Hand-cut dovetail advice

[Rob Matarazzo]

I've been working on hand-cut dovetails for the past couple of years with maybe a hundred or so dovetails under my belt. My results have been OK but I've been wanting to refine my technique a bit. After reading the ariticle in the current issue of Fine Woodworking, I decided to try some of the suggestions presented. The author recommended scoring the lines for the pins with a knife (tails were cut first) and then sawing these right on the line. This seemed counter-intuitive to me, but I thought I'd try it. My interpretation of this was to put the center of the kerf right on the score line. I ended up with loose-fitting joints, sort of what I expected. Did I interpret this recommendation correctly?

[Derek Cohen]

Hi Rob

You do not saw on the line. You saw to the line ...

http://www.inthewoodshop.com/Furniture/HalfblindDovetailsinJarrah_html_1b83051.jpg

This article in FWW was published 3 years after I presented this technique in my website. I have published several articles since. Here are a couple ...

http://www.inthewoodshop.com/Furniture/HalfblindDovetailsinJarrah.html

http://www.inthewoodshop.com/ShopMadeTools/BuidingaBench4.html

http://www.inthewoodshop.com/ShopMadeTools/BuidingaBench4_html_m2668e9e7.jpg

Regards from Perth

Derek

[David Weaver]

i haven't read the article, but it goes without saying that to get decent accuracy without a whole lot of practice, you'll need to cut your second part of the joint (depending on whether you cut pins or tails first) by cutting on one side or the other of your marked line, whatever is appropriate.

I've never seen much difference in my dovetails scored line or pencil line.

Are you doing anything in particular that would put the odds against you (e.g., cutting dovetails in 1 inch thick white oak to start off?).

[Pat Barry]

Hi Rob
You do not saw on the line. You saw to the line ...
Derek
Using the tape like you have demonstrated is an outstanding idea Derek. It really highlights the part you want to save

[Jim Koepke]

The author recommended scoring the lines for the pins with a knife (tails were cut first) and then sawing these right on the line. This seemed counter-intuitive to me, but I thought I'd try it.

This took me awhile to figure out.

If the pins are marked with a pencil, all of the pencil line is in the area to be retained. Marking with a knife, the line is still at the edge of the mating surfaces.

Another way to look at this… When the tail board is placed in proper alignment on the pin board, when you look between the tails all the wood you see on the pin board is to remain after cutting the pins. Hence, the line stays with it.

There is sawing to a line and there is sawing to split the line. Though most of my saws have a kerf thicker than my sharp pencil lines. For dovetails, whether one does pins first or tails first, the second cut marked from the first piece cut is sawn "to the line." Splitting the line will make for a loose joint.

I saw the FWW issue on the rack and almost picked it up to take a look.

jtk

[Rob Matarazzo]

Hi Rob

You do not saw on the line. You saw to the line ...

...


That is what I would have thought, and why I said the author's suggestion was counter-intuitive. You'd think he would have been a little more precise with his wording for this very critical step.

[Rob Matarazzo]

This took me awhile to figure out.

If the pins are marked with a pencil, all of the pencil line is in the area to be retained. Marking with a knife, the line is still at the edge of the mating surfaces.

Another way to look at this… When the tail board is placed in proper alignment on the pin board, when you look between the tails all the wood you see on the pin board is to remain after cutting the pins. Hence, the line stays with it.

There is sawing to a line and there is sawing to split the line. Though most of my saws have a kerf thicker than my sharp pencil lines. For dovetails, whether one does pins first or tails first, the second cut marked from the first piece cut is sawn "to the line." Splitting the line will make for a loose joint.

I saw the FWW issue on the rack and almost picked it up to take a look.

jtk



This all makes sense when you think about it. Thanks for making me think about it!

[Derek Cohen]

Using the tape like you have demonstrated is an outstanding idea Derek. It really highlights the part you want to save

Thanks Pat. The FWW article referred to by Rob is about using blue tape to mark dovetails (I did not write the FWW article). I've been writing about this technique for some years now. It is an absolute boon for ageing eyes when sawing to lines in dark wood (works in light wood too).

Regards from Perth

Derek

[Rob Matarazzo]

The blue tape seems like a good idea that I'll have to try. The article that I referred to (by Christian Becksvoort) did not mention blue tape, although it is as two-part article of which I only have the second part.

[Derek Cohen]

Aha ... there was an article in the latest FWW by Michael Pekovich using blue tape. I thought you were referring to this.

Regards from Perth

Derek

[steven c newman]

Graduate Class?287516Black walnut is the victim here287517Modified an old "junker" H-F 1/4" chisel, so I could get into all the nooks and crannies. Supposed to look like a miter joint, when done...

[Don Jarvie]

The set of cuts whether they be the pins or tails doesn't matter. It's the second cut the matters. If you use a pencil you should saw so the line shows slightly on the waste side. If you cut the pins or tails first and they are nice and square the other piece should fit pretty well.

