Morso Squirrel - cracked back plate

[stuart]

In the process of cleaning up and refurbishing my morso stove, and just noticed the back plate has a hair line crack along the corner where the back curves around.

 

What are my options? Can this be welded/repaired?

 

Looks like a new back plate is around £120 - at least they are available I suppose, just didn't want to spend that sort of cash!

Edited January 27, 2013 by stuart

[RLWP]

I suspect that if you take it apart, other bits will also drop off

 

Richard

[Titus]

On my last boat I took the stove apart to recon it and had the back plate welded

[waterworks]

drill a small hole at the end of the crack to stop it spreading, then forget about it, it's not important.

[PaulJ]

drill a small hole at the end of the crack to stop it spreading, then forget about it, it's not important.

I think the BSS man might think differently though...

[Teadaemon]

I think the BSS man might think differently though...

 

This BSS man certainly does, as it's a failure of check 8.10.5 Are all solid fuel appliances free of unintended gaps?

 

Don't think this is an unimportant check because it's only advisory, that just means you're only likely to kill yourself, rather than endanger any other boaters.

 

More importantly, it means that combustion gases, potentially including carbon monoxide (present is solid fuel flue gases at about 100 times the concentration of LPG flue gases), can enter the interior of the boat. I would strongly advise that under no circumstances is this stove used while this crack is present.

 

Here's a link to a pdf copy of the leaflet I'd be giving you if I'd found the crack in the stove in the course of a BSS examination.

 

Edited to add:

 

As far as repair options go, what is the back plate made from? If it's steel then drilling the end of the crack and then welding is likely to be a fairly easy repair. If it's cast iron then it's more difficult, but still possible (though you may have to find a proper welder who knows what they're doing and has the kit to do it).

Edited January 27, 2013 by Teadaemon

[nicknorman]

 

More importantly, it means that combustion gases, potentially including carbon monoxide (present is solid fuel flue gases at about 100 times the concentration of LPG flue gases), can enter the interior of the boat. I would strongly advise that under no circumstances is this stove used while this crack is present.

 

 

That is of course the "party line". But is it logical? If you have a crack in the back, why would fumes leak out when the draw of the chimney is keeping the interior of the stove at slightly reduced pressure compared to the boat? In the front of the stove, you have a gap (the air vent) so why would fumes come out of a crack in the back, but not the hole in the front?

 

I wouldn't want a crack in the back in case it got worse and the back fell off and released burning stuff into the cabin. I just can't see the bit about the fumes though.

[Teadaemon]

That is of course the "party line". But is it logical? If you have a crack in the back, why would fumes leak out when the draw of the chimney is keeping the interior of the stove at slightly reduced pressure compared to the boat? In the front of the stove, you have a gap (the air vent) so why would fumes come out of a crack in the back, but not the hole in the front?

 

I wouldn't want a crack in the back in case it got worse and the back fell off and released burning stuff into the cabin. I just can't see the bit about the fumes though.

 

CO will continue to be released from embers, ashes, and part-burned coals even after they've cooled down to room temperature. Getting the flue to draw effectively requires the internal temperature of the stove to be somewhat above this (I don't know exactly how much, I don't design stoves for a living). Therefore, it is highly likely that at some points during the operation of the stove, flue gases will not be being drawn effectively up the chimney, and will be able to leak through any crack in the stove. Also, if there is a crack then it's only going to get bigger, and it may do so suddenly and without warning.

 

Don't mess around with CO, it's really not worth the risk.

[MoominPapa]

CO will continue to be released from embers, ashes, and part-burned coals even after they've cooled down to room temperature.

How does that work? It can't be CO from newly-oxidised carbon, otherwise coal left at room temperature would gradually disappear as is emitted CO. I suppose CO produced during combustion could be adsorbed by the carbon and/or ashes and released later, but that's not an effect I've ever heard of.

 

MP.

[Teadaemon]

How does that work? It can't be CO from newly-oxidised carbon, otherwise coal left at room temperature would gradually disappear as is emitted CO. I suppose CO produced during combustion could be adsorbed by the carbon and/or ashes and released later, but that's not an effect I've ever heard of.

 

MP.

 

In the case of cooling embers I suspect that both mechanisms are happening to one degree or another.

 

I know for a fact that when a friend of mine had a small fire on his wooden cruiser last September (caused by an electrical problem), there was enough CO being produced by a foot square patch of charred bulkhead to set off a CO detector within minutes of it arriving on board 12 hours after the fire, despite the boat being aired thoroughly to try to remove any smoke.

 

It really doesn't take much CO to be a serious threat to health, as it builds up over time. To get a bit technical CO bonds irreversibly to heamoglobin, reducing the capacity of the blood to carry oxygen until the affected red blood cells have been replaced by the body. As it takes about 3 months for the average human to completely renew their red blood cells, even very low concentrations can be dangerous if someone is exposed for a long time, as might well be the case if they live on a boat with a faulty solid fuel stove.

