Homemade kiln / fast drying options

[Acer Forestry]

I've seen a few posts here and there about putting together biomass boiler powered kilns out of storage containers and similar. What kind of budget is required for the most basic version, if anyone can advise- i have only had recent access to stacks of chestnut and birch, but need income from the logs now, not next winter; hence the need for rapid drying. Is this a realistic way of drying out firewood in volume, or can anyone suggest any other ways of getting the moisture out fast, thanks

[Pinkfoot]

I got myself a 24 KW workshop stove and a space heater with a thermostat.

I put that lot in a 25 ' refrigerated body and it will hold 49°C..

Dried some apple wood down to <25% in around 10 days.

[big chris the log]

I got myself a 24 KW workshop stove and a space heater with a thermostat.

I put that lot in a 25 ' refrigerated body and it will hold 49°C..

Dried some apple wood down to <25% in around 10 days.

 

Hi is that the moisture content all the way through the log or just as far as the probes penetrate on the outer sides of the log.What are you useing for fans to force the warm air through.

Cheers Chris.

[Pinkfoot]

Moisture readings taken at core.

Space heater has a fan plus a shop floor fan .

Tha fan only drew warm air to the floor to even the temperature.

Floor temperature was 45°C.

The whole lot cost about £1200.

[big chris the log]

Moisture readings taken at core.

Space heater has a fan plus a shop floor fan .

Tha fan only drew warm air to the floor to even the temperature.

Floor temperature was 45°C.

The whole lot cost about £1200.

 

Hi thanks sounds like you have got a good little kiln there for a bargain.

Cheers Chris

[Acer Forestry]

OK, thanks for that- looks like something can be cobbled together for sensible money

[Pinkfoot]

Just be aware that fibreglass likes burning .

Your stove would be better off in its own little insulated metal shed or old prefab concrete garage and the air wafted or blown in to the kiln.

Mine is in the kiln so it takes up room and has to be watched . It is easy to let the temperatur soar with it so be careful.

[Chalgravesteve]

I got myself a 24 KW workshop stove and a space heater with a thermostat.

I put that lot in a 25 ' refrigerated body and it will hold 49°C..

Dried some apple wood down to <25% in around 10 days.

 

Under 25% in 10 days is not exactly dry though? All the stove manufacturers manuals cite under 20% moisture content as being the benchmark.

 

Also, putting a stove which might overheat into a fibreglass body which will burn like hell and release toxic fumes if it goes up, is not a great plan if you have neighbours! The "space heater" is a bottled gas job? Where is the canister for that then? Just outside the fire hazard kiln?

 

I'm not trying to knock the principles of what you are trying to achieve, but if that does go up, and you have the fire brigade in attendance and you have neighbours nearby, you have an obligation to ensure that your installation is safe and a gas bottle in close proximity to what you already accept is a potential fire hazard is unsafe. If you are drying the wood for resale, ie as a business, then you are putting yourself at risk as you are responsible for the safe working practices.

[Pinkfoot]

Perhaps the space heater is diesel .

I don't remember saying that <25%was dry but having said that , I think it is plenty dry enough. It burns fast enough and easily enough.

I do accept that fibreglass is not the material to have a stove in and I shall move it out of there..point taken.

[Chalgravesteve]

Perhaps the space heater is diesel .

I don't remember saying that <25%was dry but having said that , I think it is plenty dry enough. It burns fast enough and easily enough.

I do accept that fibreglass is not the material to have a stove in and I shall move it out of there..point taken.

 

I only made the point on 25% MC as the OP wanted to build a kiln that dried wood comparable to the biomass ones. It is all relative as if your wood was 50% + to start that's not bad going. It all depends on what you want the finished product for, and if it is for resale then 25% isn't going to hit the well enough I don't think.

 

The space heater, if it paraffin, propane, operates with a live flame and a blower and then left unattended to run in a fibreglass area could be very bad. Like I said, I'm not trying to defeat the objectives here, simply put a word of warning that any DIY system needs to have safety considered. In the same way that most DIY things get over engineered, the same should apply to making sure its a safe job as well.