Spalted Maple

[howlingbaboon]

Hi All,

I've just been donated some Maple logs. Although the tree was felled about a week ago, it was dead and the wood appears to be dry. The owner said that did have leaves last year so must have died over the winter. There appears to be a little spalting on that can be seen on the end grain of some of the logs. I tried turning a small end-grain bowl last night with mixed results (I'll do another post about that so I don't ask too many questions in this one) I've a few questions for you lovely people if you don't mind.

Is this wood likely to be good to turn? Mainly bowls but I'd also like to make a chess set and pieces (white squares and pieces)
Is it likely to need more time to season?
I'm not sure whether to treat it as green or dry

[fuzzyturns]

There are many varieties of maple, and most of them are very good for turning. Here in the UK you are most likely to run either into sycamore, field maple or norway maple, any other species would be ornamental trees. If the tree had leaves last year, then at least some part of the trunk must have been alive then, and that part will definitely need more than a year to season.
Usually there are two ways to go about this:

• if the trunk or branches are still in one piece and you can afford the space, seal the entire end, leave the bark on, cap the ends with cling film and keep it that way until you are ready to work with them. This way the bulk of the wood will stay green with minimised risk of carcking/checking/splitting. Some folks keep their green wood completely wet, by suspending it in a pond or pool. I have even heard of people keeping it in chest freezer. Green wood is much nicer to turn, but once you finished turning, it will move/warp while drying out.
• cut the wood into rough blanks, and rough turn it right away before it had a chance to check/split/crack. The most important thing about rough turning is to keep the wall thickness even all throughout the piece. If you are happy with the wood moving, you can turn to final thickness. If you want to produce perfectly round bowls, these need to dry first and you should keep the wall thickness at roughly 10% of diameter, i.e. 1" thickness for every 10" of diameter. You would then use one of several methods for the drying stage.
  
  • put each item in a paper bag together with some of the shavings. Check moisture content once a week.
  • Seal the end grain of each item with wax or PVA and put in a place with constant temperature and humidity (This is my method and I use a cupboard in the house for this)
  • Use a microwave for accelerated drying. Warning: labor intensive, requires dedicated microwave, mixed results
  • Do nothing and take a chance

How do you know whether it's green or dry? Well, you should be able to feel it. In fact, when you rough turn a bowl of any size from green sycamore or other maple, you should actually get positively wet from all the unbound water flying off. In the long term it's probably best to buy a cheap moisture meter. They are not dead accurate, but they will give you a decent idea of where you're at.

[howlingbaboon]

Thank you so much for your detailed reply. really appreciate it. This may be another clue. The other half of the small log I turned the end grain bowl from last night (see other post). It's only been in the house since late last night. It's splitting so fast I can almost see it happening.

It's already been sawed down into slices unfortunately so it looks like I'm going to have to seal the end grain pretty quickly. It does feel dry and I didn't get wet turning that small bowl (unlike the green Alder I've turned recently)

[howlingbaboon]

I'm not sure exactly which species it was unfortunately. The chap originally thought it was a Sycamore then he thought it was a Maple because he knew it was an Acer. I believe both are from that genus however. He did say it didn't have helicopter seeds though, which puzzled me...

[fuzzyturns]

Judging from the picture, it is probably a sycamore. If the tree was dying, it's no surprise there were no seeds. Not sure how big that log is. From what I can see I'd say somewhere between 4" and 8".

If it's been cut into slices, then yes, take the bark off, seal the end grain and put them on a shelf somewhere dry and not too hot, best in a garage or a shed.
This is always a tricky size of tree. It's too small to really yield useful bowls (which are generally turned from side grain, not end grain) and it's too small to produce much in the way of useful spindle blanks (which should not have the pith anywhere in them). And yes, sycamores do tend to split heavily from the pith.

Best advice from my side would be: phone or email all tree surgeons within a suitable distance from you, there's bound to be one who would be happy to let you have decent size slabs from the trees he takes down for a small fee or even free of charge. All you need then is a couple of square metres of space somewhere in the garden, some concrete slabs, loads of stickers, and a tarpaulin, and you can over time build yourself a nice stack of wood.

[bodrighywood]

I was given some oak a week ago that had been cut down about four years ago. I tested it with a moisture reader and it was still in the red zone. How dry it is depends on the species, where it has been how thick the wood is etc. People say it dries at about 1" a year but IME that is very varied. I rough turn leaving thick enough to re-turn and leave. That way it will dry quicker and easier to store as well.

Pete

[howlingbaboon]

Thanks again for all the advice! I have several logs from that batch, up to around 10". A couple of them will split for face grain bowls. I've slathered PVA on all the endgrain now and just need to remove the bark. I like the idea of keeping it outside under a tarp as my garage is getting chock full with logs now. Going to start processing a little over the next week hopefully.

[burywoodturners]

This raises a question which has had me wondering for a while. Howling baboon tells us that the tree was dead when it was felled. Given that around 95% of a healthy tree is dead wood any way, does it make a difference to us as turners, if the tree was healthy or dead when felled?
Ron