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Dovetailing for Blood!

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Derek Cohen (Perth Oz)

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This is the 14th chapter in the Underbench Cabinet build I have going, here in full (warning, it is long). The earlier chapters are on my website. Scroll down this page to the bottom: Furniture

Note that this is not the usual dovetailing article -it is not a "how to" of dovetailing. Hopefully, it brings forth your techniques for efficiency.

Bill and I have been discussing drawer-making. We have different approaches since our target audience is a different group. Bill is better aligned with production work, aiming to build a drawer as quickly as possible. He is less concerned with aesthetics (although his work always looks exceptionally good) and more focussed on finding shortcuts to increase speedier construction. My work is aimed at being the best I can, with a focus on traditional construction completed to as near perfection as I can muster (which sounds grander in words than in practice!).

I argue that my drawer-making is quite speedy. The speed comes from minimising unnecessary tasks by planning ahead. This is not immediately apparent in that I use techniques that appear to add extra work. In actual effect, they reduce errors and thereby reduce the time required to tune or repair joinery. My aim is to get it as right as possible - immediately. One example if this is that I do not check whether the drawer is square after glue up ... because the drawer will dry in the drawer case, and so fitting the drawer case is what is important.

Now the issue about fitting the drawer case is that this is only possible if the dovetailing is a flush fit, and ready to go into the drawer case. It is expected to be a tightish fit, which will need to receive just a small amount of final tuning. The level of expertise involved here is not really that high; it is more about the approach. I believe anyone can do the same, and this is the motivation to write this chapter. I am sure that Bill will likely do the same ... I look forward to learning from his approach, adding technique to my own.

The discussion started when Bill questioned why I had cut all the drawer parts (sans the drawer bottom) for this cabinet …




Bill makes one drawer at a time. He does this as he is concerned the wood will move .. warp or twist .. if it is allowed to rest. My argument is that speed comes from massed repetition: returning to saw all the parts separately is slow. I do not fear the drawer sides moving as I use quarter sawn timber for drawer sides, which is very stable. The wood here is Tasmanian Oak (which is actually an Australian Eucalyptus).

The drawer-making process is divided into three stages: first comes the (half-blind) dovetailing of the sides to the front. The groove or slips for the drawer bottom is added later.

Secondly, the drawer back is (through) dovetailed to the sides. This relies on the height of the groove, and the reason it is completed later and not up front.

Thirdly, the drawer bottom is made and inserted.

What I wish to demonstrate here is the first stage: dovetailing the front to the sides.

Here are the parts. The Tassie Oak sides are 1/4” (6.35mm) thick and the Jarrah front is 3/4” (18mm).





The inside face of the drawer sides is planed to remove any machine marks ...





We will cut Tails First, so mark the tail board ...





To speed marking of the tails, a template (or story stick) is made. This will set out the tails for the top two rows, six drawers in all.





The tails are sawn. Note that there is a line of blue tape to help my aging eyes know when to stop cutting!





An important step is to undercut the baselines. This will increase accuracy when paring ...





Fretsaw the waste as close to the baseline as possible. I generally leave about 1mm ...





Saw away the half sockets at each side, as usual. But now possible to set the chisel in the chisel wall and use a single down stroke to sever all the waste in the internal sockets, leaving the tail board done.

Mark the web on the drawer front. For 18-19mm drawer fronts, I keep make this 5mm wide.







Once again, to aid visibility, blue tape is applied to underline the baseline ...





... and the pins. Here it extends to the web line ...





This next bit is extremely important, and can make-or-break the final result. The tails are transferred to the pin board. A single bevel knife is preferred. This will hug the wall of the socket, and slice the tape in a single stroke.

Secondly, the tail board is held firmly by a clamp, and is positioned squarely using a combination square. The square is placed along the reference edge, which is the lower edge of the drawer side. This will switch when the other side is marked out. The importance of this technique cannot be overstated: a squared joint is a prerequisite for a perfect fit. Anything that is not square will require planing, and a lot more tuning.





Below is the result of sawing to the line (is the sawing is more accurate than the dropped lines
In practice, the dropped lines are unnecessary if you have a decent sense of plumb) ....





