Author Topic: laburnum and cherry  (Read 346 times)

Offline apw99

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laburnum and cherry
« on: March 14, 2020, 08:27:21 PM »
Hi folks, I'm a novice Turner from Kildare in Ireland.
I got my grimey mits on a laburnum tree and a cherry tree today which sadly needed to be cut down.
I am looking for advice on how to dry and store it. Also long will it take to condition?
Thanks!!

Offline Les Symonds

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Re: laburnum and cherry
« Reply #1 on: March 14, 2020, 09:21:58 PM »
Hi and welcome....you lucky so-and-so!
Laburnum has a natural tendency to rot from the pith outwards, so any large logs that show signs of pith-decay can rightly be cut down through the pith then have their ends sealed. They may develop a couple of other longitudinal splits, but I get quite a high yield from laburnum treated in this way. Smaller logs just need to be end-sealed and stored in a dry, airy place for a few years.
Cherry is a very different animal, and can be pushed much harder than laburnum. The photos below are of a 14" x 6" bowl turned from green wild-cherry (Prunus Avium) which was still growing last November and was a little over 40%MC when I got it. Three weeks after felling I rough-turned the bowl,  left it to stand in a garden shed for month, after which time its weight had stabilised, and then finish-turned it. This took away most of the inbuilt stresses in the timber and it simply developed a more organic shape as it dried more thoroughly, which happened quite rapidly. In fact, by early February it was down to 12% and it went off to a gallery. It sold today, so I had a close look at it and sure enough, not a split in sight and its weight identical to what it was the day that I delivered it. This system has worked for 75% of the wild cherry that I've roughed out.

Good luck with the timber....Les
« Last Edit: March 14, 2020, 09:23:49 PM by Les Symonds »
Education is important, but wood turning is importanter.

Offline Tim Pettigrew

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Re: laburnum and cherry
« Reply #2 on: March 15, 2020, 10:17:27 AM »
Cherry is a very different animal, and can be pushed much harder than laburnum. The photos below are of a 14" x 6" bowl turned from green wild-cherry (Prunus Avium) which was still growing last November and was a little over 40%MC when I got it. Three weeks after felling I rough-turned the bowl,  left it to stand in a garden shed for month, after which time its weight had stabilised, and then finish-turned it.

Les, Your drying time for green cherry differs (is much shorter)  than in my experience.  Have a look at THIS data on my website and in particular THIS graph which is fairly typical for a cherry green turning of 160 mm diameter.  I find that weighing is a much more reliable method of monitoring than using a moisture content meter as the mc can vary widely from the surface to the interior of a piece.

Tim
« Last Edit: March 15, 2020, 12:38:30 PM by Tim Pettigrew »

Offline apw99

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Re: laburnum and cherry
« Reply #3 on: March 17, 2020, 11:30:57 AM »
Hi,
Thank you Les and Tim for the very helpful posts, it looks like I have come to the right place! As always one answer spawns a hundred questions so here are a couple to get us started!
- Yes, the laburnum has center rot alright so I will cut it through the pith. What do you recommend to seal the ends? I have some PVA sealer, I assume that would work? Given that we are all staying at home I am not eager to go out an about.

I don't tend to get a lot of turning done and I'm a bit dis-organized as to how long I have held stock, I probably need to sort that out in order to get the best of the this lovely wood. Given that and looking at the chart would a rule of thumb be something like a green bowl of medium size takes about 3 months to dry and stabilize?

Just an aside, but I found my tin of Danish Oil is gone lumpy, any idea why this happens? I tried to dilute some of it with white spirit but it seems congealed. I think the tin may have had a bad seal, have you come by this before?

Lastly (I promise!!) -  what do you use sander sealer for? I imagined it would help with sanding end-grain which won't sand easily. Should the sealer be applied before sanding? Have you any tips for those areas of end-grain which just don't seem to want to sand?

Thanks again guys!



