rabbet trick (or #140 trick) vs. alignment board

[Handplanesandmore]

Derek,

Not to distract the other post on dovetail sawing heights, let me respond to your comments here.

The alignment board is better because there is no need for an additional tool like a rabbet plane, and there is no need to plane the rabbet away in case someone wants it to (what Chris Schwarz mentioned in the Woodwright's Shop episode). Setting the depth and fence for the rabbet plane is also extra work. But most important, the rabbet changes the dimension of the box or drawer, and this can spell disasters for piston fit construction.

Your blue tape method does overcome the last concern, but it has its own concerns. #1, the tape must be laid dead square to the stock, #2, the tape is soft so it does not register against the pin board as securely as a rabbet.

On your remark: The alignment board will obscure the inside intersection (there is no light behind the pin board to be sure),

Can't you shine a light from the top? I have not had any problem positioning the tail and pin boards exactly the way I wanted.

anyone who wants to try - Use an alignment board with a painter's tape laid on the end grain of the pin, knife and peel off the tape. See the marking result for yourself. I may not cut as many dovetails as some of you do (frankly, if I have 10 or 20 dovetailed drawers to make, I'd use a machine like Norm), or as fast as Cosman, but my hand cut dovetails are among the top 10% to 15% in terms of quality.

To be clear, I am not associated with David Barron in any way. Build your own alignment board, no need to buy his. I built all of mine from scraps.

Simon
***
Simon, in my opinion, the rabbet trick (or #140 trick) is better than the alignment board. So there!

The rabbet ensures that the edges butt up against one another. The alignment board will obscure the inside intersection (there is no light behind the pin board to be sure), which was my point earlier. It also limits one to a single - 90 degree - intersection angle. I am not a fan of the rabbet trick (or #140 trick) because it simply adds another dimension where one can screw up alignments. That is the reason I came up with a blue tape alternative:

The #140 trick, as demoed by Chris Schwarz ..

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Regards from Perth

Derek

[Tony Z]

What is the alignment board by David Barron?

[Aram]

Derek,



Your blue tape method does overcome the last concern, but it has its own concerns.

#1, the tape must be laid dead square to the stock,
I've tried Derek's blue tape method. From my understanding of it, this is not true. The "dead square" edge comes from trimming the tape with your marking gauge. Same way you would gauge without the tape. In fact the tape can be laid down any old way, as long as it overlaps the baseline.

#2, the tape is soft so it does not register against the pin board as securely as a rabbet.
Have you tried it? I expected that to be a problem. Then I tried. It wasn't. Three layers of tape makes a surprisingly reliable ridge.

[Handplanesandmore]

Aram,

#1, the tape must be laid dead square to the stock,
I've tried Derek's blue tape method. From my understanding of it, this is not true. The "dead square" edge comes from trimming the tape with your marking gauge. Same way you would gauge without the tape. In fact the tape can be laid down any old way, as long as it overlaps the baseline.

- I stand corrected, as I wasn't relating to the use of the tape with a marking gauge.

#2, the tape is soft so it does not register against the pin board as securely as a rabbet.
Have you tried it? I expected that to be a problem. Then I tried. It wasn't. Three layers of tape makes a surprisingly reliable ridge.

- This may work for smaller boxes or drawers, but for the example Chris Schwarz used (a tool chest?) in the Woodwright's shop, the tape approach would definitely be too unreliable. Chris pushed the rabbeted tail board against the pin with force.

Simon

[Handplanesandmore]

What is the alignment board by David Barron?

Using it -

https://youtu.be/MKcupKHAEcA?t=231

Making one -

https://www.youtube.com/watch?v=5I45mEWAJv4

anyone who wants to make one (by hand or using a power tool), I recommend that you make a wider one so it can cover most widths of the tail/pin boards, say 12" wide or more.

Simon

[bandit571]

Haven't found a use for either "crutch"  while doing dovetails.....

[Admiral]

Haven't found a use for either "crutch"  while doing dovetails.....

Not a crutch, just a technique.

[Handplanesandmore]

Haven't found a use for either "crutch"  while doing dovetails.....

They're just a very very tiny portion of "crutches" people use. The shooting board is probably a better known crutch among others. Robert Wearing who authored a couple of books on the subject is probably the father of modern crutches. Blame him.

 

Simon

[Mike Brady]

I find the relieving of the tails with a #140 is effective, but a needless extra step in the dovetailing process.   Careful sawing and paring is all that is needed to achieve good results, but the small rebate does hide overcuts on the insides of joints.

[C. in Indy]

Aside from the overall necessity question....

If you're making a box/drawer with full dovetails, and you want to accommodate stopped grooves inside, the rabbeting trick is great.

   


Chris