Another time saver comes in the form of deepening the kerfs. This is my version of Tage Frid’s scraper method, a “kerfing chisel”.




With the kerfs deepened, remove all the blue tape, and deepen the base lines ...




Undercut the baselines to create a chisel wall for each socket ...





Chisel in the chisel wall and three moderately firm hammer blows. The chisel wall prevents the chisel moving backwards and over the baseline. This means that chiselling can start at the baseline, itself, and reduces later extra paring ...





Split out the waste ...





With hard Jarrah and a decent Japanese chisel, it takes me three rows to get within 3mm (1/8”) of the web line. I stop at this point ...





This is repeated at the other end of the board ...





Back to the Moxon Vise: the sockets are cleared by paring the remainder in 1mm slices ..





Cleaning out the socket was facilitated by earlier extending the kerfs, and now with a corner chisel ...





It is all about “release cuts”, as David Charlesworth has written in his articles over the years. Create a release cut, and waste will fall away without a fight. The deepened kerfs mean that there is no further paring needed at the sides of the sockets. Clearing the waste is a matter of splitting it out. The chopping is a release cut here.

Finally! The dovetailed sides are tapped into the sockets of the drawer front. The goal here is that they fit “off the saw”, and no further work is needed? Note that the small section here does not only protect the surface, but it ensures it is driven flush ...





How did we do? Here is one side ...




And here is the other side with the “drawer” inserted into the drawer case ...




The drawer can be pushed flush into the drawer case, which was the target at the start ...




Regards from Perth

Derek
 

Just4Fun

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An impressively detailed tutorial. I am heartened to see that the dovetailing techniques I have been tending towards are very similar to what you do. Maybe eventually I will reach your standard.

There are a couple of minor points where my technique differs from yours. Maybe you could comment?

First I have a sequencing question. You mark the base line on the tail board then apply blue tape up against it. I apply blue tape to straddle where the base line will be, then when I mark the base line; this cuts the blue tape and I remove the bit of tape between the baseline and the end of the board. This means my blue tape line is automatically aligned with the base line with no effort or fiddling.

I do the same on the end grain when marking the pins. I cover the whole of the end grain with blue tape, then mark the web, then transfer the tails, then remove the blue tape from the sockets only. This easily gives me a guarranteed accurate blue tape line for the web as well as the sides of the sockets and the blue tape makes it easier to see where to stop sawing the socket sides.
Is there some down side to my approach that I am missing? Any reason why you would not advise doing it this way?

My second question concerns your use of a combination square to ensure the tail and pin boards are square to each other when transfering the tails to the pins board. A couple of years ago I made a rough and ready "dovetail alignment board" that I saw on a David Baron youtube video. I liked it a lot and recently made a better one. I find this an easier & quicker way of ensuring the boards are square and do not move during the marking process. The only risk is if the pins board faces are not parallel but if that happened I think I would have bigger problems to worry about. Have you tried such an alignment board? Any comments?

[Minor edit for punctuation]
 
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Derek Cohen (Perth Oz)

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Is there some down side to my approach that I am missing? Any reason why you would not advise doing it this way?
It is not necessary to be that accurate, and it takes more steps. The blue tape under the baseline is simply to alert me where it is. I can apply it manually accurately enough.

Incidentally, I invented this method ... or, at least, was the first person to write about it as a technique.

A related technique, which does necessitate accuracy, is to add blue tape in place of a rebate ....


This was on my website in 2018, and some wanker plagiarised it and sent the method, almost verbatim (and with the photo), to FWW magazine, who published it in the last edition and paid this fellow for the tip!

My second question concerns your use of a combination square to ensure the tail and pin boards are square to each other when transfering the tails to the pins board. A couple of years ago I made a rough and ready "dovetail alignment board" that I saw on a David Baron youtube video.
David's fixture is clever. However it is too limited for many of the dovetails I need to do. I often make curved or angled drawers, and David's fixture can only cope with square.

This is actually where and why I came up with the tape/rebate method ...



Here is a 2-minute video showing the drawer angles:






Here's another cabinet on the curve ...



