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Maurice
02-10-13, 16:43
Many of you talk about obtaining wood from tree surgeons etc. How (or do) you dry this timber in order that you can use it for pens? At my age I no longer buy books with lots of pages so leaving wood to air dry for a couple of years may not be a viable option. I have been buying blanks or cutting up spindle blanks that I have bought in the past.

bellringer
02-10-13, 16:51
I cut to pen blank size seal with wax and leave for about a year or two

Woody
02-10-13, 17:15
You can speed the process up by doing what Alex said cut into pen blanks and seal the blanks and bring then in doors in the warm and they will dry out in a few months but you may lose a few to splits I have done this quite a lot with a lot of success I'm 71 and I'm still collecting logs and I see no reason to stop

Neil
02-10-13, 17:36
Maurice,

Depending on what wood it is and in what direction you cut it, ie with the grain or cross cut at an angle to the grain, you will want to cut oversize to your desired pen blank size as it will warp and twist. The amount it will twist will depend on species, whether it is branch wood or trunk wood and its distance from the pith. Wood will, generally shrink around 6-12%% tangentially, 3-6% radially and around 1% along its length. Its often better to cut boards from the tree rather than pen blank spindles as you will retain some of the shape better, but it will take longer to dry. Some woods will tolerate being made into pens wet, Olive for instance is rarely dry, for two reasons, firstly it is very hard to dry and secondly, the Italians in particular have no idea on how to run a country, fight wars or dry wood. Most of the stuff is sopping wet. Turn oak wet and you will end up with a load of matchsticks semi glued to a tube though.

When you do cut wood into thin boards or into pen blanks size spindles you remove a lot of the opportunity for the wood to shrink and build up the stresses which lead to the cracks. I wouldn't bother waxing pen blanks, if they are in danger of splitting through stress build up when they are that size I would rather they did it before I went to the trouble of drilling and putting a tube in it!

When you dry wood one of the most important things to consider is the tempreature and humidity gradient across the drying wood. The steeper the gradient the more stress that will build up as the wood dries, and the greater will be the certainty that it will split. The smaller the section that you are drying the less the opportunity to create a gradient of any significance.

Ive cut Laburnum, alledgedly a difficult wood to dry (no more difficult than any other in my opinion ), into small sections and put it in the oven at a savage 150 for four hours, but if you do this leave it in the oven to go cold. Has worked a treat and Ive never had any problem with retrospective cracking.

Its important to understand why wood cracks or rather it is important to understand how the stresses build up and if you know that you can work around it and if you then appreciate when a wood is going to cup you can compensate for it. If you are going to cut oak for pen blanks and it is wet, always quarter cut it, you will then only have shrinkage at right angles to the grain and you wont get distortion. Cut it through and through and you'll end up with a piece so cupped it'll be worthless.

You can get moisture meters on the internet, they're not very good but for a tenner you cant complain. Most wood when cut is in excess of around 35%, but this does depend on the time of year. Incidentally if you want to cut natural edge blanks for bowls, make sure the wood was felled in the winter, ideally about March. The Cambium layer, that between the bark and the sapwood, is at its strongest in the winter, if felled in the summer theres more than an even chance that the bark will fly off when you turn it, and that's dangerous.

Anyway back to Pen Blanks. There is a guideline widely repeated that it takes a year per inch to dry wood, so a trunk 10 inches wide will take ten years to dry. Cobblers! Its exponential anyway and very much depends on the wood. I've got two fourteen inch diameter yew logs five foot long that I bought when they were eight years felled, and that was four years ago. I took a slice off one last year and the wet ring was clearly visible around four to five inches in. But yew is difficult if not impossible to dry. In days of old they used to tie the trunk to a tree root and throw it into a river to wash the sap out for a year and then dry it. Do you know why they used to tie it on to a tree root?

Yup, otherwise it would have floated away!!

Anyway, a bit off the subject of drying pen blanks but quarter cut the tree and stick it in the oven, my oven stills smells of mulberry, but the wife hasn't a clue what caused the smell!

Neil
02-10-13, 17:39
You can speed the process up by doing what Alex said cut into pen blanks and seal the blanks and bring then in doors in the warm and they will dry out in a few months but you may lose a few to splits I have done this quite a lot with a lot of success I'm 71 and I'm still collecting logs and I see no reason to stop

Did you get that Log of Robinia that Bryan bought up? Was looking for an inspirational natural edge vase from the master.

Woody
02-10-13, 17:46
Yes thank you Neil I keep looking at it so I dont think it will be long now it is one of the things I have to try out to see if I can still do them the last one I tried I got half way down the inside and had to give up but that was before me op so keep your finger crossed LOL

bluntchisel
02-10-13, 19:48
Well done, Neil, for taking the trouble to reply in such an informative fashion.

Get this, you plastic haters - you buy acrylics, slap 'em on the lathe and turn, then you make a pen - all within an hour. With wood you could be pushing up daisies before it's dry! LOL!

Bob.

Maurice
03-10-13, 06:52
Thanks for the info. Have any of you tried the microwave for drying?

Neil
03-10-13, 07:14
Maurice,

I have and am a bit of a cynic. The object of the exercise is to drive the water content from the wood. If you heat it up very quickly, in my opinion, all you will do is to create a steaming piece of wood that will dry through driving off the steam on the surface but remain wet inside. Wood is so dense that driving out the water content from the middle of the wood in a microwave in a short space of time is an impossibility.

Sure your microwave will be steaming and the sense of achievement would be there but put this in perspective, be it an extreme. Recently a very large bog oak tree was discovered in the Fens, it was 13 metres from rootball to first bough, huge. However the size is immaterial. The tree was excavated and slabbed on site and transfered to the Worshipful Company of Carpenters workshops in East London where a kiln was built especially for it. (Read a bit about it here The History Blog » Blog Archive » Ancient 44-foot-long bog oak to make best table ever (http://www.thehistoryblog.com/archives/20209)) The slabs were cut at 60mm and have now shrunk to 38mm, each cubic foot of wood giving up 3.7 gallons of water.

The tree was saturated and the age is irrelevant. But wet wood has so much water in it that sticking it in a microwave and creating a bit of steam is about as effective as painting the Queen Mary with a tooth brush.

Woody
03-10-13, 09:30
I have done it with a bit of silky Oak 6" square x 2" thick the recommended way was short burst of 30 sec on low rest it for about 10 min then repeat and repeat and repeat till dry in the end it go chucked in the wood store with the rest to dry on its own I got fed up farting around with it after about the 6th time and it was still wet wast your time if you wish just to satisfy yourself it may be different with a pen blank but I doubt it your central heating will probably do a better job in a few weeks