Tag-Archive for ◊ dovetail transfer ◊

Author:
• Friday, April 24th, 2020
dovetail markout

In writings from the 1970s and 80s, Charles Hayward, Ernest Scott and others discuss using shallow saw kerfs to mark the tail layout onto the endgrain of the pin board. The idea is to drag the saw through the tail kerfs, which act as guides. There is no instruction to laterally displace the tail board to compensate for the width of the kerf, and so the intention is to saw to one side of the mark.

I find it difficult to start the cut by following such a mark. Moreover, if the start of the cut is imperfect, it is too easy to become disoriented by the hacked up endgrain surface. I do not like or use this method. 

A better method is to use shallow kerfs to guide the placement and engage the saw as you start to saw the pins. Of course, you must laterally displace the pin board to compensate for the kerf thickness. Otherwise, the sockets will be too wide by the amount of two kerf widths. 

I do not know who first came up with this method. I first saw it on Kevin Drake’s website. More recently, dovetail master Rob Cosman, who mentions that he learned it from The Encyclopedia of Furniture Making by Ernest Joyce, has taught it. I suspect that like most woodworking methods, it has been around longer than we realize. 

In the demonstration photo above, the tail board is shifted one kerf width to the left to prepare for making marks through the kerfs on the right side of the tails. This puts the kerf marks in the waste wood of the sockets on the pin board.

Below, the tail board is shifted to the right for making the marks through the kerfs on the left side of the tails.

dovetail mark out

To gauge the shift, I used a shim that is a tight fit in a kerf made by my dovetail saw. You can regulate the tightness of the joint and/or allow for a margin for error by adjusting the thickness of the shim. Making a slightly thicker shim (say .002″ or a piece of Scotch tape) will make the sockets slightly undersized. This may be good for softer, more compressible woods. 

Make the kerf marks before sawing or chopping out the waste between the tails. This gives you a tighter guide. Note that you have to saw the tails square or at least to a one-sided tolerance.  

You will need a specialized tool to make the kerf marks. With a Western saw, it is impossible to make them on the push stroke, and slow going on the pull stroke unless the wood is quite soft. Japanese saws do not work well for this because the teeth do not extend to the toe of the blade. 

Kevin Drake’s system uses a hawk bill scraper, which acts as a saw with a single big tooth, while Rob Cosman sells a nifty marking tool that is essentially a tiny pull-stroke saw with the same kerf width as his dovetail saw. Note that Drake’s system uses a special dovetail saw with no teeth at all at the toe to aid in registering the saw in the kerf mark. 

Unlike when using a scriber or knife, it is easy to inadvertently shift the tail board when making these pronounced marks in the pin board endgrain. A dovetail alignment board of the sort used by David Barron is one way to minimize this. This tool is a great aid to dovetailing no matter the transfer method you use.  

Another method, is to make a very shallow rabbet (1/32″ is enough) on the inside face of the tail board. This gives a dead-on, steady alignment of the tail board against the pin board. I really like this trick for dovetailing in general and use it especially for wider boards. I recall first learning it from an article by Rob Cosman in Popular Woodworking (April 2006), where he notes that he learned it from Ian Kirby. 

Remember, any method of marking out the pin board goes better if you are working on cleanly sliced endgrain, at least from the table saw or, better, from the shooting board.

So, there you have it: three posts on the critical step of transferring the tail layout to the pin board. I suggest experiment and choose what works for you! My go-to method is still the scriber. I cut my first dovetails 40 years ago but I still like to explore and refine different methods. I’ve only experimented with the kerf mark method, but I may adopt it for some circumstances. I like having options as various woods and constructions favor different methods.

Author:
• Monday, April 06th, 2020
V point marking knife

Continuing the topic of transferring the layout of the sawn tails to the endgrain of the pin board, the purpose of these posts is not to argue for the superiority of any one method but rather to array the options to help you choose what works best for you and the specific project at hand. I vary my method depending on the species of wood, the type of dovetail (e.g. through or half-blind), and the thickness of the wood. 

V-point knives seem to be popular for this task, especially thin models that can slip in between narrowly spaced tails, such as the beauty made by Blue Spruce. Without a doubt, many highly skilled woodworkers produce excellent results with these tools, but I find it difficult to see the knife line. 