Offline Twisted Trees

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Re: laburnum and cherry
« Reply #4 on: March 17, 2020, 01:33:54 PM »
Apw99

Yes PVA, old emulsion paint, wax, even clingfilm will do it, think of the grain being like porous drinking straws, stop up the ends and it will dry evenly through the sides so doesn't have the inclination to split. If you can't go out then find something you already own to block up those straws!

dis-organised is good, an organised turner is a dangerous thing! drying time is quite variable to air dry a plank the book says about 1 year per inch thickness. But with good airflow warmer room etc. that can change drastically. Best way to see if wood is dry is to weigh it regularly when the weight stays the same then it is dry, BUT you do not always want dry wood, turn the walls of a bowl to even thickness and you can turn it pretty wet, especially with cherry.

I get a lot of wet wood, if it is new to me I will tend to turn it in 3 phases one about a month after getting it, one about 3 months, and one a year or more down the line first one is probably going onto the fire, but I will at least know from that if the wood is worth drying, and as long as you clean up the wet spots from your lathe etc. it can be a lot of fun to turn it wet! 3 months as long as I have prepped it to approximately 1"  wall thickness will often be a usable turning, but will also inform me if I want to wait longer.   

Lumpy danish (or any oil) is usually because of air leak and is usually the tung oil component that solidifies any oil that is made of multiple ingredients needs a good shake to mix it up every now and then, and also doesn't want much air in the tin, I have never found it a problem possibly because it is never hot for long here, but have seen people putting marbles in the tin as they use the oil to keep the air inside to a minimum.

Sanding Sealer is usually used under wax finish, it gives a non or less porous coat to the timber, it should never be used under oil which is designed to soak into the wood. It can also be handy for stiffening up small end grain fibres allowing easier fine sanding of those area's but they have to be pretty much sanded to 300 grit level first. Sanding is an art form in itself, always work through the grit levels never skip one, I start carefully with 120, (some who see my work think I need to start with 40!), I say carefully as 120 will destroy detail as quick as a slipped skew. Then 180 / 240 /  300 etc depending on what I am making it may stop there, or go on to 2000+ if I am using sanding sealer then that would normally go on after the 600 grit, if I am using oil then I may wet sand with oil on 600 grit it really depends on the wood, the cut, e.g. bowl or pen, and a hell of a lot on my mood at the time!
TT, AKA Pete, but that name is taken :-)

Offline Tim Pettigrew

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Re: laburnum and cherry
« Reply #5 on: March 17, 2020, 05:50:34 PM »
Hi,
Thank you Les and Tim for the very helpful posts, it looks like I have come to the right place! As always one answer spawns a hundred questions so here are a couple to get us started!

I don't tend to get a lot of turning done and I'm a bit dis-organized as to how long I have held stock, I probably need to sort that out in order to get the best of the this lovely wood. Given that and looking at the chart would a rule of thumb be something like a green bowl of medium size takes about 3 months to dry and stabilize?

Yes, but drying time does vary considerably according to size.  You can easily take the guesswork out by purchasing some kitchen or postal scales like the ones pictured below

These Abcon scales weigh up to 15kg and are excellent for weighing green turnings.  Note the angled read-out screen which is a good design feature as many of these scales have screens on the same plane as the weighing platform which means the read-out is effectively masked when weighing wide items such as platters. 

As it happens at the moment (17/03/2020) these scales are on special offer on Amazon UK  at 20 GBP (plus shipping). But there are many other similar scales to choose from, some much cheaper.

After rough-turning a green wood item I weigh it and record the weight on this sheet

Whilst the item is drying I weigh it on a regular basis, record the dates and weights on the sheet, until there is no more weight loss.  The item is then transferred indoors to a temperature and relative humidity where it will probably end up being kept.  Again when there is no more weight loss it is ready for re-mounting on the lathe for finishing.  It's probably too fussy a technique for most turners but I've used this for over 10 years now for bowls and platters and it certainly works for me in effectively eliminating warping and cracking in "finished" turnings :) :)  It also gives an excellent insight as to the variation in drying times for various species of wood which I find fascinating.
HERE is a link to a pdf version of the record sheet which can easily be printed.

Hope this is helpful?

Tim
« Last Edit: March 17, 2020, 05:57:16 PM by Tim Pettigrew »

Offline apw99

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Re: laburnum and cherry
« Reply #6 on: March 26, 2020, 05:37:08 PM »
Hi gents,
this is really useful information, many thanks.
I plan to slice and dice the timber for storing this weekend and I may try to turn a few pieces of cherry to see how they come out.

Cheers! Stay safe.