tree stumps

[manco]

anyone ever burn tree stumps out? does it work?

 

[Mick Dempsey]

Not fresh ones from what I have seen.

[openspaceman]

7 hours ago, manco said:

anyone ever burn tree stumps out? does it work?

 

I'm sure I posted the longer version somewhen

[Steven P]

Youtube will show you anything - burning them out, bulldozers and tractors to pull them out, dynamite, all sorts....

 

Depends on the situation I think, but it reckons it will work OK

[Rob_the_Sparky]

Burning wet wood is a right game and I don't see a stump getting dry.  I have seen internet attempts and they have been at it for a day or more feeding a fire lit on the stump.  Seemed to work eventually but why go to all that effort if you can grind it out?

[NJA]

I've tried most methods.  The YouTube methods of pour a teaspoon of fairy dust oil and light it is never going to work.

I had massive piles of brash to burn anyway so had a couple of fires on top of stumps and they went.  

I wouldn't bother if I didn't have loads of stuff to burn anyway and they're not in a location you can have a fire.  I think you need loads of heat for a long period of time, can't see how else you'd do it.

[openspaceman]

35 minutes ago, NJA said:

  I think you need loads of heat for a long period of time, can't see how else you'd do it.

 

Moisture in the wood and surrounding soil makes it difficult because until you can get the wood up to about 300C it won't pyrolyse. Moisture holds the temperature down to 100C. So if the mass of wood and soil conducts the heat away from the fire faster than the fire heats the wood it won't work.

 

My device was a 12 by 38" tractor wheel with a cast iron hub in the middle. An exhaust pipe slid inside the hub onto a  chainsaw bored  hole into the stump. We tried it on the stump of a dead pine we had felled in a garden of a posh new 4 bedroom house. A very old vacuum cleaner blew air down into the hole where the fire was lit. A car wheel with a 5' flue pipe welded to its centre was placed over the exhaust pipe so the exhaust from the fire  was via the flue pipe, this pre heated the combustion air.  The fire burned through the middle of the stump til it reached the sandy soil underneath the stump.

 

It worked but as it took many hours to get up to temperature and then it became uncontrollable it was deemed far too dangerous.

 

I wrote about it here years ago from memory, it happened  around 1980.

 

The house holder was wakened in the early hours by the roar of a jet engine and the bedroom lit by bright orange. A long flame was flaring  from the flue pipe until the vacuum cleaner hose melted. Then it subsided and he cut the power. He was a patent agent and immediately lost interest  in my invention.

 

The fire was out  by the time I arrived in the morning and the laterals had burned out to the edge of the  tractor wheel.

 

I tried it once more on a freshly felled oak stump  but it hardly got going during a day because the wood was so green, it would have needed a support fuel to get it up to temperature, so that was that and most firms earn extras by stump grinding now.