Chimney Collar

[tjh82]

Hello

We're fitting a new stove to our dutch barge.

The new flue is going to be 150mm diameter - does anyone know where i could source a cast iron collar with an internal diameter of this size please?

Everything seems to be 127mm

Thanks a lot!

Tom

[CompairHolman]

The collars you buy from chandlers are only cast iron because of tradition, there is no reason why a fabricated steel collar will not do the same job, so if you're stuck then any local welder / fabricator can make you one to suit. I have made them myself from plate and tube and its an easy ( low cost ) job. 

 

 

[David Mack]

Why are you using 150 flue? Usual practice on stoves with a 150mm/6 in flue outlet is to reduce to 5" and then fit a 5" flue.

If you use a larger flue and collar I think you will struggle to find a chimney to fit.

[bizzard]

The hole in the collar needs to be wider than the flue pipes o/d. You need about a 1/2'' clearace all round to accomodate fure proof rope and goo. The flue pipe needs to move up and down in it as it heats and cools.  Also if the the pipe is close or a tight fit metal to metal contact with the collar the paint on the roof surrounding the collai is likely to scorch, it will also heat up the inner roof too much internally between ceiling and panelling.

[Jen-in-Wellies]

^^^^^This. There needs to be a gap between the flue and collar, filled with fibreglass rope and high temperature silicone sealant. The flue expands in length when  hot and the gap and compliant filler accommodate this expansion. Without it the top of the stove can crack from the stress. Also needed to reduce the heat transfer to the ceiling.

Going for a bigger flue than normal means that the collar and chimney will have to be custom made.

 

Jen

[tjh82]

Thanks for your responses.

We're hoping to install a new stove that comes with a 'balanced flue' set up to improve draw as we're surrounded by high flats.

The special flue system they make is 150mm so i guess we'll have to get a collar specially made (with sufficient space to add rope and sealant.

Thanks again 

[Nightwatch]

May I intervene? I am anticipating replacement of our cast iron flue, oringinal to our Squirrel fire. (It keeps furring up and nigh on blocking. ) I am going to remove and have a good go at removing residues of some sticky, some solid as concrete material that has caused this issue. Cheap coal I guess and burning at low temperatures.

 

Anyway, measured diameter of existing flue and the nearest I can get is a scrinchal (is that a correctly spelt word?) over 4". 

As I'm near Midland Chandlers, have looked on their webby thingy and they sell Morso flues at £200+ and steel flues for £55. Now, cost is important, but so is quality and prolonged life, don't want to be doing this anytime soon. The steel flue is 4.5". 

 

Question. How many sizes do flues come in? Is there a 4" one? Will a 4.5" flue fit my Squirrel? Are the Morso flues worth the money (investment)? Midland site does not state diameter of the Morso flue.

 

Now going in search of other suppliers and their available flues.

 

(All this and I've had my flu(e) injection)

 

[Jen-in-Wellies]

 

11 minutes ago, Nightwatch said:

Will a 4.5" flue fit my Squirrel? Are the Morso flues worth the money (investment)? Midland site does not state diameter of the Morso flue.

I have a Midland SwinChandlers 4.5" flue on my Squirrel stove. This is number three in twelve years of use in a live aboard boat, so around five years use per flue before the tin worm eats through them. No idea if the Morso one is better in terms of life, or draw, as I've not used one.

 

If there is an offset between the stove outlet and the collar and you want to use a straight flue, with no welded angles, then you may need to use a 4", or smaller pipe to fit through at an angle.

 

Jen

Edited November 11, 2019 by Jen-in-Wellies

[David Mack]

48 minutes ago, tjh82 said:

Thanks for your responses.

We're hoping to install a new stove that comes with a 'balanced flue' set up to improve draw as we're surrounded by high flats.

The special flue system they make is 150mm so i guess we'll have to get a collar specially made (with sufficient space to add rope and sealant.

Thanks again 

Is this a solid fuel stove with balanced flue? Please can you provide details as I have not come across one before.

Any balanced flue appliance needs the proper flue terminal to provide access for air in and flue gases out, usually by having concentric tubes (flue gases up the middle, air down the oute annulus), so you can't use a standard chimney and collar. I would expect the stove manufacturer to suply a suitable roof fitting.

