Thread: How long does timber take to dry

Funny question on a woodwork forum...

For woodworking purposes the rule of thumb is 1 year per inch of thickness, but that is to get it to ambient moisture, I would suggest that the fire would dry the wood very quickly (and during that time it would burn slightly cooler), but once dried - the temp. output should be about the same...

Basically, I reckon once it catches, it will output heat, but wet wood also smokes a lot more.

I hope this helps.

Cam

to get it to dry allow 1 yr for every inch + 1.

therefore a 2 inch thick bit of timber would take 3 yrs. (rule of thumb for timber for furtinture etc ) - thicker timbers take longer longer again if you paint the ends to stop end checking.

for firewood it shouldnt really apply you can burn it wet and it can be cut rough.... - it will burn at the same temperature !! (your comment was a bit funny actually..) but it will take longer to get burning as the water has to evaporate first... and may even refuse to burn if its wet enough...

the reason it burns at the same temp as dry wood is that the flash point is the same (ie 500deg c or whatever) - it just has to get there first.... thats why some people think that tossing petrol on wet timber will work - they get a big flash and lotsa flames until the pettrol is burnt off, you're left with guess what ? wet wood! (minus some small amounts of evaporation).

remember the fire triangle - fuel, oxygen, heat. remove one and no fire!

if you want it to dry faster split it into smaller sections.

cheers

cam beat me to it - however he's slightly wrong - the temp will be the same as I said above.


cheer

Generally I like to leave my firewood at least over the summer to dry.
Yes you can burn some woods ok green, but you will produce less heat and more soot in the chimney.
Split it and stack it outside where the air can get at it, it will dry faster. If you can leave it 12 months it will burn much better.

And it does seem to burn hotter when dry, yes you have to get it to the same temp to sustain a fire, but the dry wood will heat up past that basic combustion temp and give a much better fire as it's not constantly having to evaporate out water.

Cheers

Ian

Yep Zed, I gotta disagree with you and agree with Ianab.

Try mixing metho with water at a 50:50 ratio. The mix will burn, but won't produce much heat. Why? Because all of the heat is being used to evaporate water.

I had a chemistry professor demonstrate this by setting his hand alight. Mind you, in later years he made the mix up slightly wrong and did burn himself slightly doing this.

However, the key is that while the water is evaporating, some of the heat will be redirected to doing that. But that won't take long in the middle of a fire.

Cam

Woodhookers say to stack green firewood so air can circulate for 12 months to get the moisture balance right for burning in a fire. Wet or green firewood is a no-no in a a wood heater as it causes excess creosote build up in the flue and therefore a serious fire hazard.
Cheers

thanks guys that helps alot so it looks like I will be buying firewood this season and will have enough for next year.

Yep. I reckon that Sheddie has nailed it really. It is the smoke that it is issue more than anything.

Cam