I glued up my toolbox build yesterday afternoon before I left the Penrhyn Castle workshop for home. Multiple dovetails demand your full attention and of course you must drive yourself so as not to procrastinate and so fail to set the tails home into the glued recesses.
Dismantling the original toolbox we’re copying is still an option for me and I may well do that yet. My reason for not is that it’s not really necessary to get to the heart of the man’s methods in making his. Even so, there may be indications I’m missing that I might benefit from and this reasoning tipped the balance in my choosing to do so. I really want to dismantle it because every one of the dovetail joints is no longer glued and can with a little effort be reglued and married to last another 100 years.
Though the sizes of the individual tails (and pins) vary a little, I can see that the maker had aimed at equal sizing and undoubtedly marked them somewhat loosely to size somehow. In the video I am making on this I will be showing different options for layout and sizing and also making and cutting to answer as many questions as I can on this. Here though there are two pretty standard options. One is to split the board equally in size for half pins on the outer extremes or size all pine recesses and outer extremes the same equal size. I did both on mine but generally I never use half pins because most often this makes the outer half pins weak and prone to split depending on the chosen size of the pins. My most general preference for pin size is 3/8” to the outer extremes of the pin recess (the corner) and usually no more than 1/2”. The look neat and have good strength. Finer pins look noce but lack integrity of strength in some wood types.
Tail sizing – Layout I
I decided on following my ancient mentor and laid out with the same 1/4” pin recesses. With 11 tails on the original that meant 12 pins and so, because my box is 12 3/4” wide (or high), deducting twelve 1/4” pins means taking 3” off my 12 3/4” wall width leaving me with 9 3/4” to divide by 11, which is just a whisker over 7/8” per tail. Not an easy measurable fraction but adding a shy 1/32” gave me what I wanted. It is not uncommon for furniture makers to make all tails equal until the last one or find the centre of the board and work out equally sizing the tails until the last two either side and making the last two over or under sized slightly. Quick practical solutions. Of course many tool boxes were made using dovetails that had no layout at all. It simple enough to do this once you are practiced at dovetailing.
Tail sizing – Layout II
Equal sizing of tails is guaranteed when we split the board according to the number of pins but half size the outer pins. It’s quick and simply done.
By using a tape or rule angled across the board to some equal, easily-divided increment you can equally divide any width of board into equal sizing. 12 3/4 may or may not be easy to divide and of course metric is much easier to work with, but moving my tape to a tangent to the 22” mark and marking the two extreme points gives me the start and stop points I need.
A straightedge line in pencil gives me a line to mark increments onto.
In this case 2” increments gives me 10 cross points. These points are the centres of each of the pins and pin recesses that receive them.
These marks now get transferred to the ends of the tailboard piece. I use the combination square to transfer the distances. i can lock the stock on the exact point on the cross-lines and mark them on the corner.
My board is now equally divided into 11 parts. That means ten 1/4” pins and two half pins, on to each side. Marking 1/8” to each side of the increment lines I establish my 1/4” marks for the laying out the dovetail marks with their 1:7 ratio as on the original chest.