woodburner and flames - silly question

Mister_G

highrisklowreturn wrote: »

Why essential, and why is a moisture metre essential?

Maybe not totally essential, but the OP is new to stoves and both these items will help maximise the efficiency of the fire for an outlay of about £25.

Also, if it prevents one chimney fire, I would say a good investment.

highrisklowreturn

What causes chimney fires is the flue not being swept for many years - and you can tell how damp a log is by looking at it - if it's begun to crack it's ready to burn.

muckybutt

highrisklowreturn wrote: »

What causes chimney fires is the flue not being swept for many years - and you can tell how damp a log is by looking at it - if it's begun to crack it's ready to burn.

NO - what causes chimney fires is the build up of tar and creosote from incorrect burning of the fuel being used. Soot will catch light yes.

Sweeping the chimney will get rid of the soot and some of the deposits but it is by no means a guarantee that it won't stop you from having a chimney fire. It is recommended you sweep chimneys as a preventative measure to minimise the risk of having a fire, frequency depending upon what you are burning and how often you are burning.

Gloomendoom

We had a chimney fire caused by jackdaws filling the flue with sticks. I should have checked the flue was clear but I didn't. I've not made that mistake again. The chimney stack has a grating over the top now.

suered

Gosh - didn't expect so many people to help - but I should have!

I have an inset stove so nowhere to put a thermometer which is why I was trying to get an angle on how the flames should look.

Skulls - you mentioned swirly, dreamy flames - that's the kind of "life cycle of flames" info I was trying to get. So much online talks about flames "burning vigorously" and gives the impression that they should be doing that ALL the time - but that can't be right, can it? But then if I shut the bottom air vent down all the way (as in handbook) sometimes I don't get flames at all, so then I've been reopening it a bit.

Haven't got a moisture thingy (yet), but next door neighbour says he goes on whether the wood sounds hollow as to whether it's ready to burn.... I ordered a load of wood from his supplier and am still confused - some of it has begun to crack and bark beginning to peel away (thinks dry) but still has green moss on outside of bark (thinks wet). Also, on some of the bits you can see a definite colour gradient from outside to in and I'm not sure if that's indicative of a wet to dry gradient (outer bits are drier than the inner, iyswim) or just a reflection of conditions when the tree was growing?

So many questions..........

Skulls

On most fires you have two sets of vents, top and bottom. You start the fire with the the bottom ones fully open(and maybe the top ones), this should give you the vigourous strong flames. After 10-15 mins, gradually over 10 mins or so, close the bottom vents and keep/open the top ones open. Once the fire is up to running temp maybe 30 mins, maybe one hour, slowly close top vent, NOT TOTALLY, until you should see swirly,dreamy flames. On some burners you will not need to close top vents, on some you can close vents totally, it's trial and error. If the flames start to die at any point, open the vent back to last position.

You will not get the swirly/dreamy flames until the fire is up to working temperature.

All fires are different so it will take a bit of practice to get the vents correct.

Just remember if you have vigourous strong flames, there's too much air being introduced and a lot of the heat is going up the chimney.

If 7 years ago I knew what I now know, I'd still have wood left from about 4 years ago!

Greenfires

Cracking and peeling bark is generally a good sign. Moss can often hang on for a good while, so wouldn't worry too much about that. The hollow sound is another good indicator - wet wood sounds much more "dull" when you knock a couple of bits together.
Quite a few tree species have darker heartwood than the surrounding sapwood, so I wouldn't worry too much about that either.

suered

Skulls and Greenfires, thank you again.

I have top and bottom vents. Booklet and nice HETAS man both say that unless a gale is blowing DOWN the chimney, top vent stays open and control is done with bottom vent.

One of my concerns is when I'm starting the fire I'm maybe closing the bottom vent down too quickly - but sometimes with it fully open the flames are not only up to the "ceiling" of the firebox but arcing over it towards the glass and then I get worried that I'm overdoing it as in too much flame?

Where's an online video of that 12 hour Norwegian programme when you need it? That's what I really want - to watch about an hour of somebody else's woodburner to get an idea of what I should be doing.... Not yet quite on those terms with neighbours tho

Greenfires

What model of stove is it Sue?

Skulls

Bottom vent only stays open if burning coal, for wood this one should be closed when up to temp. If you have a home bargains near you, try out a bag of their kiln dried logs, £3.99 a bag, one of the best seasoned logs I have found. Try the method I have posted and see what works for you.