The #140 trick is dead ...

[Derek Cohen]

.. long live the blue tape trick!


I've been marking and cutting dovetails where the pin- and tail boards are not square to one another. Holding the boards together to transfer tails to pins has been difficult.


I considered the "140 trick", which I first encountered about 15 years ago when Rob Cosman demonstrated it in one of his videos. This consists of a shallow rebate ("rabbet" for you who do not speak Australian or British English) on the edge of the tail board, and it is used to register the tails against the pins.


This method has since been taken up by many, and here is demonstrated by Chris Schwarz (off his blog) ...








It's called the "#140 trick as Rob used a LN #140 skew block plane to plane the shallow rebate (actually shallower than that completed by Chris, above).


During the course of a video I put together recently (the worst video in the world, so don't ask), I have the following idea and actually created it on the spot. I loved the result, and so I have written it up below.


This is an alternative to the #140 trick. A rebate is unnecessary.


This is the tail board, along with cutting gauge and pin board marked with blue tape ..





Set the cutting gauge to the depth of the tail. This may be done when marking, or later ...





Now stretch three layers of blue tape across the base line. It really does not matter how exact you are (I'm rather casual here). All that matters is that the tape is over the line ...





Trim off the excess ...





Now use the cutting gauge to trim the tape to the baseline ...





This is create a fine fence exactly at the baseline ...





The fence acts in the same way as the "#140 trick", except that it may be peeled away afterwards and there is no altering of the dimensions to the board ...





The blue tape on the pin board acts as a non-slip, and the fence is additive in stabilising the two together.


To aid in aligning the boards, I use a simple square made from wood ...





This is placed against the back of the pin board, and the tail board is square off ...





I have removed the square here, but it is not necessary to set it aside ...





The blue tape trick is great when marking dark woods ...





Regards from Perth


Derek

[mike holden]

Brilliant!

[ken hatch]

Derek,

Good tick-tock. As a 140 user and believer I'll give blue tape a go on the next set of dovetails.

ken

[James Pallas]

Good idea Derek. What would us woodworkers do without blue tape and duct tape. Blue tape to mark up, duct tape to hold thinks together after the joints fail.
Jim

[Brian Holcombe]

Interesting approach. I've only ever lined up the corners of my gauge marks with the edge of the board. If it is slightly out it matters very little as the open ends of the tail board are what effect squareness most.

[Jim Koepke]

My feeling on the rebate/rabbet at the base line was it is too much extra work.

The blue tape trick is an interesting work around, but a lot of dovetails would go through a roll real fast.

Recently this trick came my way and was used in making a box out of firewood:

https://sawmillcreek.org/showthread.php?259750

It uses a batten on the tail board to align to the pin board:

Marking Pins.jpg

It just occurred to me the batten could be beveled to hold the tail board at an angle to the pin board, just a thought.

jtk

[Simon MacGowen]

Derek,

While your original blue tape trick for laying out the dovetails is both clever and practical (I still forgot the name of the FW writer who uses the blue tape method a lot in his articles), your "new" blue tape trick is at best trying to reinvent the wheel. Your method relies on accurate placement of the tape as well as careful positioning and alignment of the matching board.

The #104 trick? You can do the same with a batten and a shoulder plane, but the method still requires setting up the plane, etc. Extra work as Jim pointed out. Unnecessary at all...not to mention you need a #104.

The best way under the sky to transfer tails to pins with the least fuss (if you use a jig) is this alignment jig made popular by British maker David Barron: https://www.woodworkersinstitute.com...alignment-jig/

Barron's jig is fool-proof. And this not meant be rain on your parade. No extra plane and no extra tape, nor extra possibilities for (alignment or setting) errors.

Anyone who knows a system that is as fast and accurate as Barron's, please share it.

Simon

[Derek Cohen]

To put this post into context ...

I have never used the #140 trick" and doubt that I ever would. The current build, with the awkward drawer parts to align, forced me to find a way to aid in this regard. I do not envisage using the blue tape as a fence with a standard set up (boards which are square to one another). With the exception of using blue tape to transfer dovetail marks, and my Moxon vise, I have little interest in dovetailing aids.

The issues I have with the Barron jig - which is otherwise a nice idea - are that it is (a) one more jig to store (my little wooden square is more versatile and takes up little space), and (b) in recent years, many of the drawers I have built are curved or angled, and simply would not be helped by the Barron jig. I keep looking for aids to help with my projects. I pass them on with the thought that they may help someone else.

Regards from Perth

Derek

[Tom M King]

Derek is just using three layers of tape to form a fence on the drawer side. There is no accurate positioning required, because he cuts the "fence shoulder" with the marking gauge through the tape. I don't know that any method is faster than the other, including having to build a setup jig for the angled corners of his drawers. Planing a rabbet for the tails probably doesn't take any more time than the tape either, IF the corners were square, but just requires a different setup for marking the depth of the tails. In the end, the method used probably doesn't make a large percentage difference in the time required in building a piece of furniture. If there are many to build, all to the same corner angle, a jig would pay off.

[Simon MacGowen]

To put this post into context ...

(b) in recent years, many of the drawers I have built are curved or angled, and simply would not be helped by the Barron jig. I keep looking for aids to help with my projects. I pass them on with the thought that they may help someone else.

Regards from Perth

Derek

Agreed. Barron's is useful for transferring regular dovetails, not angled joinery work.

Simon

[Simon MacGowen]

The reference to the #104 trick which, like the Barron's jig, is for transferring regular dovetails, created a different impression. Derek has since clarified that his method is more for non-regular dovetails.

Simon

[Derek Cohen]

The reference to the #104 trick which, like the Barron's jig, is for transferring regular dovetails, created a different impression. Derek has since clarified that his method is more for non-regular dovetails.

Simon

I thought I said this in the first two sentences, above, but it must not have been clear enough and eluded everyone.

Regards from Perth

Derek

[Simon MacGowen]

I thought I said this in the first two sentences, above, but it must not have been clear enough and eluded everyone.

Regards from Perth

Derek

This reminds me of a scientific study that found that we tend to take in sensory information and combine it with what we expect, and we extract meaning. That's also why we miss our own typos when we write.

Simon

[Mike Brady]

I get the blue tape method and think it has value, although it is another time-consuming step. I generally get better results if I tape the the pin board (second in my sequence to be cut) and mark with a sharp knife. However, the weakness in this method is also in that step. Look at the second-to-the-last photo above where the pin board and tape are being scored with the knife:
The profile of the tail board that is being transferred is the back (inside) of the tail board, not the show surface. If the tails were not sawed squarely, the joint will have gaps or tightness between the tails and pins. The tape makes the layout easier to see but it doesn't contribute to sawing squarely. If you take extra time after the ails have been cut to square those sawn surfaces as needed, then the transfer of profiles using the tape should minimize errors.

I dislike the Barron guide but it does help keeps things square and give good results on basic dovetail joints. I don't own one by the way.

[Brian Holcombe]

Derek,

While your original blue tape trick for laying out the dovetails is both clever and practical (I still forgot the name of the FW writer who uses the blue tape method a lot in his articles), your "new" blue tape trick is at best trying to reinvent the wheel. Your method relies on accurate placement of the tape as well as careful positioning and alignment of the matching board.

The #104 trick? You can do the same with a batten and a shoulder plane, but the method still requires setting up the plane, etc. Extra work as Jim pointed out. Unnecessary at all...not to mention you need a #104.

The best way under the sky to transfer tails to pins with the least fuss (if you use a jig) is this alignment jig made popular by British maker David Barron: https://www.woodworkersinstitute.com...alignment-jig/

Barron's jig is fool-proof. And this not meant be rain on your parade. No extra plane and no extra tape, nor extra possibilities for (alignment or setting) errors.

Anyone who knows a system that is as fast and accurate as Barron's, please share it.

Simon

I just line up the baseline to the marked line and hold it there while I transfer tails to the pin board. It's fast and accurate, and I don't need to store a jig.

It's good practice for doing work like this:



The case sides are 84" tall and the top is 55" wide, the overall is 16" deep. I couldn't clamp either part in a vise to any worthwhile effect, let along use a jig. I clamped them to the side of my workbench then held the shorter of the two boards in place while I made my marks.

The dark lines you see there aren't gaps but pencil marks.