# Porter Cable Dovetail Jig 4212



## alanwood (Oct 16, 2009)

Use of Depth setting-I am not sure how to make depth of tail or pin greater than thickness of piece. Is it merely to measure piece thickness and then change depth setting device to allow tail or pin cutter to be greater than the "other" piece?


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## rwyoung (Aug 3, 2008)

alanwood said:


> Use of Depth setting-I am not sure how to make depth of tail or pin greater than thickness of piece. Is it merely to measure piece thickness and then change depth setting device to allow tail or pin cutter to be greater than the "other" piece?


I'll outline what I think is the "easy" way to set up the depth. At the end of the post I have a few thoughts on doing is "backward" from what I describe. It is a little more confusing but it does work.

1) Get an inexpensive marking gauge. I have one of the Shop Fox bras jobs with the cutting wheel on the end. Looks like this: Amazon.com: Shop Fox D2822 Wheel Marking Gauge: Home Improvement But just about any one will do for this.

2) I'll assume you already have your pin and tail boards made and that all the pin boards are the same thickness and all the tail boards are the same thickness. However, it isn't critical that the pin board thickness equal the tail board thickness. Got that? Oh, and have at least one extra tail board and pin board to use as test pieces first.

3) Lets pretend you are going to route the tail boards. Set your marking gauge to the PIN BOARD THICKNESS plus a smidge. How much is a smidge? What I do is about 1/2 the thickness of the marking wheel.

4) Use the gauge to lightly score your tail board test piece. I actually score all the tail boards near where the 1/2 pin cut will be so that the wood fibers on the outside are cut, this minimizes the chipping that can happen later. If you have vision problems or just maybe on the first one, run a pencil through the score to darken it.

5) Place the board into the jig per the jig instructions. 

6) I'll assume you have the dovetail bit and collar installed in your router. Set the router on the jig and adjust the height until you can just catch the outer corner of the carbide in the score line. This is why I like using the marking gauge. Lock the depth.

7) Route your test cut. 

It is nice to have a second router (I don't yet, maybe on black Friday this year I'll get a second one) for using this jig so you aren't playing musical bits. But at least hold your test tail board up to a test pin board and check that the depth of cut is just a little more, 1/32" is great (about 2 playing cards).

The nice think about using the marking gauge (the depth gauge pads on the 4212 have too much flex in my opinion and aren't worth using) is you have that little ridge to catch with the bit and it makes setting the depth repeatably very simple. Plus the light scoring helps with chip out problems because the outer fibers are already cut.

But please, please, don't ever let me catch you bragging that the scoring line left behind is from laying out for that hand cut look!  :blink: You want the hand cut look then hand cut them. :laugh:

This post is getting long but bear with me on one more thought on the dovetails and cutting depth. You have three choices for depth when cutting. First is cutting it perfect so everything lines up in the same plane. It is possible but you spend a lot of time fiddling. Second you can cut the way I outlined above. Simple but you need to remember that you will be loosing a little bit of size and there is the extra step of planing (recommended) or sanding things flush. The third way, and I really like this one, is to cut a little bit shallow so that the face grain is just a 32nd or 64th proud, not the end grain. Why? Because it is easier to plane the long grain down to the face grain of the adjacent piece. Plus, when you are prepping stock, you only need to plane or finish sand the inside faces. The outside faces you do at the same time you are leveling things. And, when clamping, you can clamp right across the joint and get good pressure because you are supporting the clamp face with face grain, not end grain. Clamp marks plus a little squeeze out will get planed off.

In the case of a half-blind for drawers, you can cut the drawer face EXACTLY to length to provide the reveal for your opening and the process of planing down the sides to match (this is assuming it isn't a rabbetted front of course) will save a fitting step in drawer installation.


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## xplorx4 (Dec 1, 2008)

Greetings and welcome to the router forum.


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