Corruption report.

[Random Orbital Bob]

I also use the airing cupboard (our house has a very large one) to simulate kiln drying for blanks I'll be making into boxes. quote]

This raises a point that confuses me about drying versus split avoidance. Both my understanding and experience tells me that the faster I dry my blanks the more they want to split. The whole split avoidance arsenal is in fact aimed at slowing down and even-ing out the drying process: cutting out the pith, sealing the end grain etc etc. 1 year per inch of thickness pus a year etc etc.

So how come kiln drying wood doesn't cause it to split/cup/warp like the clappers??

 

[tekno.mage]

I only use the airing cupboard at the end of my drying process. Freshly felled sticks are split along the pith into halfs or quarters and left outside under ventiltated cover (an open-sided barn) for a year or two. Once cut into blanks, they come indoors to an unheated room where they are weighed regularly. Once the weight of a blank stabilises, it is considered dry enough to use - however as I live in mid Wales (which has fairly high humidity) and may well be making items small boxes destined for dry centrally heated houses, I would then rough turn the box blanks and keep them in the airing cupboard to dry even more before finish turning so that when the arrive in a customers dry hot home the lid will still fit!

Most of the drying is done very slowly, hoping to avoid splitting.

With genuine kiln drying, the pieces are cut into boards before going in the kiln and I would expect that the ends still split, but small splits on the ends of long boards are less of a problem than they would be in smaller blanks.

 

[boysie39]

I like the idea of the toilet roll centres stuffed with shavings, I have a wood burner in the workshop, and have sometimes used shavings to light it. I will have to start saving the centres.

Ahhhh.... <lightbulb shines over head> wonder if they would impress the men at the recycling centre / tip

Instead of biscuits ???

 

[Grahamshed]

I like the idea of the toilet roll centres stuffed with shavings, I have a wood burner in the workshop, and have sometimes used shavings to light it. I will have to start saving the centres.

Ahhhh.... <lightbulb shines over head> wonder if they would impress the men at the recycling centre / tip

Instead of biscuits ???

Of course.
You think not ?

 

[Random Orbital Bob]

I only use the airing cupboard at the end of my drying process. Freshly felled sticks are split along the pith into halfs or quarters and left outside under ventiltated cover (an open-sided barn) for a year or two. Once cut into blanks, they come indoors to an unheated room where they are weighed regularly. Once the weight of a blank stabilises, it is considered dry enough to use - however as I live in mid Wales (which has fairly high humidity) and may well be making items small boxes destined for dry centrally heated houses, I would then rough turn the box blanks and keep them in the airing cupboard to dry even more before finish turning so that when the arrive in a customers dry hot home the lid will still fit!

Most of the drying is done very slowly, hoping to avoid splitting.

With genuine kiln drying, the pieces are cut into boards before going in the kiln and I would expect that the ends still split, but small splits on the ends of long boards are less of a problem than they would be in smaller blanks.

Interesting Kym. And given that approach do you end seal the split sticks or after blank formation or not at all?

 

[tekno.mage]

It depends - I usually seal the ends of cut blanks with PVA once they have been bandsawed and brought inside. I don't normally seal the ends of split logs unless they are "difficult" woods like holly! Sealing the ends of very wet wood with PVA just results in mould growing on the PVA and doesn't seem to give any benefit.

 

[YewTube]

So how come kiln drying wood doesn't cause it to split/cup/warp like the clappers??

Because a kiln controls the relative humidity (RH) and not the temperature.

Splitting occurs when the outside of the wood looses moisture at a higher rate than the inside.

If the heating is controlled to lower the RH slowly then the internal moisture is given time come to the surface so as not to set up a stress gradient.

Bill

 

[Grahamshed]

So how come kiln drying wood doesn't cause it to split/cup/warp like the clappers??

Because a kiln controls the relative humidity (RH) and not the temperature.

Splitting occurs when the outside of the wood looses moisture at a higher rate than the inside.

If the heating is controlled to lower the RH slowly then the internal moisture is given time come to the surface so as not to set up a stress gradient.

Bill

I was wondering as well. Thanks for the answer.

 

[Random Orbital Bob]

thanks for that Bill.

 

[MMUK]

So how come kiln drying wood doesn't cause it to split/cup/warp like the clappers??

Because a kiln controls the relative humidity (RH) and not the temperature.

Splitting occurs when the outside of the wood looses moisture at a higher rate than the inside.

If the heating is controlled to lower the RH slowly then the internal moisture is given time come to the surface so as not to set up a stress gradient.

Bill

+1

Personally I think a better title for the process would be Climate Controlled Drying

 

[Tony Spear]

Local, quite big, tip is only about one mile from us but heavily manned with machine gun turrets and guard dogs. Take a bit of wood ? You must be joking mate.

That's Oxfordshire County Council for you! :evil: