Update on chests: halfblind dovetails in Jarrah

[Derek Cohen]

I thought I'd try something new (to me) when dovetailing the drawers.

First of all, here is my dovetailing bench. I set up a moxon vise on an extension table. It is higher than my bench and easier to direct light over the work.

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing1a.jpg

There are 12 drawers in all. All have dark Jarrah fronts. Even with extra directed light, it is difficult to see the lines transfered from the tail board to the dark endgrain of the Jarrah. Jarrah endgrain is hard enough to chop away. Struggling to see the lines makes it hell. 24 sides to do ...

I recalled reading a tip about a year ago that involved using blue tape. I do not recall the name of the individual (my apologies), nor the details of his method - for all I know he was marking through dovetails. Anyway, I thought I would give it a go on the first drawer, and would use it for the others if it helped.

The pin boards were sawn and chiseled in the usual manner. Then it was time to transfer the marks to the pin board.

The pin board was clamped in the vise. As seen, it has a scribe mark to denote the depth of the pins ...

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing1.jpg

The blue tape is added, running between the two boundaries. Cut it away from the sides as the edges will later be needed for registering the tail board.

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing2.jpg

Now you can place the tail board over the pin board to transfer marks ...

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing3.jpg

Remember to use a Vesper knife!!! http://www.sawmillcreek.org/ubbthreads/images/graemlins/yellowsmile.gif

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing4.jpg

It is not easy to see the cut lines ...

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing5.jpg

... until you peel away the waste areas ..

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing6.jpg

The lines stood out so clearly that sawing to the lines was really easy.

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing7.jpg

Here you can see how close to the lines I managed to get ..

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing8.jpg

I've posted this before but I'll show it again. Several years ago, influenced by Tage Frid, I made a "kerf chisel" to deepen the kerf on the half-sawn pins. This has a blade the same thickness the saw. The end of the blade is square to prevent splitting the grain. As a precaution I add clamps to prevent any blow out.

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing9.jpg

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing9a.jpg

The pins were chopped out ...

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing10.jpg

... and the tail board given a trial fit ...

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing11.jpg

That is a nice fit! No adjustments required. Easy peasy.

Regards from Perth

Derek

[bob blakeborough]

Hi Derek,

The tape idea seems so simple, yet is very functional... I am glad you relayed that! It is something I am definitely putting into the "try it out" file...

Can you maybe explain your "kerf chisel" a bit more in depth? I am really interested in that. Did you fab it out of an old chisel?

[Derek Cohen]

Hi Bob

It started life as a stainless steel trowel. Here is an early picture. Since then I have replaced the handle and fine-tuned the blade (thinner, parallel, square ended) ...

http://i13.photobucket.com/albums/a262/Derek50/Tools%20that%20I%20have%20made/Chiselmarkingknife1a.jpg

Here is a more recent picture (at top) ..

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Dovetailblade.jpg

Regards from Perth

Derek

[Chris Griggs]

Thanks for sharing Derek. The tape idea and kerf chisel are very nice tips. I've also seen folks use thin card scrapers and cheap BORG backsaws the same way you use the kerf chisel-the chisel is a definate improvement

[Mike Henderson]

Some good ideas there, Derek. Thanks for posting that.

Mike

[Georg Zudoff]

Hello Derek,

Is this 'stainless trowel' some kind of surgery instrument? And regarding blue tape, merde! but in my country exists only yellow tape ;-))
Instead I've bought today a white pencil in the art-shop. Especially for marking red timber and black ones too.

And as always - brilliant work!

The last one - I try to translate from Russian an anecdote. My mother likes it sometimes. You wrote on your site that you are phisician - paediatric psychologist, if I remember correctly.
My mother is a paediatr (child phisician - sorry, English not my native language) - pulmonology. She is not young, 62 soon, but from time to time she must stay in the hospital for night shift.
In the day after night shift she likes this anecdote. (Apologize if any women will read it).

Two phisicians, men, live the hospital after long and hard night shift.
One of them - Psychiatrist, the other man - ginecologist.

So, they go to the hospital exit, and when they are on the street, they see around and tell each other:
Psychiatrist: - Look, so many normal people around us (normal - with normal mental health)
Ginecologist: - Yes, and all they have faces....

Georg

[Jim Neeley]

That is funny, Georg! :)

[Dave Anderson NH]

On dark woods like walnut or Jatoba I wipe a little powdered chalk into the scribed line. It stands out quite well and the excess can be removed with a damp cloth or paper towel.

[Derek Cohen]

Thanks for the discussion so far. A few points in reply ..

Is this 'stainless trowel' some kind of surgery instrument? And regarding blue tape, merde! but in my country exists only yellow tape ;-))
Instead I've bought today a white pencil in the art-shop. Especially for marking red timber and black ones too.

Hi Georg .. and my welcome to the forum. Great to have your contributions!

The trowel was originally for gardening - you find useful tools for woodworking everywhere! :)

I use white and yellow pencils when marking on dark wood. I gather Rob Cosman advocates using a red ink pen. Now this is fine when it is the initial laying out marks, such as the tails (if you go tails-first, as I do). However, you then cannot mark the pins from the tails using a pencil. Even a fine pencil/ink mark is wider than desired, and there would be too little space to fit a pencil if the tail was narrow to begin. A marking knife is the best solution in this situation.

