Close the Mouth

Traditionally, the patch has a trapezoidal form

Repair made with wild olive on beech

Wooden planes offer some advantages in respect to metal counterpart. Between these surely are  the minor weight (then minor efforts) and the easier sliding of plane on the piece; moreover the planed surface normally results smoother.   
The darksides are the easier plane body mouvements caused by weather changments and a minor capacity of resist to wear.

The new patch repalces the old one for closing the mouth

When the sole of a wooden plane wears or has changments in its form, it can be quicly re-levelled. Another plane can be used or a plane surface covered with abrasive paper, too.

The cut must be perfectly orthogonal. 

But, every time the sole is levelled, the funnel form of the throat causes an inevitable event: the mouth enlargement. 
Over time by levelling the mouth, it become too much large and, consequently, the plane has a poor performance.  
It is necessary to remedy by a repair: a patch shaped and glued for a proper mouth closing.  

Prepare the recess

Traditionally, a patch of same wood of the sole is used, frequently an harder wood, for provide an higer grade of wear resistance in the zone in front of the blade cutting edge, inserted as well as an inlay, made internally to the plane sides. 

Smooth the head of the board we will use for preparing the insert.

 This approach provides an elegant solution but of not easy realization; moreover if were necessary to intervent again, to make a patch  of a patch could present some troubleshoting. 
In this specific case I just had to intervent on an old repair and I opted for a slightly different approach.

Cut

I saw some japanese video where, as well as the classic patches and other methods based of mobile elements, an insert extending over all sole width were used, easily replaceable in the case of necessity.  

First, prepare a perfect square piece (10x20 mm will be good), cutting it on the head of a board. 
The piece will be oriented so the head fibers will be exposed on the sole for better wear resistence.

After the position on the sole is traced, cut across the grain for 7-8 mm and level the recess bottom by chisel and router plane. The goal is to create a precise recess for inserting the piece so it can be kept firmly in position without gluing.

By using only glue drops, we avoid a definitive gluing up.

Wait several hours

Some glue drops are sufficinet to insure it in place and, if necessary, they will not impede its eventually future remotion for wich will be enough some chisel shot for pull away the insert. 


Ciao Giuliano

After paring, the mouth appears of right dimensions: 0,4-0,5 mm are good for a smoothing plane.