Freshly Cut Sycamore

[chrisbaker42]

Being a complete novice who has only ever used dry blanks I am in need of some advice. I have acquired a sycamore trunk roughly 250cm x 30cm and as I am collecting it on Sunday need to know what is the best size to cut it to for storage. I would like to try turning some green so any advice for both drying and green turning would be gratefully received.

 

[miles_hot]

Sycamore needs to be stored on end - i.e. not stacked flat on sticks but in an upright orientation otherwise it is given to staining, especially where it is resting on the sticks.

Generally you would keep the bits as long as you can (to minimise the % of waste due to splitting at the ends) and certainly keep the lengths to more than the diameter. Paint the end grain with something (gloss paint, melted wax, end grain sealer, anything really) to reduce the rate at which the wood dries out from the end grain.

I've yet to turn green (something that I am keen to do) however as I understand it a spigot is better as you can keep tightening it if necessary without fear of cracking the wood, wear something waterproof and protect the surrounding workshop from the water spraying off.

If you're going for the warping look (i.e. turning once) you need to go an thin as you dare (for max warpage) but it has to be even (to avoid splits due to different levels of tension). Sanding can be assisted with a hot air gun held above the area being sanded on the rotating lathe.

If you're looking to produce an end product which is round you need to turn it twice - once to a thickness of around 10% of the diameter (and again pretty consistent in terms of thickness but sketch in the intended shape) and then let it dry out (various methods: microwave, store in a plastic bag and keep tuning the bag inside out to release water, in a bag surrounded by shavings, paint end grain and hope) and then turn it again to the final shape and thickness.

In your place I would cut a couple of blanks off the end for my green fun - maybe a big bowl, a natural edge and a smaller bowl - which will take the length down to around 210-200 and then paint the ends on the resulting log and prop it up against a wall taking bits off the end and re-painting as you progress.

Hope this helps

Miles

 

[chrisbaker42]

Many thanks for your comprehensive advice, just what I needed. Without your input I would have made several mistakes in both the cutting and storage.

 

[CHJ]

Being a complete novice who has only ever used dry blanks I am in need of some advice. I have acquired a sycamore trunk roughly 250cm x 30cm and as I am collecting it on Sunday need to know what is the best size to cut it to for storage. I would like to try turning some green so any advice for both drying and green turning would be gratefully received.

In all cases you must seal the endgrain to slow moisture loss as this is where it will evaporate most rapidly and cracks will start to propagate. On most timbers this is minutes not even hours after cutting let alone days.

In log form if you don't expect to use them within a few weeks then leave them in as long a length as possible, then any cracks that do form in each end will only be a small percentage of the log. If they are big enough diameter consider splitting them through the core and seal the ends, do not remove the bark or seal the split face.

If you intend to use the logs within a short period of time or are intending to rough turn them green to speed up the drying then cut them about 1/3 longer than the diameter to reduce risk from end cracks whilst awaiting turning, splittting them through the core and seal the ends will reduce risks, do not remove the bark or seal the split face.

If you cut the logs with a bandsaw to to form a Blank in a rough approximation of a bought item then you need to seal the whole of the periphery, to make sure you have got all the endgrain but not the faces. Don't leave the sealing until another day or even until after lunch if the wood is not partially seasoned.

The slower you can dry the wood the less likely to split, outside on a north facing or sun sheltered rack is good, don't be too worried about some rain getting on it, wetting the outer surface balances the slow migration of inner moisture reducing cracking. However do not leave Laburnum or Cherry exposed to the wet, the sapwood rots rapidly, dry under cover.

Basic need is to let the moisture leave the wood at an even rate all round.

If it dries too quickly from any given surface then the surface wood will shrink and split before inner moisture has a chance to migrate outwards to maintain a balance.

I have only a basic moisture meter but it's good enough for my needs to aid judgment of usability, I find home dried wood that has reached 14-12 % and bellow to be safe to turn without splitting or excessive distortion for bowls and the like, but wood lower than I can measure (bellow 8%) still moves as stresses are released so close tolerance work needs care in selection and turning methods.

 

[Exbomz]

Have a go turning it wet; it is great fun, but do be prepared for a 'sap shower', as already warned! It is really easy on the chisel and I find it the best of all the woods I can get for green turning.

It does stain easily so keep the blanks as big as poss. I've found you can get staining under the seal on the ends - sealing in the damp/spores? - but it doesn't seem to penetrate too far.

 

[chrisbaker42]

Picked up the sycamore today and it weighs a ton, I now have two pieces each about 130cm long and 40cm diameter. I have coated the ends with EVA glue and stood them on end in the garden, I will be putting a plastic sheet over them to keep the rain off but allowing air to circulate.

1. Does this meet with the approval of those in the know?
2. How long should I leave it outside before moving it indoors?
3. How long before I think about using some?

 

[CHJ]

Left stood on the soil in the garden could see it spalting within weeks, not necessarily what you want as it can go very dirty (grey) in colour.

Standing vertically is the best method of keeping it light in colour without staining I believe.

 

[chrisbaker42]

It is stood on the concrete drive leaning against the wall at the top edge so in effect it is only one top edge and one bottom edge in contact with anything. I could probably manage to move in into an enclosed passageway if that would be better.

 

[miles_hot]

Sounds like a good plan - I would make sure that it's not in a howling gale of a draft; after all what's good for drying washing (heat, draft etc) is bad to drying wood as it's too fast. Think in terms of an inch a year to dry outside (i.e. achieve the same moisture level as outside - that's all drying means is gaining parity with the surroundings) but you can bring it inside to come down to the same sort of range that the wood will be used in long before the 4 years is up etc.
Also get cutting the green wood into bowls (rough turned or final thin thickness) as soon as you can = faster drying time and more fun
Miles

 

[chrisbaker42]

Thanks a lot - 4 years seems an age away, never was much on patience - something else to learn along with all the new skills I need to acquire.

 

[CHJ]

Thanks a lot - 4 years seems an age away, never was much on patience - something else to learn along with all the new skills I need to acquire.

For log form it is not always necessary to live by the year rule before touching it for turning needs, in fact in log form the 1 yr per inch may be an under estimation. However as the moisture level drops the risk factor reduces as far as splitting is concerned and you may find it safe to partially prepare and re-distribute storage to speed things up. Unfortunately there is no hard and fast rule and what you end up finding practical in your location and storage methods may be totally different to someone elses.

Time has a habit of passing quickly and experience gained as to what you can get away with soon finds you with bits of wood that you last looked at several years past.

 

[chrisbaker42]

As they say patience is a virtue, I'll leave it covered where it is for a few months and then move it inside before winter comes.

 

[chrisbaker42]

Now 6 months later I have cut the two long logs I had outside into 12 inch logs, painted both ends and bought them inside. Having to wait for one end to dry before painting the other end has resulted in quite a lot of white mould appearing on the wet ends which I have simply wiped off and painted over.

I will keep you updated as to the progress of this wood if it is of any interest to other beginners.