Effects of using a single skinned chimney....

[Guest]

Our chimney I've just noticed is rotting through at the base where it sits on the collar.

 

Single skin ones I notice are cheaper, so what is the difference? Will a single skin one suffice???

[BargeeSpud]

I wouldn't have thought that whether your chimney is single or double skinned would make a lot of difference to it's susceptibility to corrode. Aren't the double skinned ones designed to divert the condensed tar back down the flue rather than over your roof?

Edited May 9, 2013 by Spuds

[pete.i]

Hi

 

My chimney is single skinned but I have a stainless steel sheet inner that is wrapped / rolled to fit inside the collar. The reason that the double skin is there, as Spuds quite rightly points out, is that it diverts the tar and crud back down the chimney rather than down the outside of the boat or down the outside (and hence into the boat) of the flue. I'm not sure whether it is better to have a double skinned one, because the inner skin is attached to the inside of the chimney whereas my rolled piece of stainless steel is not attached, or not. All I can say is that I do not get tar and crud running down my boat so it must be working and it does mean that I can buy the cheaper single skinned chimneys because they still rot at the base whether they are single or double skinned, again as Spud rightly pointed out.

 

Pete

[Guest]

Cheers ~ I hadn't envisaged less or more susceptibility to rot but rather was curious as to the perceived benefits, as I vaguely recalled there was some but couldn't recall what the claims are.

[Grace and Favour]

Cheers ~ I hadn't envisaged less or more susceptibility to rot but rather was curious as to the perceived benefits, as I vaguely recalled there was some but couldn't recall what the claims are.

I thought that a double skinned bespoke chimney in Stainless steel would be worthwhile.

 

Two long winters later - it, the roof casting, and my paintwork, are all in excellent condition.

 

Highly recommended

[Kae]

You definitely want to avoid the tar on the roof if you can help it. Dili is badly stained the entire length of the roof on the port side hand rail and down the side where the cut-out is.

I'll be putting an insert in the chimney for next winter!

[Guest]

OK - I'm convinced, double skinned it is - not sure I want to go to the lengths of a SS one though, OK I guess they will last longer.

 

I guess this one would have lasted a bit longer had it not seized to the collar last year and we couldn't get it off when not on the boat and it had to stay on all winter exposed to the elements whereas we normally have the galvanised cap on when not using the fire.

 

Now its rotted I will just butcher it to get it off.

[BargeeSpud]

OK - I'm convinced, double skinned it is - not sure I want to go to the lengths of a SS one though, OK I guess they will last longer.

 

Check out the cost of an inner galvanised liner + single skin chimney before commiting to a fixed double skinned chimney, It might be slightly cheaper. For example: double skinned black 6" x 18" chimney from MC £47.46. Same but single skin + liner £45.22.

 

Not a lot I know, but the liner will last longer than the chimney & the double skinned ones fit to your collar could be dependant on whether your flue is centrally located within the collar. Mine is offset, so a double skin chimney won't fit properly.

 

Sorry if that's confused things!

[onionbargee]

a goods stainless one should last indefinitly, whereas galvanised ones corrode away in a couple of years. Pretty sure a s/s one will be more economical in the long term. A double skinned one will also insulate the chimney, and get you a better draft.

[BargeeSpud]

a goods stainless one should last indefinitly, whereas galvanised ones corrode away in a couple of years. Pretty sure a s/s one will be more economical in the long term. A double skinned one will also insulate the chimney, and get you a better draft.

 

Hate to contradict, but galvanised products will last a very long time, that's the whole point of galvanising. I agree that SS will be more economical in the long term, but I'd still consider a single skin SS chimney with a galvanised liner for the reason I outlined regarding the flue's position within the collar, whether it's central or not. That is what I have set up at the moment.

 

What I was describing was a single skinned chimney with a separate galvanised insert (liner). This will also insulate the chimney & give a better draw, just as a double skin one will.

Edited May 9, 2013 by Spuds

[Guest]

a goods stainless one should last indefinitly, whereas galvanised ones corrode away in a couple of years. Pretty sure a s/s one will be more economical in the long term. A double skinned one will also insulate the chimney, and get you a better draft.

The chimney on the boat was the one on it when we bought it three years ago and I doubt it was any where near new then.

 

If it had't seized in place it would have lasted even longer.

 

I need to be more stringent about ensuring the collar has something better on it than what was advised on here before it is put in place and that is taken off when not needed.

 

Things of course would different for somebody who lives of aboard.

Edited May 9, 2013 by The Dog House

[bizzard]

I don't waste my money buying fancy chimneys, whatever type, from chandlers.

