More woodburner questions

[Grahamshed]

Still debating about the woodburner but Ii am now wondering about burning stuff like MDF and chiboard and especially the sawdust from them. Anyone with experience ? Is it a problem ?

 

[dickm]

Officially, burning MDF or any product containing the sorts of resins used in its construction on a domestic stove, is frowned upon. However, most of us with wood stoves and living out in the wilds probably chuck the odd piece (and worse things!) on them without problems.
But probably not a good idea to burn a lot of it, especially anywhere near other houses.

 

[houtslager]

burn it all the time, just means the chimney needs sweeping 3 or 4 times a year.

hth

K

 

[jkljosh]

I agree with both the postings above. Your flue will need sweeping more frequently if you burn "man mades" and if you burn a lot your neighbours might not take kindly to their combustion products. I can't comment specifically on MDF sawdust as it's always mixed up with plenty of real wood dust in the extractor bag. I find burning sawdust a very effective way of heating the workshop - certainly less "stoking" than when burning logs/off cuts. I've a Greenheart stove from Workshopstoves and found their advice on installation, and how to burn sawdust invaluable. They've also expanded their range of stove styles since I bought 4 years ago. If you've not found their site, I'd whole heartedly recommend you check them out.

John

 

[Jacob]

I burn mdf, chipboard, no prob. They burn really well like phurnacite. And loadsa softwood including painted stuff. Any old rubbish, cardboard, some plastic, etc. Phurnacite when we run out. No probs with the flue either. It sees to be self cleaning, every now and then there's a tinkle of falling clinker, especially if the fire hasn't been on for some time. Checked this by having it swept once properly but there wasn't much to bring down.
Sawdust will burn from the top. You can't put it on a hot fire or it will blow back. Instead you let it burn down , then fill it up and light it at the top. All depends on the stove design of course.
It's a Dowling 'firebug', below. welded sheet steel, no fire bricks, for a long life. Has needed no maintenance in eight years of intensive use. Has been seen to glow red hot in the dark. Avoid cast iron and anything with firebricks.

If we get that far with the building conversion we will have another Dowling, the 'Sumo' -

 

[custard]

Sawdust will burn from the top. You can't put it on a hot fire or it will blow back. Instead you let it burn down , then fill it up and light it at the top.

What's "blow back"?

I've specified a woodburner for my new workshop that's being built now. I don't know if I've done the right thing, my previous workshop was central heated. On the plus side for the woodburner is cost saving and homely appeal. On the potential negative side is fire hazard, added dust and dirt, and general faff keeping it lit!

 

[heimlaga]

A blow back is when you throw sawdust onto a fire and it almost explodes in the air above the fire.

I agree. Burning saw dust is not a good idea unless you have either a lot of time or proper equipment. Chipboard should not be burned and MDF is questionable but I confess that at times the odd piece of it goes into the boiler. Most other forms of wood are all right.

 

[Jacob]

A blow back is when you throw sawdust onto a fire and it almost explodes in the air above the fire.

Or if you choke the fire with sawdust it smoulders away for some time then suddenly goes woomf.

... Chipboard should not be burned and MDF is questionable ....

Why not? In burns really well. I burn tons of both.

 

[newt]

A blow back is when you throw sawdust onto a fire and it almost explodes in the air above the fire.

Or if you choke the fire with sawdust it smoulders away for some time then suddenly goes woomf.

... Chipboard should not be burned and MDF is questionable ....

Why not? In burns really well. I burn tons of both.

Jacob, you may have missed one of the points, of course it burns well tons in your case, but what about the impact of the products of combustion on other folk, thought you were the caring type.

 

[Jelly]

... Chipboard should not be burned and MDF is questionable ....

Why not? In burns really well. I burn tons of both.

I presume due to the fumes from burning the adhesive matrix... However, if burned by adding to a fire that's already hot and drawing strongly; it ought be fine as the fumes will then combust/decompose themselves...

 

[Jacob]

A blow back is when you throw sawdust onto a fire and it almost explodes in the air above the fire.

Or if you choke the fire with sawdust it smoulders away for some time then suddenly goes woomf.

... Chipboard should not be burned and MDF is questionable ....

Why not? In burns really well. I burn tons of both.

Jacob, you may have missed one of the points, of course it burns well tons in your case, but what about the impact of the products of combustion on other folk, thought you were the caring type.

If it's toxic it might just as well go up my chimney as lie around being toxic as landfill.
I imagine the combustion breaks it all down pretty well anyway, as Jelly says above. It doesn't smell particularly and it burns cleanly. No reason to think it's any worse than other materials - coal contains all sorts of nasty stuff.
Plastic faced stuff is different though and you'd smell it in the neighbourhood.

 

[katellwood]

I would ask how waste disposal companies and Local Authorities get rid of Chipboard and MDF. as most LA's now incinerate most of their waste surely it just goes straight in the fire, or am I wrong

 

[Jelly]

I would ask how waste disposal companies and Local Authorities get rid of Chipboard and MDF. as most LA's now incinerate most of their waste surely it just goes straight in the fire, or am I wrong

Waste incinerators have to ensure that the flue gasses all reach at least 1500* degrees C, often by passing the flue gasses through a secondary burner unit. This reduces the amount of unsavoury combustion products released to acceptable levels; even so various scrubber units are often used to further reduce emmisions.

Realisticaly, its ensuring adequate draft that will make the biggest impact when burning products containing polymers... Ideally, there should be no soot, fine particulate smoke or vapours visible when burning, though the same goes for most things simply to reduce carbon monoxide risk.

*or maybe 1200, that region of temps certainly.

 

[Grahamshed]

Thanks guys. I have quite a lot of old chipboard/conti which I am using up as draw carcasses in the workshop. They are producing lots of offcuts I was intending to burn but once it is gone there is not likely to be any more.
I will be ordering my woodburner today but have to say I was horrified at how much extra the flues add to the price. I am going to have to spend a lot of cold weather time in there to justify the cost.

 

[Sheffield Tony]

I burn mdf, chipboard, no prob. They burn really well like phurnacite. And loadsa softwood including painted stuff. Any old rubbish, cardboard, some plastic, etc.

I'm glad I don't live downwind of your shop. Burning plastic is not a great idea; burning chlorinated plastic like PVC with paper/wood is an especially bad idea unless the flue gasses are kept hot enough (and a normal woodstove is not) to prevent the release of dioxins.

 

[Jacob]

I burn mdf, chipboard, no prob. They burn really well like phurnacite. And loadsa softwood including painted stuff. Any old rubbish, cardboard, some plastic, etc.

I'm glad I don't live downwind of your shop. Burning plastic is not a great idea; burning chlorinated plastic like PVC with paper/wood is an especially bad idea unless the flue gasses are kept hot enough (and a normal woodstove is not) to prevent the release of dioxins.

I don't burn plastic from choice but the occasional few bits get thrown in, tbh.
I still see no evidence that burning mdf or chipboard is a problem. But if it is so toxic and difficult to dispose of then people should consider not using it. They are the ones responsible for this toxic waste.
I don't use it myself, except when it's free and recycled. I haven't bought any new for many years.
From an environmental point of view generating heat from waste is a good thing as it reduces the use of fossil fuels, especially wood waste as this is carbon neutral