I do not mean that it is difficult to see the fine knife line at first, but when I start sawing across the endgrain, I cannot visually keep track of that skinny line to confidently split it with the saw. Chalking the endgrain is not much help. The scriber makes a V-groove that I can track and split better while sawing, and furthermore allows me to better see how I’ve done afterwards. I also find that a V-knife sometimes catches the side grain of the tail, slicing off a hair of it and slightly dislocating the layout line, albeit in the safe direction. 

Ian Kirby, one of my all-time favorite woodworking teachers, has favored a pocket knife for this task. This is not my preference but again, it is another option to consider. The sheepfoot in your three-blade stockman or a Wharncliffe blade like in this lovely Kershaw would be good choices for this because it is easy to reach the tip all the way out to the base of the tail.

Kershaw knife

One knife that I sometimes use is my modification of a Pfeil #13 chip carving knife. I removed the edge and a bit of the width from all but the first 1/4″ of the blade. I also ground the sides to a nearly flat single bevel. (The Pfeil #3 knife would probably also work.) I find this modified tool very easily reaches to the base of the tail and follows the wall of the tail with very little tendency to slice into it. So, I like it better than a V knife but I still usually have the dilemma of following a pretty fine knife line. 

modified Pfeil #13

What about the roll of blue tape in the photo in the previous post? Mike Pekovich, Creative Director of Fine Woodworking magazine, and a very skilled and thoughtful craftsman, covers the endgrain of the pin board with blue tape. (FW #240) He then knifes the tail outlines into the tape, removes the tape over the waste wood, and saws just adjacent to the remaining pieces of tape, which represent the pins. Clever!

I experimented with Mike’s method. It surely has merit, and some will love it, but I am not comfortable with it. The pieces of remaining tape can move, especially if you knick them while engaging the saw, and when they do move, I’m lost. I also do not feel comfortable with a piece of tape determining the registration of the saw. But give it a try, you might like it. 

Next: using saw kerfs as layout.

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Author:
• Tuesday, March 31st, 2020
dovetail transfer tools

A critical step in hand-cut dovetailing is accurately marking out the second piece – usually the pin board – from the completed first piece – usually the tailboard. 

Sure, to make a good dovetail joint, you have to be able to reliably saw to a line and chisel to a line. You also have to understand the mechanics of the joint to appreciate how to tweak the contact surfaces and where you have a bit of tolerance and where you don’t. But if the transfer step is inaccurate, it’s all a losing battle.

So, let’s look at several options

Keep in mind that all of this depends on several variables including pin width, the texture of the wood, and your personal eyesight, lighting, type of saw, and technique. An effective marking out in cherry using a ripcut dozuki may be difficult in red oak using a Western backsaw. 

chisel point drafting pencil

A plain old pencil seems too crude for the precision required in dovetailing and yet it can work well for some. All of the pencil mark is in the keeper wood, so you have to saw to one side of it without touching it at all. A very clean, consistent line gives the best chance for success. A 2mm drafting lead sharpened on 320-grit sandpaper to a chisel point (above) can produce an almost knife-quality line, especially with 2H lead on a diffuse-porous wood like cherry. That said, a pencil is not my preference. 

Starrett scriber

I’ve used a scriber more than anything else for this job, perhaps because that is what I used long ago while learning (first learning, that is). I prefer the type of point on the Starrett scriber (above), which ends in a small, straight conical taper. Unlike a gradual curved taper, I can clearly tell when the scriber is or is not up against the wall of the tail wood. 

Used properly, the scriber point hugs the wall of the tail wood as it bites into the endgrain of the pin board, without any chance of it cutting into the side grain of the tail as a knife might. Thus, the bottom of the tiny V groove created by the scribe point is exactly under the tail wood wall. 

This works best if the sawn (and possibly pared) surface of the tail is straight and clean. Otherwise, the scribed line will be not straight and therefore probably confusing to follow with the saw.  

I have found the scriber effective in ring porous woods like red oak as well as fine, diffuse-porous woods like pear. The downside is the scribed line is not quite as clean and fine as a knife line. 

Next: a look at different marking knives and more.

By the way, go here for my free 42-page Dovetail Instruction Guide that I wrote several years ago for Craftsy. It really gets down to the sawdust and shavings to lead you to success. 

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