The best and cheapest way and to prevent goo oozing out from between an overlapping chimney and collar is to visit a heating or air conditioning company. They usually have stocks of tubing offcuts brought back from jobs and what you want can be had for a drink, couple of quid or even for nought.

I'd choose a length of s/s tubing that fits loosely INSIDE the collar aperture and seal it in lightly with silicon so if you need to remove it for a low bridge or it gets hit it will just lean over. No more goo running down your boat.

[bizzard]

I don't waste my money buying fancy chimneys, whatever type, from chandlers.

The best and cheapest way and to prevent goo oozing out from between an overlapping chimney and collar is to visit a heating or air conditioning company. They usually have stocks of tubing offcuts brought back from jobs and what you want can be had for a drink, couple of quid or even for nought.

I'd choose a length of s/s tubing that fits loosely INSIDE the collar aperture and seal it in lightly with silicon so if you need to remove it for a low bridge or it gets hit it will just lean over. No more goo running down your boat.

If you get a long length you can make various different length chimneys to suit the height of bridges on your cruising route. A chimney change of this type can be performed without stopping in about 10secs with a tube of ordinary cheap Silicon which is just as heatproof as the fancy red coloured expensive stuff, once cured.

[loubyscooby]

Made me laugh Bizzard. Images of a boat with numerous chimneys on the roof and discussions about which one is best suited for the next bridge - could be the start of a new game whilst cruising.

[bizzard]

Made me laugh Bizzard. Images of a boat with numerous chimneys on the roof and discussions about which one is best suited for the next bridge - could be the start of a new game whilst cruising.

Its no use wasting time discussin and dithering about when a low bridge is looming up fast. Instant decision and ACTION! is whats needed to change em under way.

[by'eck]

I had a lot of goo regularly leaking out of the bottom of my single skinned chimney. When I fitted a coolie hat to it though, it stopped.

 

Guessed it somehow reflected heat back into chimney and so reduced the condensation that created the goo, unless anyone has a better suggestion.

[bizzard]

Burning your stove fiercely all the time will keep the flu and chimney hot enough to prevent goo oozing out caused by condensation.

Alternately chuck the daft overlapping chimney overboard , fit a double skinned one which unless they fit accurately won't work anyway and you've got money to burn, do the 100% perfect cheap version as in my post above. You can always stick bits of naf brass embellishment on it if that's what your mainly all after.

[peterboat]

aahh and you were the person that adjusted his stove with bricks so that you did not use as much fuel? 2 bits of coal does not make a blazing fire unless they are big bits I supose? I have a double skinned chimney which are galvanised for both my stoves I also filled them with insulation to help the draft the bubble one is never a problem but the solid fuel one can stick on the collar the joys of boating

 

Peter

[bizzard]

aahh and you were the person that adjusted his stove with bricks so that you did not use as much fuel? 2 bits of coal does not make a blazing fire unless they are big bits I supose? I have a double skinned chimney which are galvanised for both my stoves I also filled them with insulation to help the draft the bubble one is never a problem but the solid fuel one can stick on the collar the joys of boating

 

Peter

Quite so if your referring to me old bean, that's why I have no time for collar overlapping chimneys or expensive double skinned efforts.

[Mac of Cygnet]

I had a lot of goo regularly leaking out of the bottom of my single skinned chimney. When I fitted a coolie hat to it though, it stopped.

 

Guessed it somehow reflected heat back into chimney and so reduced the condensation that created the goo, unless anyone has a better suggestion.

 

However a Chinaman's hat overlaps the chimney and in cold wet weather can produce tarry condensate which drips on the roof or even down the side of the boat, depending on angle. Especially if burning wood. I only ever put my chimney hat on when the stove is NOT burning, to keep the rain out (it doesn't matter when the stove is burning).

[jelunga]

 

a goods stainless one should last indefinitly, whereas galvanised ones corrode away in a couple of years. Pretty sure a s/s one will be more economical in the long term. A double skinned one will also insulate the chimney, and get you a better draft.

What he said re updraft. Makes a big difference to our bubble stove efficiency too.

[bowten]

Get a twin wall chimney and pack rock wool between the inner and outer walls,this will stop condensation and tar running down.

[Grace and Favour]

Get a twin wall chimney and pack rock wool between the inner and outer walls,this will stop condensation and tar running down.

That's what we've done too....... and very pleased with the result

[Guest]

Thanks all ~ double skin chimney ordered from eBay.

 

£35 including a rain hat and a rather pricey p&p.

 

Managed to find a plain black one rather than one with silly chrome or brass bands.

 

May give it some additional paint before I use it.