Burning Sawdust

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Burning Sawdust

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nasher1

Joined: 07 Oct 2013
Posts: 9
Location: SSE of Lincoln

Posted: Tue Oct 08, 13 3:58 pm Post subject: Burning Sawdust

I read a post about burning sawdust, I have experimented with this and found putting sawdust and shavings into a plastic sandwich bag, with a small amount of used veg oil, sealed with a tape machine works well. Recipe four good hand full’s of dust, an egg cup full of veg oil, one more hand full of dust on top of the veg oil, seal bag put on fire, easy with a good heat output.

I also spent a while looking into the possibility of making saw dust briquettes without wetting it, I saw that you need pressure and heat, with very little information to make a machine for domestic use. I have used a electric hydraulic log splitter (six ton), some steel box section, grease bucket as a hopper and three plastic injection heater bands (total 750 watts) The briquettes hold together well and burn very well. This home made lash up produces 5kg an hour.
Thank you for reading my first post.

Last edited by nasher1 on Tue Oct 08, 13 6:04 pm; edited 1 time in total

Tavascarow

Joined: 06 Aug 2006
Posts: 8407
Location: South Cornwall

Posted: Tue Oct 08, 13 4:40 pm Post subject:
Welcome from Cornwall. Like the idea of the briquettes, not sure we should be burning plastic bags though.

john of wessex

Joined: 18 Jun 2007
Posts: 2130

Posted: Tue Oct 08, 13 4:58 pm Post subject:
I've found that putting the sweepings from the wood shed into a paper bag works fine - sometimes even to well

nasher1

Joined: 07 Oct 2013
Posts: 9
Location: SSE of Lincoln

Posted: Tue Oct 08, 13 7:55 pm Post subject:
Thank you for the comments so far. The burning of plastic bags is not ideal in any quantity other alternatives should be found.

mousjoos

Joined: 05 Jun 2006
Posts: 1986
Location: VERY Sunny SW France

Posted: Wed Oct 09, 13 5:04 am Post subject:
Sounds a good idea but care should be taken if adding dust /shavings to a closed woodburner or stove

Mistress Rose

Joined: 21 Jul 2011
Posts: 15575

Posted: Wed Oct 09, 13 9:09 am Post subject:
The main problem with making briquettes on a domestic scale is getting the pressure needed to make the oils/resins flow. Your idea sounds good with the log splitter. Perhaps we ought to try something like that as we get lots of sawdust which contains bark, so no good for smoking food. Is yours hard or soft wood?

nasher1

Joined: 07 Oct 2013
Posts: 9
Location: SSE of Lincoln

Posted: Wed Oct 09, 13 5:05 pm Post subject:

Hello, Thanks for your question, yes pressure is the important bit but what I lack with the pressure from the log splitter, I make up with the band heaters. The box section I have used is 35mm square, as for the sawdust, I use whatever the joiner shop gives me it’s mostly a mix of fine, course dust with shavings and a mix of both soft and hard woods. (more soft wood than hard wood) If you take a look at this Guy’s home made machine https://woodgears.ca/reader/alois/press.html
Mine looks like a bit that has dropped off this one in comparison but sawdust goes in briquettes come out. I hope this helps.

Mistress Rose

Joined: 21 Jul 2011
Posts: 15575

Posted: Thu Oct 10, 13 7:21 am Post subject:
Thanks for that link. We get a lot of hardwood sawdust, and it would be useful to be able to do something with it. I know that briquette makers work best with a combination of heat and pressure; heat being more useful with softwood where there are resins present I think.

Mistress Rose

Joined: 21 Jul 2011
Posts: 15575

Posted: Sun Oct 13, 13 3:02 pm Post subject:
Could you give us some pictures of your set up as you say it is less complicated please?

gz

Joined: 23 Jan 2009
Posts: 8600
Location: Ayrshire, Scotland

Posted: Thu Jul 17, 14 4:37 pm Post subject:
Any more on this as we've been given three large bags of sawdust/small chippings?

Bodrighy

Joined: 15 Aug 2008
Posts: 2157
Location: Near Devizes

Posted: Thu Jul 17, 14 9:42 pm Post subject:
Be aware that not used right sawdust can be explosive. It does make brilliant pathways though as it inhibits weeds due to clotting up when wet and rots down so is very environmentally friendly. Also composts as well in small doses mixed with other stuff. Pete

gz

Joined: 23 Jan 2009
Posts: 8600
Location: Ayrshire, Scotland

Posted: Thu Jul 17, 14 9:54 pm Post subject:
Thanks Pete. Would be nice to press it back into logs, but I suppose that is only really a larger scale commercial proposition

dpack

Joined: 02 Jul 2005
Posts: 45460
Location: yes

Posted: Fri Jul 18, 14 1:00 pm Post subject:
some wood dusts will spontaneously combust ,especially if a bit warm such as in the bag of my sander twice

Mistress Rose

Joined: 21 Jul 2011
Posts: 15575

Posted: Sat Jul 19, 14 5:31 am Post subject:

To a great extent it is size that determines flammability Dpack. The dust in your sander bag is going to be very fine, being blown around and warm and dry, therefore likely to catch fire. Flour, fine iron filings and few other fine particles will do the same.

I still think the only way to convert properly is by heat and pressure, but mixing the sawdust with something like flour and water paste and forming it to make a block, then drying may work after a fashion.

We have started selling some of our sawdust to a butcher for use in his smoker. Nice to know the bacon I buy is smoked with our sawdust.

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