I’m interested to see what others say about this. I’m reading “The Foundations of Better Woodworking” right now and the author says that, other than colour, there’s little difference between sapwood and heartwood when building furniture, at least in hardwoods.

The sapwood is responsible for transferring water, sap and other resources around the tree. The heartwood is the structural part of the tree responsible for keeping it upright. Once the tree is felled and dried, there’s little difference between the two.

Quoting: “After a certain number of years have added more and more outer layers, the now-inner layers transition from being active transporters of nutrients to more of a structural role in the tree. This defines the difference between sapwood (the active transport component near the bark) and heartwood (the inner, structural wood), which often have different colors both in the tree and in the wood. While this difference is functionally significant in the tree, and can result in very different relative moisture levels between heartwood and sapwood in a freshly cut board, by the time the board is dried, the differences are mostly cosmetic.”.

(It’s a really good book, by the way – I’m about half way through it and have learned a lot already).

Hope this helps!

George.

I would not say I am an expert on this topic but I would make a couple of points.

1, ‘Sapwood’ varies tremendously from variety to variety. In some woods the sapwood is a totally different texture from the heartwood and I have seen cases where some woods separate along the line where the sapwood meets the heartwood.

2, In Pine there is a large amount of sapwood and although there does seem to be a noticeable difference in texture and density I have never seen a structural problem caused by use of sapwood. In all woods you should account for the sometimes huge change in colour that can take place when using sapwood. Sometimes when you are constructing a piece the wood may look visually quite even with little difference in colour between the the sapwood and the hardwood. However, as the wood ages and changes colour (as pretty much every wood I have ever worked with does) the sapwood may not change much in colour while the heartwood can change dramatically.

This can be especially striking in woods like Walnut where I have seen it very successfully fixed by staining the whole project with walnut stain. Initially this seems silly because the wood is already ‘Walnut coloured’ but it means that later it stays a more even colour.

I hope these points help.

Justjoe wrote:

All the disease fighting things, cant remember what there called, are for the most part kept in the heartwood.

Extractives?

George.