[Jim Neeley]

The blue tape is likewise handy when thicknessing a board.

With one side flat, apply the tape all around the perimeter before using your marking gauge to mark the "plane to" spot. It's much easier on tired eyes.


<Running out to buy stock in blue tape companies.> :-)

[Mike Brady]

The way to get better at cutting dovetails is to....cut dovetails.http://i234.photobucket.com/albums/ee300/finefettle/IMG_1171_zpsa385d929.jpg (http://s234.photobucket.com/user/finefettle/media/IMG_1171_zpsa385d929.jpg.html)

The blue tape technique can help you visualize the geometry of the joint but ultimately, eye and muscle coordination depends on repetition. By the way, when using blue tape to lay out dovetails, do you leave the tape on the joint or do you remove it after the joint is put together? Aren't lay out lines a hallmark of hand cut dovetails? If you remove the tape how will anyone know the joint was sawn by hand? Hummmm? I'll hang up and listen for the answer.

[Winton Applegate]

Derek's tape revelation and using a knife on the tape is a great way to go.
That said
if knifing on to/into end grain, (and using no tape) is
FOR ME
a mistake.
The end grain self heals and the line disappears especially on walnut/dark wood.
I prefer, for end grain, pencil or scribing rather than knifing and then rubbing with chalk if it is dark wood.
All this gets planed off in the end after the joint is glued up.
Going pins first when you can allows the pins to be cut without much layout SEE FRANK KLAUSZ DVD and then use the pins to layout on the side of the dovetail board where knifed lines will be much easier to see.
He uses pencil here to. On softer wood.
The harder wood, I think, is best knifed rather than pencil.

[Daniel Rode]

The way to get better at cutting dovetails is to....cut dovetails.

That's what has been working for me. For a recent project, I had 2 drawers that needed half-blind dovetails but I had never cut a half blind dovetail. I spent a couple of weeks doing one joint per night until I got good enough. I even used the same size stock so I could play with the layout as I practiced.

I'm still no dovetail expert but I can make through or half-blinds reasonably well now.

I've used pencil lines, knife lines and knife lines darkened with pencil, I might give blue tape a try next time:)

[Winton Applegate]

Daniel,

Bravo !


I spent a couple of weeks doing one joint per night until I got good enough.

That is the kind of thing I did, with about every thing.
I call it "Playing Scales".

[Derek Cohen]

..... The blue tape technique can help you visualize the geometry of the joint but ultimately, eye and muscle coordination depends on repetition. By the way, when using blue tape to lay out dovetails, do you leave the tape on the joint or do you remove it after the joint is put together? Aren't lay out lines a hallmark of hand cut dovetails? If you remove the tape how will anyone know the joint was sawn by hand? ..

Hi Mike

The blue tape is not used to visualise the geometry of the joint - it is to aid in seeing the transferred lines when these are made on dark wood end grain. Scribed lines in dark wood end grain are both difficult to see and they tend to close up making it even more difficult to see. The blue tape is not used to lay out the tails, only the pins (when you go tails first). (Incidentally, technically speaking, one does not visualise something when it is in full view. One visualises something when it is not in view :) )

Step 1: lay out the tails as you would usually do.

Step 2: saw/chisel out the tails

Step 3: attach blue tape to the pin board end grain.

Step 4: place the tail board over the pin board end grain/blue tape and use a sharp knife to transfer the tails.

Step 5: peel away the blue tape in the waste area.

You are now left with a perfect outline of the tails on the pin end grain. When you saw to to very edge of the blue tape you will end up with a perfect fit.

http://www.inthewoodshop.com/Furniture/TheLastDovetail_html_m6041258d.jpg

I estimated that 95% of these went together without any adjustments:

http://www.inthewoodshop.com/Furniture/TheLastDovetail_html_590ca66b.jpg

Pictorial: http://www.inthewoodshop.com/Furniture/TheLastDovetail.html

You will see that the cut lines (baselines) are still there. I put them in regardless of the blue tape since the tape can come away and the scribed lines are inserted at the start to ensure there is a line to work to if this occurs.

Regards from Perth

Derek

[Jim Matthews]

I believe Gary Rogowski recommended warming up with a single pin and tail before a serious piece of work began.

Every other discipline involves some period or preparation before the main event,
why should wood workers be any different?

While I think a beautifully fitted dovetail is admirable, I'm pleasantly surprised at how
strong the joint is, even on my clumsy efforts.

The amount of surface area exposed to glue is the entire point of having the multiple fingers join,
lots of long grain on either side makes even the most porous connections immensely strong.

My first all dovetail cabinet is square and plumb. It illustrates the value of strategically aligned moldings...

[Winton Applegate]

strategically aligned moldings...

Jim,

Hey now don't leave us hanging like that.
Any chance of a photo please to clarify ?
I am not a big molding man yet so that would help me understand.

[Pat Barry]

My first all dovetail cabinet is square and plumb. It illustrates the value of strategically aligned moldings...
Jim, did you cover all your hard work with a molding?