Regards from Perth

Derek
 
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Just4Fun

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David's fixture is clever. However it is too limited for many of the dovetails I need to do. I often make curved or angled drawers, and David's fixture can only cope with square.
If I ever reach ninja level I will bear that in mind! Meanwhile, back on planet earth, I will continue with straight & square dovetails and kid myself I am doing OK. Thanks for your response.
 

aebersold

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Lovely work Derek and I can’t see any gaps or filler ! I use a swan Morton knife too and want a single bevel blade as you mention. Do you grind those yourself ?
Alex
 

Derek Cohen (Perth Oz)

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Alex, I like the craft knives. I have a few, and I use these a lot of the time ...



However, when it comes to marking dovetails, I use the best knife for the job. These have single bevels and track against the socket wall. I used to make these knives for friends and as gifts, and then Chris Vesper (who makes the BEST marking tools in the world) asked if he could produce them, which he now does ...



There is also one with an ultra thin blade, which is the only blade I have found to get into the really skinny dovetail I often make ...



Standard thickness blades cannot get in and mark these ...



Regards from Perth

Derek
 

aebersold

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Alex, I like the craft knives. I have a few, and I use these a lot of the time ...
Thanks for taking the time Derek and such a detailed response. I have the factory made knife at the top and it does most marking well, but for dovetails I tilt it slightly to compensate for the bevel. I might have a go at making a single bevel version. Much appreciated,
Alex
 

Derek Cohen (Perth Oz)

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Perhaps I need to explain the title, "Dovetailing for Blood". In part, the description comes from a book, "Backgammon for Blood", by Peter Becker I read about 4 decades ago. It's about taking the game to the most competitive level. This series of articles is not a how-to about dovetailing; it is about the strategies I use when building drawers. I offer them for discussion and your interest.



This is the drawer in question.

In the previous article, the focus was on strategies for connecting the drawer front and drawer sides via half-blind dovetails. The aim there - and continued here - is to complete the dovetailing in such as way that the drawer may be glued up, and dry inside the drawer case. The advantage of drying inside the drawer case is that a good fit is assured.

Today the drawer back needs to be attached with through dovetails.



For interest, here are the chisels I used: Kiyohisa slicks and Koyamaichi dovetail.



Noticeable in the drawer above is that there are no grooves for the drawer bottom. These will now be added using a plough plane and a sticking board to hold the work...





The drawer sides are around 7mm at this stage, with the expectation that they will end up at 6mm. The inside and outside faces have been planed. The groove is 3mm deep ...



The groove in the 18mm thick drawer front is 6mm deep ...



The drawer back receives a shallow groove ...



Reason?

The drawers are designed for a tool cabinet. Unlike drawers for the home, where the backs are lowered, these drawers will have a full rear, in height, ending at the drawer bottom. We start with drawer backs exactly the same dimensions as the drawer front. The lower section needs to be removed. The top of the groove marks this position.

The waste is removed on the table saw, a smidgeon grace ...



... and the machine marks then planed away.

It needs to be stated that drawers are not the same as boxes. While they may both be dovetailed, the drawer width is determined by width of the drawer case. It cannot be larger or be smaller. The drawer front and back are made as a pair, and their dimensions are not permitted to be altered.

With boxes, one can leave dovetails proud, and then level them to the sides. Or one may level the sides to the dovetails. You cannot do this with drawers, especially if the game plan is to aim for the glued up drawer drying in the drawer case. Consequently, the dovetails must end up flush with the surface ....



We move over to dovetailing the rear:

The first step, with 6 drawers of the same height and width, is to make a template for the spacing of the dovetails.



While the template stretches across the board, the area of importance is above the drawer bottom.

Mark out the tails, as usual, but then flip the board so that you are sawing from the inside of the drawer ...



Again, this is not a box. The inside of a drawer is seen, and it is important to keep the baseline as clean as possible, that is, no over-sawing.

Similarly, when removing the waste with a chisel, start with the outside face of the drawer, and finish with the inside. That way there is less danger of inadvertently chiseling over the baseline.



