The #140 trick is dead ...

[Derek Cohen (Perth Oz)]

.. 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

 

[Just4Fun]

I like it. Rather than cutting a rebate I have been clamping a piece of scrap across the tail board but creating a ridge with blue tape sounds a lot better. I will give it a try.

 

[thick_mike]

Admit it, you have shares in the Blue Tape Co dont’t you?

 

[ED65]

I wasn't aware of the "no 140 trick" previous to this so Derek's (great) new technique is less of a revelation to me

But I actually favour Robert Wearing's approach to the problem.

 

[custard]

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

I don't get it. Why use the 140 trick for a through dovetail?

Actually I'd question the benefit of the 140 trick on half lap dovetails too, but that's an objection in the context of the overall drawer making process.

A well proven method of making a drawer is to first fit the drawer front precisely in the drawer cavity, after that you don't want to alter the width or height of the drawer front during the dovetailing process. Consequently, if you follow this approach to drawer making, you'd arrange for the drawer sides, after dovetailing, to be about 0.5mm proud of the drawer front. Thereby guaranteeing that it's the sides, and not the front, that will get planed down during the drawer fitting process. The 140 trick adds complexity to all that, you'd have to measure the rebate and allow for it when setting out the depth of the pin cuts.

 

[MarkDennehy]

I thought the point of the 140 trick was the alignment of the two boards, the way the dovetail alignment board David Barron advocates does, maybe that's the point of the trick? Not all of us have mastered dovetails yet and it's embarrassing when you cut a dovetail that creates a box where the sides don't meet vertically when they should...

Mind you, blue tape's a bit less expensive than a Lie Nielsen 140 (and the original Stanleys are now more expensive than the Lie Nielsen model...), so I'm glad to know that that even works, I didn't think it would (I've used a Record 778 the few times I've tried that trick, which is slightly less precise and subtle than is required ).

 

[Derek Cohen (Perth Oz)]

Just to be clear, I am not advocating this for every day dovetailing, that is, where boards are easy to align - although there are those who do routinely uses the #140 trick. Rather, it was a way to aid for me, in my current build, in aligning boards that joined in an atypical manner. In this case, at an angle. It did a great job of helping register the parts for marking.

Regards from Perth

Derek

 

[Andy Kev.]

I just tried this on some draw components and it worked a treat, the three pieces of tape providing a very effective fence. Thanks very much for the idea.

Mind you I couldn't resist a bit of heresy: I used yellow masking tape.

 

[StraightOffTheArk]

Mind you I couldn't resist a bit of heresy: I used yellow masking tape.

Burn him!!

 

[Glynne]

Brilliant idea.
I have been known to use the #140 trick but with a router table rather than a plane - to get a uniform depth rebate and crisp edge. But this is so much easier.

 

[custard]

Brilliant idea.

The 140 trick is an interesting technique for dovetailing a box, or dovetailing a carcase. But it has some serious limitations if you want a well fitted drawer. What makes Derek's tape trick so ingenious is that it delivers the benefits of the 140 trick, but without altering the thickness of the tail board in any way.

 

[Bodgers]

What is even better is that blue tape is cheaper than a vintage #140 or a Lie Neilson/Veritas.