Porter-Cable 4212 (29550) Half-Pins Vs. Half-Tails, Tearout Reduction, Aligning the Templates

HALF-PINS VS. HALF-TAILS

Traditionally, dovetails have half-pins cut on both ends (Fig. G1). Half-tails will be just as strong, but will not be as attractive (Fig. G2). If your joints are half-tails and you want half-pins, move the vertical board 1/2" either left or right, then move the horizontal board accordingly. The procedure is the same with the 4215 Miniature template, except that you move the boards 1/4".

G1

G2

TEAROUT REDUCTION

Tearout is unwanted splintering of the wood fibers that occurs when a router bit enters, exits, or skims the edge of wood and is common to all dovetail jigs. Tearout cannot be eliminated, but it can be reduced by the insertion of additional scrap wood against the workpiece.

ALIGNING THE TEMPLATES

For proper operation, you must align the templates correctly from front to back. The 4200 series jigs have patented alignment lines to help you align the templates without measuring. Some templates have one line (Fig. H1) while others have several lines to produce multiple types of joints (Fig. H2). Porter-Cable has scribed icons on the templates to indicate which lines go with which joints.

H1

H2

Adjust the templates front-to-back until the alignment line is directly over the point where the horizontal board and the vertical board meet.

NOTE: To be accurate, lean over the template and look straight down to align the lines (Fig. H3).

For the joint to be produced correctly, loosen the knobs on both sides of the template, align the lines, hold the template flat with one hand, and tighten the knobs with the other (Fig. H4).

NOTE: To help align both ends of the template when you are using a narrow workpiece, mount an additional piece of wood (of the same thickness) on the far right (A) Fig. H5.

A

H3

H4

H5

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