Now ... the interesting part comes with transferring tails to pins. This can make-or-break the drawer.



Here we see the tail and pin boards aligned. But are they?



A square shows that the side is out at least 1-2mm at 300mm (12").



Left like this, the drawer will not sit flat. It will act as if it has a twist. Significant efforts will need to be made to align the drawer in the case. It becomes essential that the side is aligned accurately. This can be a little fiddly, but a long square helps considerably ...



At some point, someone will mention the side-alignment fixture designed by David Barron. This is a wonderful concept, however it excels at making boxes and not drawers. Look here ...

The tail and pin boards are not aligned at the square ends (which would enable David's fixture to be used). They are aligned on the reference side, which is the lower edge of the drawer sides. You are aligning from the left side of these boards ...



Having transferred and sawn the tails, the bulk of the waste is removed with a fretsaw (as detailed before). Here is a reminder - first chop out the waste from the outside face, half way down ...



... and then complete from the show-inside face.

My preference is to angle the chisel slightly away and create a "tent" ...



This is then removed with a slicing paring action, again form each side to the centre ...



Use a narrow chisel to pare the ends: having first sawn these away, the remnants for paring lie above the chisel walls (again discussed in a previous article) ..



This is what we are after: flat ...



Dry fit ...



The drawer must fit the drawer case ...







It does, but we are not finished. More in a while ..

Regards from Perth

Derek
 

Derek Cohen (Perth Oz)

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The aim is to glue up the assembled drawer and let it dry in the drawer case.

This drawer fits ...



... however it is a tight squeeze and I know that there are issues which need to be corrected before glue is applied. It is the same for every drawer.

Each drawer needs to go through an assessment, trouble-shooting for issues, until the drawer moves smoothly.

I need to point out at this stage that, although drawers are made in batches (a row), each drawer is fitted, tuned, and glued up before assembling the next drawer. At this stage, six (of ten) drawers have been completed to this stage. There is one further stage after this chapter.

So we pull the drawer out of the case. It comes out with effort. The sides twist slightly - I can feel one side is moving more freely than the other. Something is causing it to hang up.

Examining the half-blind dovetails, the first item of note is that there is a slightly raised pin ...



Since the drawer is a dry fit, it is a simple matter to knock it apart to make any fixes.

The pin is planed flat.

I note that the one drawer side sits a little proud at the underside, about 1mm ... maybe not even that much ..



This is also planed down.

The drawer back is presented to the case opening ...



It is a tight fit now. It will be a tighter fit later if there is moisture in the air. The drawer back is removed and the height planed down by about 1mm. Re-assembled,
the sides now are higher ...



The sides are planed to the side height ...



I can still feel a little more stickiness on one side. Are the sides flat, or has there a cup developed to create a high spot?

Yes. Slight but it is there ...



Plane this flat. Just a few thin shavings ...



Now the drawer is moving well - it feels taut, but free.

The case is waxed, not so much at this stage to promote ease of movement, but to prevent any glue adhering to the sides ..



Now we are ready to glue the drawer parts. Here are the items involved ...



I am using Titebond Liquid Hide Glue. I like that it has a longer open time, that it is reversible, repairable, and cleans up with water. There is a spatula for application, a fishtail chisel handy if a corner needs to be cleaned, a small mallet, and a wet rag.

The hide glue is decanted into a small bottle ...



This small bottle is a game changer! I was watching Rob Cosman and noted that he used small bottles as well. I found a bunch on eBay. What they do is let you deposit glue in exactly the spot you want to do, and then the spatula lets you spread it around.

I only glue one side of the joint, but there is enough for both sides ...





It is important that the sides are seated flush ...



The drawer looks good ...



... and, importantly, slides into the case smoothly and firmly.

Regards from Perth

Derek
 

foxbat

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Lovely work as ever - thanks Derek for taking the time to post in such detail I really appreciate it
 

Farm Labourer

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You very kindly posted a lesson on dovetailing using your blue tape method several months ago. A real game-changer for me. Thank you!
 

Fred48

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A superbly clear presentation. Love your designs and the amount of information that you provide on your web page. Very informative. Thank you. Alan
 
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