20 year old stoves shouldn't be touched, they're usually polluted with asbestos.
The scrap mongers working on a legal base won't take them.

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Thanks, but at my age I'm not worried about asbestosis - something else'll get me first.

mike7
 
Thats the way be positive and live life, have a beer or 2, have a smoke as well, if thats the way you live, good on ye mate.

Well, if you're looking for advice on how to commit crimes(handling and dumping of illegal substances) then this a case for the moderator. Or the police.

Aaargh - they're on to me!

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An attempt to get the ball rolling...
The problem with the Rayburn was that it produced too much hot water and too little room/oven heat.
 
I removed the firebricks on the oven side of the firebox, and added brick elsewhere to within 80mm of the top. (For experimenting I used cement paving slabs and blue paviours rather than proper firebrick). Good result so far.
 
I also removed the grate and riddling stuff as not required for wood, so I can load longer logs. It helps.

Are you aware that these "bricks" are legally necessary? To insulate the steel/joints, to avoid you suffocating? To make the machine fire-proof, to protect it against a steam driven explosion? To make it -ahem- efficient?
 
These "bricks" are called "clinker" by the way....
And are you aware that with such a DIY construction you've lost the insurance cover?
"Greenbuilding" doesn't mean to put other lifes at risk by trying to save a few bobs. Be it the illegal dumping of asbestos or the call-out of the fire brigade or the unecessary stretching of the health system....
Do you know how much a (burned)skin transplant costs caused by an exposure to a steam explosion?
Sure fridihem will pour a can of oel over it....
 

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I also darn my own socks without making a risk assessment.
 
Happy New Year, everybody!

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To get more heat into the room from the Rayburn in winter, I've made a new firebox top door with fins inside and out. See photo.
 
Also there's now a shelf inside for firelighting halfway up the vertically stacked 45cm logs so I get a top-down burn.(This makes less smoke, esp. when lighting.)
 
Overall result with previous firebrick adjustments is enough hot water but not too much, an oven that gets to 150oC without caning it, a warmer kitchen, and hardly any visible smoke. I'm pleased.

@mike7:
Have you meassured the flue gas temperatures a.)at the outlet of the stove and b.) at the top of the chimney?
What readings did the thermometer give?

I measured the temperature at the flue restrictor during one burn. It varies a lot, obviously. Increased to a max of 255oC at the end of the hottest ie smoke-burning phase, and then with more restricted air supply reduced to something in the region of 120 - 130 C until refuelling. Chimney top is beyond my reach. Early part of the burn produced visible smoke and steam to atmosphere, smoke reducing quite early on, and then apparently just steam at hottest flue temp. Later on nothing visible other than heat turbulence. All very subjective, of course.

Hi Mike
Can I ask what you used to measure the waste gas temps please? I have a fault on a waste gas thermostat on my boiler and I would like to be able to see what sort of temps the flue gas reaches presumably it's hottest where it exits the boiler?
Cheers
julian

Thanks, mike7.
I was wondering about the condensation risk within the chimney, the risk that tar builds up.
Therefore the fluegas temperature at the top of the chimney must have a min.temperature.
Some people do not understand this until they have the chimney at fire. Or worse.
Tars and oils creating this combustable sediment will have a higher condensation temperature then water, well above 100 degrees Celsius.
This minimum temperature avoiding the condensation effect has to be met at all times. So making a stove/boiler more efficient might be a short sighted saving....
A new chimney and the fire brigade at the house will cost more then the fuel being saved.
There are special boilers called condensing boilers designed to work on this condensing modus.
They cost around 500 pounds when running on gas.(B&Q)
And then there are high efficiency boilers to work with fluegases of around 150-200 degrees.
But these need special chimney liners suitable for the pupose, the standard cold chimney consisting of soaking bricks and unglazed clay pipes is certainly not suitable for these low temperatures.
 
120-130 degrees Celsius 'warm' fluegases entering a standard chimney build originally for example for an open fire place is illegal. A high risk to all near to it.

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I used a multimeter with a thermocouple - probably from RS or CPC. I check it in boiing/iced water sometimes, and it is quite good in that range at least. I also have a couple of infra-red thermometers, but they seem a bit inaccurate- inclined to drift. Good for quick measurements of temperature difference, but maybe not for absolute values. Anyone recommend a good one?
From a cold start there is bound to be some condensation initially, so another good reason to run up to a high temp to dry that. Hot burning is what I wanted to minimise tar etc emissions. If nevertheless these pollutants escape the firebox unburnt, there's an argument for hoping they'll settle in the chimney rather than poisoning the atmosphere. Provided you sweep the chimney often enough!

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Once the fuel is reduced to charcoal, I see less reason to have a high temp exhaust.
 
So as to get a high firebox temp, I suppose you want to minimise the air supply, which means making the airflow in as turbulent as possible, also the burning gases themselves, to make best use of the oxygen available. For that reason I have reduced the pathway for the incoming air (where the ash tray was) so the air speed is high when it meets the fuel. I also have a steel plate leaning against the logs so that the burning gases are kept moving and mixing, in close contact with the fuel, rather than lazily drifting about above.
 
I can't say for sure if it makes any difference, but the theory seems right.

Mike7 wrote:
" ...Hot burning is what I wanted to minimise tar etc emissions. If nevertheless these polutants escape the firebox unburnt, there's an argument for hoping they'll settle in the chimney rather than poisoning the atmosphere. Provided you sweep the chimney often enough! .."
 
Get professional advice. Your DIY aproaches handling dangerous substances like carcinogenic asbestos and PACs is a criminal act. An offence against the law.
Bitumen-build up can't be swept away in the chimney.
Back to school,learn under supervision of an adult.

I'm coming to the conclusion that the Rayburn was designed for coal or coke, not wood. The firebox is rather small and it is difficult to get a good load of wood in,especially if the space is further restricted by the internal re-arrangements I've been trying. Also, I'm running low on fuel of suitable size.
 
So, my attention lately has been on the Yeoman, with efforts to concentrate and separate the combustion zone from the business of heat transfer to the room. I've found that offcuts of suspended ceiling tiles make a quite effective refractory lining, and they last much longer than I would have thought.
 
The more involved I get, the more it seems essential to have some means of measuring results with some degree of accuracy. One way to do it would be to fork out for the kind of flue gas analyser used by heating technicians to set up/service stoves, but they're quite expensive, and probably over-elaborate for my needs. Any ideas, anyone? As a minimum I need to know the oxygen percentage, and carbon monoxide level would be good too.

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