Saturday, May 23, 2009

David Charlesworth Comments

On Edge Jointing

In a previous post I was looking at some edge jointing techniques David Charlesworth uses and a few readers made some comments and posted a few questions. I thought it would make much more sense to ask David himself, instead of carrying out another online discussion or thread speculating the how's and why's of his methods with readers. He was gracious enough to drop me a note; if you didn't see the original post you can see it here. Be sure to read the comments there to better understand the topic.


Sorry for the delay in getting back to you, I do appreciate your interest in some of my techniques and the mention of these on your very professional looking blog...

If an edge joint is made with a slightly cambered iron, the glue line when visualised from the end should be slightly thicker at the centre of the joint than at the surfaces.

I think he (Tico) is correct. However if sufficient clamping pressure is achieved, Hoadley suggests something in the order of 200 lbs per square inch, I doubt that this effect will be a problem.
Most medium density hardwoods are somewhat compressible. The original hollow from a slightly cambered iron is of the order of a few tenths of a thousandth of an inch, over the width of a 3/4 inch board.

I would suggest that the hollow in width, could only be a problem if the camber is excessive, i.e. a Scrub plane blade, or if the work was very thick.

The correct place to post this is eluding me but please feel free to post it on the blog.

best wishes,
David Charlesworth


  1. Hi Tom,

    Hey, how cool is this that the man himself checks in! Great fun.
    The camber on the edges of the blade I've used is one that I created following David's technique, and, hence, was not heavy, as a scrub plane blade would be. The resulting hollow on boards for drawer fronts that were 5/8" thick was very subtle, but, as I was looking for it, discernible. I don't think I can get my clients or most others to even see it. They'd probably think I was off my rocker, and would be spot on for suspecting so.

    Your site is professional-looking, as he said. Do you have background experience in this area or somebody special to help you with it? It is a goal of mine to have a website someday.

    Keep up the stimulating posts!



  2. Thanks again for the comments Tico,
    As for the site, it's just me-spending way to much time on my arse in front of this computer!