On dark woods like walnut or Jatoba I wipe a little powdered chalk into the scribed line. It stands out quite well and the excess can be removed with a damp cloth or paper towel.

Hi Dave

I have tried that, and I agree that the lines are clearer. The reason I decided gto try something else here is that the Jarrah endgrain is so hard that even repeated knife strokes (way more than I would want to use as too many just widen the line) are very shallow. I find that the scored lines start to close up very rapidly. That is a nightmare then - you just do not want to try and redo markings by starting all over again, and you do not want to guess where the lines are! One of the reasons I make a big deal out of sawing the tails straight and getting the angles spot on (for most it would not matter as the tails become the master template for the pins), is that if necessary I can use the marking gauge to guide a reinforcing cut line, that is, go over the old line and deepen it afterwards.

By the way, would you refer to the "pin board" (as I tend to do) this way, or call it "sockets"?

Regards from Perth

Derek

[daniel lane]

Dave, that's a great tip I haven't heard before - thanks. Will definitely be trying it, I have a bunch of blue chalk that came with my chalk line. (Anecdote - Recently saw 1 gal jug of chalk line chalk....who USES that much!?!?!)



daniel

[Derek Gilmer]

The kerf chisel is a great idea. I half way through cutting 24 or so blind dovetails. I'll be trying to make a kerf chisel before continuing.

[Derek Cohen]

Hi Derek

PLEASE please please be careful when using this technique, especially on hard and brittle woods! There is always potential for blowing out or splitting the grain. I am not sure what Tage Frid would have written, if he did, but I am confident he would have stated the same.

ALWAYS always use a either a backing board or back support, and clamps on the ends. Hit the chisel gently. Listen/feel the feedback you are getting.

The blade is thin and even in thickness. I would have used a card scraper or a saw blade if it had been possible to add a handle. As it was not, I ground down the blade of a steel trowel. The ends are square. This crushes rather than cuts the small triangle of unsawn kerf. A bevel at the end would act as a wedge!

That said, this is a really helpful strategy for clearing out half-blind pins. Especially, with dark and hard wood where sometimes you feel you are working by feel rather than sight.

Regards from Perth

Derek

[Jessica Pierce-LaRose]

EDIT: never mind, should have refreshed the page - Derek posted before I got around to hitting reply in this window, and answered my question!

[David Keller NC]

Hi Derek - You might want to peruse this blog post by The Schwarz:

http://www.popularwoodworking.com/techniques/joinery/my-first-pair-of-pantyhose

I've seen the blue-tape idea before, though not used quite the same way you have, and I've also tried the pounce bag. Both work on black walnut which has a similar problem to the Jarrah in your post - it's tough to see the lines, and using a white pencil to "darken" the marking knife lines yields unsatisfying results because there's a good deal of wax in the pencil lead. The wax causes the resulting line to smear or skip - you can still see it, but not as precisely as one would like.

The pounce bag has become my standard technique on dark woods. I recently cut a small drawer with an ebony front - without the pounce bag technique, I would've had to resort to my Incra setup on a router table.

[Derek Cohen]

Thanks David

I recall that post of Chris'. Either the idea of spreading powder around did not appeal, or the thought of fighting my wife for her panty hose unnerved me! :)

More pics coming along in a moment.

Regards from Perth

Derek

[David Keller NC]

Thanks David

I recall that post of Chris'. Either the idea of spreading powder around did not appeal, or the thought of fighting my wife for her panty hose unnerved me! :)

More pics coming along in a moment.

Regards from Perth

Derek

As a single guy, I'll admit that the thought of going through the check-out line in the grocery store with a package of pantyhose did not appeal to me. :D

So I used an athletic sock instead - it works just as well. You really should give talcum powder a try - it doesn't interfere with glue or finishes in any way (if powder is present on the wood surface when a film finish is applied, the talc becomes transparent, much like the silica in commercial pore-fillers). Not only does it work very well to mark dovetails in dark wood, but it also works beautifully as a plane & saw lubricant, is way less messy than linseed or mineral oil, and is a lot easier to apply than wax. And using the oils as a plane sole lubricant has the potential to cause finishing problems with certain kinds of film finishes such as laquer.

[Derek Cohen]

Well not quite Emerson Lake and Palmer, but this is music to me. http://www.woodworkforums.com/images/smilies/smile.gif

I've got a long way to go, and I did not get much time this and last weekend. I have the afternoon free tomorrow. Perhaps I will get one or two done, now that the first is completed and the pattern is there.

A while ago I asked advice about dovetail number and sizes. Now you will see what I plan ...

The drawer is complete save for the base. I will do these all later.

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing12.jpg

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing13.jpg

A front ...

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing14.jpg

... and a rear ...

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing15.jpg

Here are images of the slips:

From the rear ...

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing16.jpg

Through the drawer ...

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing17.jpg

.. and internal details (note that the ends are tenoned into the front groove) .. front (on lefty) and rear (at right)...

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing18.jpg

One last item, a jig I used. I had planned to use the drawer opening to square the drawer as the glue dried. However the sides did need a little planing, so I turned to this jig that I got from Andrew Crawford, when I went on a box-making course with him.

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing19.jpg

Just clamp two sides and all four must end up square ..

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Military%20Chests/Dovetailing/Dovetailing20.jpg

Regards from Perth

Derek