used on railway work and sparks had sunk into bonnet and rusted. This just seems like a thin metal layer its bizarre. I'm just worried about stripping off this top layer if it's anything structural. If my steel is 5mm thick, by the time I've sanded this back it will be about 3 !?

So started sanding down a few areas which appear to be causing me some leaks after the heavy rain recently. However I'm slightly confused by what I'm finding. There appears to be a metallic coating (which seems rusty) then a green coating, down to what looks like a red oxide primer and then bare steel. I can't figure out why there would be a metal top coat though?? Anyone have any answers at all ? I can only assume the top paint has some kind of metal in it ?

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Just a note on this. I found a place called fluepipesdirect.co.uk They have a reducer to go from 5" to 4" and made me a nice stainless offset and 1m straight length. Really happy with quality and chap i contacted on email called Dave was spot on. They fabrictate stuff by the looks so could probably help if anything out of the ordinary needed. Good prices too (i dont work for them btw !) Saved me getting custom chop work done anyway !