[nicknorman]

So why isn't CO released from the hole in the front (air vent). Sorry, it just doesn't seem logical to say it will come out of the back but not the front.

 

How does that work?

It doesn't, not once the embers have cooled.

[Radiomariner]

How does that work? It can't be CO from newly-oxidised carbon, otherwise coal left at room temperature would gradually disappear as is emitted CO. I suppose CO produced during combustion could be adsorbed by the carbon and/or ashes and released later, but that's not an effect I've ever heard of.

 

MP.

 

I'm not too sure of the science behind it either MP. But there have been incidents where warm ashes left in a bucket in the cabin ovenrnight have resulted in CO poisoning.

I guess as long as the embers are still hot they are still burning but not efficiently enough to maintain their heat, Inefficient burning results in CO.

Edited January 27, 2013 by Radiomariner

[Teadaemon]

So why isn't CO released from the hole in the front (air vent). Sorry, it just doesn't seem logical to say it will come out of the back but not the front.

 

 

It doesn't, not once the embers have cooled.

 

I never said that it wouldn't come out of the air vent too, in fact I strongly suspect that it would.

 

However, the air vent is a hole in the stove that is known about during the design process, and it's effects can be accounted for during that process. A crack is not an intended part of the design, and it's effects are not predictable by the designer.

 

If embers have cooled to ambient temperatures then CO will no longer be generated by the oxidation of carbon, but it would be extremely foolish to assume that all of the CO generated by incomplete combustion enters the atmosphere immediately. Some will be trapped within the embers, coal or ash and be released over time. I know this happens with burned wood, as I've seen the evidence myself, and it would be reasonable to expect that it happens with other solid, carbon-based fuels to one degree or another.

 

Look, we could go around in circles for ages, but at the end of the day do you really want to advise somebody that it's ok to carry on using a stove that might (even if it's a fairly small chance) kill or seriously injure them? I certainly don't.

[TNC]

In the process of cleaning up and refurbishing my morso stove, and just noticed the back plate has a hair line crack along the corner where the back curves around.

 

What are my options? Can this be welded/repaired?

 

Looks like a new back plate is around £120 - at least they are available I suppose, just didn't want to spend that sort of cash!

 

I know it does not help you, but there are 4 scrap Morso Squirrels at Riversdale....the problem this in in Ireland and I wont be going over again untill Easter!

I am pretty sure one has a good back plate. I dont think Graham can be ar$ed to split them down for spares, so I will look into stripping, shotblasting the bits and getting them back to Blighty.

[MoominPapa]

I'm not too sure of the science behind it either MP. But there have been incidents where warm ashes left in a bucket in the cabin ovenrnight have resulted in CO poisoning.

I guess as long as the embers are still hot they are still burning but not efficiently enough to maintain their heat, Inefficient burning results in CO.

I think this is quite possible: ashes fron the fire still contain some unburned fuel which is kept hot for a long time because the surrounding ash is good thermal insulator and continues to burn slowly because the surrounding ash limits the air supply. Hence CO production. That's not the same as CO production from "part burned coals that have reduced to room temperature" which is what Taedaemon asserted and what I'm querying.

 

Wether the heat production of an ash/coal residue in a stove reduces far enough to stop chimney daft before the CO production becomes negligable is the important question for CO poisoning. Here, the existance if engineered hole in stove (like the air control) suggest that it's not a problem in practise.

 

MP.

[Teadaemon]

I think this is quite possible: ashes fron the fire still contain some unburned fuel which is kept hot for a long time because the surrounding ash is good thermal insulator and continues to burn slowly because the surrounding ash limits the air supply. Hence CO production. That's not the same as CO production from "part burned coals that have reduced to room temperature" which is what Taedaemon asserted and what I'm querying.

 

Wether the heat production of an ash/coal residue in a stove reduces far enough to stop chimney daft before the CO production becomes negligable is the important question for CO poisoning. Here, the existance if engineered hole in stove (like the air control) suggest that it's not a problem in practise.

 

MP.

 

My take on it, backed up by observational evidence (admittedly only of one case) is that CO produced while solid fuel is burning can remain trapped inside embers and part-burned coals, and continue to diffuse out of them even after they have returned to room temperature. I can't quantify how much CO is trapped, or how quickly it diffuses into the atmosphere (I suspect both will vary quite widely), but I know it can happen.

 

On the question of how hot a flue needs to be to work effectively, whilst I don't have any data for solid fuel stoves, I did read a gas stove manual last night that recommended running the stove on hot for at least 10 minutes after starting in order to ensure that the flue was drawing properly. this would suggest to me that it needs to be significantly above the ambient temperature.

[nicknorman]

Look, we could go around in circles for ages, but at the end of the day do you really want to advise somebody that it's ok to carry on using a stove that might (even if it's a fairly small chance) kill or seriously injure them? I certainly don't.

 

I never said that I advised him to keep using the stove - as we both mentioned a crack can suddenly get worse to the extent the back falls off. I just wanted to examine what I consider to be the myth that fumes would escape from a small crack in the back, and not from the vent in the front. You may think I am being picky, but, whilst you are perhaps happy just to follow the rules, I want to understand what is behind the rules.

