My July column for Core77 is now available to read (for free, as always) and discusses what I call the “exploitation” of wood. Here’s the direct link.
The column is, at its heart, about why you should learn everything possible about your raw materials – I seek to know wood as well as I know my wife, Lucy. And it demonstrates how this deep knowledge can be used using three examples from woodworking. In other words, it’s fairly woodworking-y.
The next column will be on the process and strategies I use to design furniture, especially the overall form. Yes, some of this is covered in “The Anarchist’s Design Book.” Some isn’t.
I wrote about the following trick to reduce splitting when nailing in “The Anarchist’s Design Book.” Since then, I’ve caught flack from people who say it’s not true. So much so that I’ve been doubting my own shop experience.
Here’s the problem: When you nail together a piece – especially using cut nails or Rivierre nails – it’s easy to blow out the end grain, reducing the holding power of the nail. Driving a tapered nail is a delicate balance. You need the nail to bite hard, so you don’t want to use a huge or too-long pilot hole. But if you use a pilot hole that is too small or short, the nail will split the work and ruin everything. Oh, you also have to account for the wood species and how thick it is.
It’s a balance of factors to get a good joint. (And that’s why I recommend you make a test joint before nailing together anything – especially if you’ve never worked with a particular brand of nail or species of wood.)
All this is a lot of set-up for…
A common split. This joint was unclamped when I drove the nail.Here’s the joint (a few inches away from the failed joint) after the joint was clamped hard while I drove the nail.
Here’s the Trick If you apply a bar clamp across the end grain of the joint, you can reduce the tendency of the wood to split out the end grain. The clamp has to apply significant pressure for this to work.
Today I tried a variety of strategies as I nailed together a mule chest using 40mm Rivierre nails. All the joints were in Eastern white pine. All the pilot holes were the same diameter (7/64”) and depth (7/8”). And all the holes were located the same distance (7/16”) from the end of the board.
Without a clamp, about half of the joints busted out the end grain (good thing I started at the rear of the chest). When I added a clamp and applied hard clamping pressure – what you would use to close a joint – the failure rate dropped to zero.
I wondered if I needed to have the clamp at full pressure. What if the clamp’s pad simply acted as a wall to prevent the end grain from fracturing? Nope. Clamp pressure – lots of it – was important to keep the joint intact while driving the nail.
I have all sorts of thoughts on why this hard clamp pressure works. But I am weary of theories. If you’ve read this far, give this trick a try yourself in the shop before pontificating in the comments.
Confession: I was greatly relieved that this trick still worked. The internet had made me doubt myself again.