[Jen-in-Wellies]

3 minutes ago, David Mack said:

Is this a solid fuel stove with balanced flue? Please can you provide details as I have not come across one before.

Any balanced flue appliance needs the proper flue terminal to provide access for air in and flue gases out, usually by having concentric tubes (flue gases up the middle, air down the oute annulus), so you can't use a standard chimney and collar. I would expect the stove manufacturer to suply a suitable roof fitting.

Also, it may depend on having a normal house size height to work properly. Twenty, or thirty feet high, not the six or so feet in a typical boat installation. No idea if this is the case, but more details would be good.

Jen

Edited November 11, 2019 by Jen-in-Wellies

[rusty69]

7 minutes ago, Nightwatch said:

Question. How many sizes do flues come in? Is there a 4" one? Will a 4.5" flue fit my Squirrel? Are the Morso flues worth the money (investment)? Midland site does not state diameter of the Morso flue.

I think one of our squirrels has a 4.5" od pipe, the other is a 4" od mild steel pipe from a steel pipe supplier. 

 

Either size will fit depending on the size of your roof collar, assuming it is a straight pipe, and not installed at a silly angle. I think morso recommend a 4.5" pipe, and certainly the bigger pipe will function better. 

 

Midland chandler's used to sell a reducing collar. 

 

I clean our flue with a 6ft scaffold pole with a bolt through it. Clears the clag nicely. I have heard of people using a length of chain too. 

[bizzard]

4 minutes ago, Nightwatch said:

May I intervene? I am anticipating replacement of our cast iron flue, oringinal to our Squirrel fire. (It keeps furring up and nigh on blocking. ) I am going to remove and have a good go at removing residues of some sticky, some solid as concrete material that has caused this issue. Cheap coal I guess and burning at low temperatures.

 

Anyway, measured diameter of existing flue and the nearest I can get is a scrinchal (is that a correctly spelt word?) over 4". 

As I'm near Midland Chandlers, have looked on their webby thingy and they sell Morso flues at £200+ and steel flues for £55. Now, cost is important, but so is quality and prolonged life, don't want to be doing this anytime soon. The steel flue is 4.5". 

 

Question. How many sizes do flues come in? Is there a 4" one? Will a 4.5" flue fit my Squirrel? Are the Morso flues worth the money (investment)? Midland site does not state diameter of the Morso flue.

 

Now going in search of other suppliers and their available flues.

 

(All this and I've had my flu(e) injection)

 

The ordinary mild steel fue pipes usually have 1/4'' 6mm thick walls so would be fine.  I reckon you've been bunging wet or damp fuel on the fire. Most of The smokeless nuts have a cement like binder and some like Excel are petro cokes. When damp or wet and burnt just ticking over the moisture and cement binder in the smoke bond together and go solid in the flue pipe and block it up. Does you Morso have a back boiler? if not it is imperative that the half moon throat plate is removed. Always make sure the fuel, smokeless or wood is dry before bunging it on.

[tree monkey]

14 minutes ago, Nightwatch said:

May I intervene? I am anticipating replacement of our cast iron flue, oringinal to our Squirrel fire. (It keeps furring up and nigh on blocking. ) I am going to remove and have a good go at removing residues of some sticky, some solid as concrete material that has caused this issue. Cheap coal I guess and burning at low temperatures.

 

Anyway, measured diameter of existing flue and the nearest I can get is a scrinchal (is that a correctly spelt word?) over 4". 

As I'm near Midland Chandlers, have looked on their webby thingy and they sell Morso flues at £200+ and steel flues for £55. Now, cost is important, but so is quality and prolonged life, don't want to be doing this anytime soon. The steel flue is 4.5". 

 

Question. How many sizes do flues come in? Is there a 4" one? Will a 4.5" flue fit my Squirrel? Are the Morso flues worth the money (investment)? Midland site does not state diameter of the Morso flue.

 

Now going in search of other suppliers and their available flues.

 

(All this and I've had my flu(e) injection)

 

Maybe consider a stainless flue, I had one made by the little chimney company a boat based chap who did a fine job.

Hopefully it will last for years.

[BEngo]

Most boat flues are fabricated from steel pipe. 4.5 in pipe comes in acouple of wall thicknesses and is available from a steel stockholder, but will probably be a 6m length.  Mine will cut it into shorter pieces for not much money.  A whole length is cheaper than a part piece from MC.

