Prevent Cracking of Walnut Disc

[sheehancolm]

HI everyone,

i am designing a new coffee table for my house. I picked up a nice slab of walnut about 100cm diameter and 20cm thick. It was cut last spring and left out to the elements. there were some small cracks all over the end grain sides as one would expect being left out in the summer heat (even in the UK) and direct sunlight.

TO counter this and create my design i made two cuts. The first took off some poor material on the bottom side and created a flat surface for joining later. The second was a depth cut to create two 10cm pieces. These were both done at a local sawmill. These were just done today. (pics below). I also removed all the bark.

My question to all the experienced guys in here is how to minimize the cracking going forward while it drys out. The freshly cut surfaces have very minor cracks in the middle but other than that they are perfect. I recognize i cant prevent all cracking and don't mind that.

All knowledge/advice greatly appreciated.

Colm

 

[Racers]

Let it dry very slowly and keep your fingers crossed, but its going to split eventually.
A saw cut to the pith from the furtherest away edge should limit the amount of cracking and you could fill it later or leave it as a feature.

Pete

 

[sheehancolm]

Thanks Pete,

I have it in a well ventilated outbuilding at the moment but am wondering if to treat it as well.

All the American forums seem to use solutions like this (Pentacryl) or similar. Anyone have any experience of these. They are not cheap!!

I could make the cut you have mentioned but am slightly worried that the two pieces will dry/shrink differently and ruin the piece.

 

[custard]

I make quite a lot of "live edge" or "waney edge" furniture and get asked all the time to make items like this based on a "salami slice" taken from a trunk. There's no doubt that the demand is there but so far I've always said no because the odds are just too stacked on the side of failure. P.E.G. (polyethylene glycol) is a possible solution but only works with certain timbers and requires total immersion.

Please keep us updated as this project progresses because I'll be fascinated to learn from your experience.

Good luck!

 

[Sam R]

I would anticipate that the join you intend to make will constrain the wood in that area and cause it to crack radially on the unconstrained portions. I doubt much will prevent this. Reasonable recommendations above, you could completely split the leaves and edge join when dry, but perhaps you would be best off just accepting and integrating the fact that it will crack, probably quite severely. It may be worth your time researching George Nakashima's work and methods, if you are not already familiar.

Whilst it may be attractive and in vogue, there is very sound reason for this kind of use of timber having no historical origin. It is mostly a derivation from the so called rustic styles that have emerged en masse since the 1990s (think colour supplements and TV home decor programs), precisely as a reaction to the perfection/uniformity that mass production encourages and demands.

Beyond that, I'm slightly upset that anyone would slice an ENGLISH WALNUT log of that girth rather than plank it. Maybe I'm missing something, hopefully the rest of the tree was rotten and this not possible. Good luck, the wood is lovely.

 

[sheehancolm]

Thanks Sam....couldn't agree more about the wood being cut cross ways rather than longitudinally. however, as it was already cut and relatively cheap i said i would give this technique a go. nothing ventured....nothing gained.

In general the wood is holding up well. I had it outside for about 2 months however, the weather was turning significantly and i didn't think it was going to dry at all in the cold weather. I brought it into the house at the start of December and put it in the coolest room that isn't ever heated. some cracks have developed as expected but nothing major.

to "encourage" the disc to stay together i strapped them up with ratchet straps (2 per disc). i will leave these on until the moisture content has been reduced significantly. they are on seriously tight (i broke one putting it on). not sure if this will help at all but the cracking may be less likely to happen once the wood has dried out. As the whole surface is end grain this should take far less than normal curing.

as this walnut will be dark when finished i plan to fill in any cracks with resin mixed with brass dust to give a gold vein look.

any comments well received.

i have bought a moisture meter (from china) just wondering how will i know when the wood is sufficiently dry on the inside as i can only do surface readings.

I hope to finish it off in a kiln when required.

 

[Rhossydd]

how will i know when the wood is sufficiently dry on the inside as i can only do surface readings.

Weigh it, pop it on some bathroom scales every month or so and record the weight. When the weight stabilises, the moisture content has.
Remember that indoors will be even drier than anywhere outdoors, so it'll take a long time and need to be brought in when it's stable outside and dried further to indoor conditions before finishing.

 

[eoinsgaff]

i think that, unless you go to extreme measures such as PEG, you might be better advised to accept that it will crack unless it is cut. Quartering the sections with a careful line selection might allow it to be reassembled almost invisably.

As stated, George nakashima is an excellent example of what you are trying. However, note the shape of any of the 'salami sections' he uses - they usually have a non circular shape that naturally relieves the stress.

 

[Sheffield Tony]

Whilst it may be attractive and in vogue, there is very sound reason for this kind of use of timber having no historical origin. It is mostly a derivation from the so called rustic styles that have emerged en masse since the 1990s (think colour supplements and TV home decor programs), precisely as a reaction to the perfection/uniformity that mass production encourages and demands.

+1. A big part of woodwork is making a stable piece of work from a material that moves with the seasons. That's why we have framed panels, breadboard ends, etc. And why you don't see many old table tops made from an end grain slice of wood. It will almost certainly crack and split, but if you can design your table so it stays in one piece and enjoy the cracks as character, it's better than using it as firewood !