 

On the subject of CO we have probably all found that when we rake out an apparently cold stove that has been burning coal, some glowing embers can be uncovered that could produce (a fairly small amount of) CO. However, for the chimney to draw, the interior of the stove doesn't have to be above room temperature, it just has to be above outside air temperature. So lingering warmth in the room will result in convection (draw) up the chimney, albeit to a very small extent.

Edited January 28, 2013 by nicknorman

[wonderdust]

In the process of cleaning up and refurbishing my morso stove, and just noticed the back plate has a hair line crack along the corner where the back curves around.

 

What are my options? Can this be welded/repaired?

 

Looks like a new back plate is around £120 - at least they are available I suppose, just didn't want to spend that sort of cash!

 

Don't want to get into the fume argument, i have used JB Weld on a small 1" crack on my stove, i drilled a hole as stated in previous answer and then filled with JB weld all seems ok and has not opened up in the last 18 mnths

[bizzard]

Might be best to ask a Red Indian, that sat around an open fire of sticks in a Wigwam.

Eskimos did it too in their Igloos, with the added danger of the fire suddenly thawing out their home.

Edited January 28, 2013 by bizzard

[nicknorman]

Might be best to ask a Red Indian, that sat around an open fire of sticks in a Wigwam.

Eskimos did it too in their Igloos, with the added danger of the fire suddenly thawing out their home.

 

And of course the good folk of Scotland who live in "black houses" with an open fire in the middle and hole in the roof. But of course we are tough up here and don't get all girly about a bit of CO. It saves on the sleeping pills.

[stuart]

I know it does not help you, but there are 4 scrap Morso Squirrels at Riversdale....the problem this in in Ireland and I wont be going over again untill Easter!

I am pretty sure one has a good back plate. I dont think Graham can be ar$ed to split them down for spares, so I will look into stripping, shotblasting the bits and getting them back to Blighty.

 

Let me know how you get on with those, might take me that long to refurb the stove!

 

 

The stove is currently in bits all stripped down to individual panels, so far I've only found a crack on the back plate - its the back boiler model by the way, with 2 holes in it.

 

 

I think I've had a long term issue with water in the bottom of the stove and this has corroded one corner of the stove as this seems to have all the issues and the most rust.

 

 

The crack is quite visible (see day light through it!), so doubt any repair would work - is it possible to get these welded?

[bizzard]

A stove when not alight during the summer needs to be kept ventilated inside to prevent rusting by the use of a Coolie hat to stop rain from entering and by leaving the ash pan door adjar to keep a good ventilating draught through it. I wouldn't under any circumstances cap off the chimney outlet with one of those soppy caps or old paint tins.

[nicknorman]

A stove when not alight during the summer needs to be kept ventilated inside to prevent rusting by the use of a Coolie hat to stop rain from entering and by leaving the ash pan door adjar to keep a good ventilating draught through it. I wouldn't under any circumstances cap off the chimney outlet with one of those soppy caps or old paint tins.

All very well if you don't cruise on narrow canals! Chimney + coolie hat = bridge banging! We cap the chimney in summer but leave the air vents open - seems to prevent any issues. Plus non-vertical rain gets past a coolie hat!

[bizzard]

All very well if you don't cruise on narrow canals! Chimney + coolie hat = bridge banging! We cap the chimney in summer but leave the air vents open - seems to prevent any issues. Plus non-vertical rain gets past a coolie hat!

Easy to make an ultra low coolie hat by cutting out a disc of sheet steel, copper or whatever, slit it to the centre, draw it round to form a mild cone shape, drill and pop rivet it. Legs I've found are best made from three lengths of either 10mm or 15mm copper pipe flattened out, bent to shape drill and pop riveted to the hat. Copper snap head rivets last longer though, as this hat probably won't be used when the stoves alight will last and probably see you out.

[TNC]

Let me know how you get on with those, might take me that long to refurb the stove!

 

 

The stove is currently in bits all stripped down to individual panels, so far I've only found a crack on the back plate - its the back boiler model by the way, with 2 holes in it.

 

 

I think I've had a long term issue with water in the bottom of the stove and this has corroded one corner of the stove as this seems to have all the issues and the most rust.

 

 

The crack is quite visible (see day light through it!), so doubt any repair would work - is it possible to get these welded?

 

The Riversdale ones have suffered from rust/damp, so there won't be many good bits...well it is Ireland!

One reason I opted for an all welded steel carcass Villager Puffin (I also needed a stove a bit narrower and won't be buring wood - cheap turf brickettes!)

My 'ol man* could have welded it....he gas welded up our old house stove and I still have 4 ally boxes, with the seems beautifully gas welded!

AFAIK is is a question of skill and the right flux. AFAIK the best practise is to do some weld stitches across, then fill in between....that is certainly the way cracked cast stuff has been repaired in the railway preservation movement.

 

'ol man*

He was a proper panel beater at James Young's