 

N

[Nightwatch]

Thanks for all the comments from my intervention to this thread. I'm 99% sure the flue we have is cast iron. Certainly be suprised if its steel. Having said that, I'd like to keep this one if I can dislodge the 'stuff' from within. Was thinking of a scaffold pole cut at an angle to form a sharp ish point. But the pole with a bolt through it sounds a good idea. Without committing theft! where can I get a scaffold pole from? How big a drink would I offer an abligeing scaffolder chappie? 

[bizzard]

30 minutes ago, Nightwatch said:

Thanks for all the comments from my intervention to this thread. I'm 99% sure the flue we have is cast iron. Certainly be suprised if its steel. Having said that, I'd like to keep this one if I can dislodge the 'stuff' from within. Was thinking of a scaffold pole cut at an angle to form a sharp ish point. But the pole with a bolt through it sounds a good idea. Without committing theft! where can I get a scaffold pole from? How big a drink would I offer an abligeing scaffolder chappie? 

Cast iron drain pipes were fairly popular. I had this happen to my flue pipe last January and also on another boat both blocked up completely with like solid cement. I got a length of steel 1/2'' water pipe  beat one end flat with a club hammer, bent it a shade and poked it down from the top. I had to turn it with a pair of 2' Stilsons before it broke through, like an auger it then all broke up and fell onto the grate, I then ran it up and down the flue pipe a few times, job done.  If your pipe is straight fine but if its has a dogleg bend, no good.

     My cousin Colin was a Teddy Boy and pulled a cast iron drain pipe up his leg to get an idea of what drainpipe trousers would look like.

Edited November 11, 2019 by bizzard

[Nightwatch]

8 minutes ago, bizzard said:

Cast iron drain pipes were fairly popular. I had this happen to my flue pipe last January and also on another boat both blocked up completely with like solid cement. I got a length of steel 1/2'' water pipe  beat one end flat with a club hammer, bent it a shade and poked it down from the top. I had to turn it with a pair of 2' Stilsons before it broke through, like an auger it then all broke up and fell onto the grate, I then ran it up and down the flue pipe a few times, job done.  If your pipe is straight fine but if its has a dogleg bend, no good.

Thanks for that. It's straight. 

[bizzard]

1 minute ago, Nightwatch said:

Thanks for that. It's straight. 

My cousin Colin was a Teddy Boy. When he first thought of becoming one he found an old cast iron drain pipe and pulled it up a leg to see in the mirror what drainpipe trousers would look like, he used up a whole bottle of iodine on all the bloody grazes.

[bizzard]

If the pipe is cast iron don't go banging at it with a hammer, cast iron is trecherous stuff and can suddenly crack like a carrot.

[Nightwatch]

I know. Very brittle.

[rusty69]

1 hour ago, bizzard said:

If the pipe is cast iron don't go banging at it with a hammer, cast iron is trecherous stuff and can suddenly crack like a carrot.

Well, that would be an easy method to remove it from the boat. Wrap it in clingfilm, and give it a whack.

Edited November 11, 2019 by rusty69

[rusty69]

2 hours ago, Nightwatch said:

Thanks for all the comments from my intervention to this thread. I'm 99% sure the flue we have is cast iron. Certainly be suprised if its steel. Having said that, I'd like to keep this one if I can dislodge the 'stuff' from within. Was thinking of a scaffold pole cut at an angle to form a sharp ish point. But the pole with a bolt through it sounds a good idea. Without committing theft! where can I get a scaffold pole from? How big a drink would I offer an abligeing scaffolder chappie? 

Now, that sounds like a worthy modification. I may have to get my angle grinder out. Careful not to drop the thing on the back boiler though.....could be messy.

Edited November 11, 2019 by rusty69

[Nightwatch]

Bog standard unit. No back boiler. 

[rusty69]

1 minute ago, Nightwatch said:

Bog standard unit. No back boiler. 

I guess you have checked the obvious....crap on the baffle plate?

[Nightwatch]

Just now, rusty69 said:

I guess you have checked the obvious....crap on the baffle plate?

Oh yes! Cleared before first flash up.  And I can get an angled poker thing we have on the top of it from the front. There's little bits but not enough to make a difference.

 

id like to remove, clear and refit, so cling film and a hammer may prevent such an outcome.