Sawdust Briquettes

[TeeDee]

Has anyone experience of these Sawdust Briquettes? I mean , if one can get the sawdust for free and if one is happy to expend ones labour do they actually burn and give off enough heat be worthwhile ? or just sit there and silently smoulder like an angst ridden emo child?

I have a timber yard close to me so its a possibility , and an empty greenhouse to dry them.

Or is it a well intentioned hang over from the Good Life days ?

 

[Nice65]

I didn’t like them much in a burner, they expand and break up, then fall out. First time I tried them I stuffed it full and closed the door expecting an evening of warmth. Instead I got a cracked fire tile inside as they expanded.

Like logs, it’ll depend on the timber as to how they burn, but emo teen is closer than most descriptions. They burn, well, like sawdust, and they do it quite quickly if you open the vents for some flames. I soon gave up with them and only grabbed a bag if we were out of logs.

Hand making them? I saw the machine that made mine and there’s no way of compressing them like that by hand, you’ll burn more energy than you get back.

 

[Watch-keeper]

I have used the commercially produced briquettes in my burners and was happy with the results.
The ones i used produced decent heat, lasted a decent amount of time and didn't cause me any problems.
When I use them, I establish a fire with wood then throw the briquettes on as required.
Like Nice65 said they do expand and break up, but it didn't cause me any problems as I was just throwing them on when needed.
As for making them I really have no experience with it so cant help, but if you have access to a ton of sawdust it sounds like its worth a try. I expect getting them to dry sufficiently will be key to getting a good burn.

 

[Toddy]

They're hard work to make, hard to dry properly, but they do use up free stuff. At some points the workshops produce over a ton of sawdust a week, it seemed a good idea.
Hmmmm was the best result.

When coal fires were ubiquitous, folks used to buy briquettes to eke out a slow overnight fire. They didn't burn particularly well, but they were cheap, they were a safe charcoal sort of burn. Made it easy to bring on a quick fire again in the morning, and in the days of back boilers meant that there was some heat in the water too.
Maybe these would be best thought of like that ?

Looks so simple, but the reality of the effort involved kind of killed any interest in making them. Bit like the paper logs too.

 

[TeeDee]

Yes an overnighter , " keeper in" may be the best use. Smouldering is a good thing in some circumstances , big screen Hollywood romances and saving a fire pan from a cold restart being the other.

As for the making of them I agree its a fair amount of work -more so the drying of them. The best option seems to be to ignore the commercially available units which seem to be flimsy and lack the adequate pressure and go straight to some jury rigged press using a jack or pressure of some sort - even leaving the log over night under pressure would yield impressive benefits but then the operation becomes a daily chore. Worth it if one makes a multi chambered loading pot I guess. One log press a night and leave under pressure for 6 hours.

 

[Toddy]

That's the kind of practical household economy that I can get behind
They'd dry out on top of an evening lit stove too I reckon. Just get a quiet system going and do it. Probably take a few days to dry thoroughly though.

I know the lads added wax and resins to the logs trying to speed things up, to make them 'more', but tbh, the enthusiam quickly died a quiet death, and everything they added just added to the pollution and tar in the lum.

 

[TLM]

Saw dust pellets seem to be used here but briquettes are rarely seen, they exist though so somebody is using them. I remember almost melting a sauna stove with them 60 years ago, so by volume they are more energetic than any normal wood, not tested any of the woods having dry density over 1 though.

 

[Toddy]

I hadn't realised that they could be hotter than normal logs....I know in the workshop they just shoved them into the big furnace as fuel....and that the briquettes that folks bought in my childhood did not burn hot, they were a slow burn fuel.

 

[Pattree]

I think the term “briquettes” covers a number of items. In my childhood something called a briquette was made of coal dust. My Irish relations used to buy peat briquettes. I hadn’t heard of wood dust ones until this thread. Might that account for temperature difference?

It’s going to be hard to dry wood dust down to 20% moisture. It’s so very absorbent. Just the ambient humidity is going to be a problem.

I’d like to think that there is a way of doing it without a furnace. Very best of luck.

 

[Nice65]

I hadn't realised that they could be hotter than normal logs....I know in the workshop they just shoved them into the big furnace as fuel....and that the briquettes that folks bought in my childhood did not burn hot, they were a slow burn fuel.

Pellets, like old Bri used to use in Robson Valley are fuel of choice for specialist burners. His did the whole house, water and heating but those pellets and burners have been tweaked for efficiency. There’s a big difference between those and the compressed sausages of wood chip.

In my experience they burn more like peat than wood unless the vents are wide open, in which case they burn really hot and are gone in no time.

 

[TLM]

It’s going to be hard to dry wood dust down to 20% moisture. It’s so very absorbent. Just the ambient humidity is going to be a problem.

That depends, here the moisture can be down to 14% very much depending on conditions, getting under 20% is not hard.

 

[Nice65]

That depends, here the moisture can be down to 14% very much depending on conditions, getting under 20% is not hard.

Not here. Leave a sack of them out for a season and you've got a sack of sawdust or very messy fuel.

 

[Toddy]

It's the middle of summer here, and I'm running dehumidifiers because above 67˚ moisture we grow mildew.....I don't want to put heat on to dry out the house, and I don't dry washing indoors.....but the UK is a temperate damp climate.
20% moisture would be woah!, don't think we've ever done 20% moisture.

 

[Pattree]

That’s what comes of living on a dripping wet muddy little island on the edge of the Atlantic. Finland has a distinct advantage. We don’t even get sharp frost any more in the Midlands. A good frost can drop humidity down to 13% by freezing the water out of the air (and stop the industrial process that I used to supervise).