View source for Corner Lap Joint

=====Description=====
[https://en.wikipedia.org/wiki/Lap_joint '''Corner Lap Joints'''] ''(aka Rebated Butt, Shouldered Corner, or Angle Lap Joint)'' is useful for joining the corners of boxes, cabinet carcasses and simple drawer fronts for example. It is an improvement on a '''[[Butt Joint]]''' in that it provides two potential nailing or screwing surfaces, more gluing area and reduces the amount of [https://en.wikipedia.org/wiki/Wood_grain '''End Grain'''] exposed.


[[File:CornerLapMainImage.png|400px|right]]
The thickness of the '''Lap''' can depend on whether two nailing surfaces are required for strength, or if it is used to conceal [https://en.wikipedia.org/wiki/Wood_grain '''End Grain'''] or cover the end of a [https://en.wikipedia.org/wiki/Groove_%28joinery%29 '''Groove'''] or [https://en.wikipedia.org/wiki/Rabbet '''Rebate'''] for example.


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[[File:CornerLapScribing.png|200px|right]]
=====Marking Out=====


The '''shoulder''' is marked along from the end of the work-piece either by striking with a '''[[Marking Knife]]''' and '''[[Try Square]]''' or by setting a '''[[Gauges|Cutting Gauge]]''' to the timber thickness.


A '''[[Gauges|Marking Gauge]]''' can be used to mark the thickness of the '''Lap'''.



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[[File:CornerLapCuttingSawGuide.png |200px|left]]

The scribed lines are '''[[Paring|pared]]''' into a shallow 'V' groove to provide a guide for the '''[[Tenon Saw]]''' which is used to cut the shoulders.


Scribing the lines serves to ensure the shoulders have an accurate sharp edge  where they butt up to the surface of the second piece of timber.


[[File:CornerLapCuttingShoulder.png |300px|right]]
=====Sawing the Shoulder=====


The work-piece is firmly clamped to the bench top and  a '''[[Tenon Saw]]''' is guided by the '''[[Paring|pared]]'''  'V' groove to saw down to the lines marking the '''Lap'''.


If additional guidance is required, the scrap piece of timber used to clamp the work-piece can be aligned along the 'V' groove and the saw rubbed alongside it.


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[[File:CornerLapSawingShoulder.png|200px|left]]


It may be necessary when jointing larger pieces of timber to make more than a single saw cut to enable the waste to be removed more easily and accurately. 
[[File:CornerLapChiselling2.png|250px|right]]


=====Paring away the waste=====


Grip the work firmly by clamping to the bench top and use a '''[[Chisels|Wood Chisel]]''' with a '''[[:Category:Mallets|Mallet]]''' to remove the bulk of the waste


[[File:CornerLapParing.png|200px|left]]


Use '''[[Chisels]]''' to '''[[Paring|pare]]'''  away the remaining waste to create the '''Lap''''.


Grip the blade of the '''[[Chisels|Chisel]]''' with one hand ''(thumb on top)'' and grip the handle with the other, to push with a slicing action to '''[[Paring|pare]]'''  down to the marked lines. Vary directions to cope with any difficult [https://en.wikipedia.org/wiki/Wood_grain '''Grain''']. 


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<span style="color: green">'''Note:'''
When '''paring''' with a '''[[Chisels|Chisel]]''' press the back of the hand or knuckles gripping the blade, against the work-piece to improve control and act as a brake.
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[[File:CornerLapBullnose.png|200px|right]]


[[File:CornerLapRouter.png|200px|left]]
To remove waste and level the '''Lap''' on wider boards in particular, a '''[[Planes|Rebate Plane]]''' or '''[[Planes|Shoulder Plane]]''' can be used as shown.


As an alternative to cutting by hand,  a '''[[Router|Portable Router]]''' can be supported on scrap timber equal to the thickness of the work-piece and, with suitable guides in place, the '''Lap''' can  be machined out. 
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<span style="color: red">'''Safety Point!'''
Students may only use a '''[[Router]]''' when they have been trained and assessed and the assessment shows that they are competent, and are under appropriate supervision by specifically trained staff.
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[[File:CornerLapBoxes.png|right|500px]]

=====Uses for a Corner Lap Joint=====
The '''Lap''' can be used not only to hide [https://en.wikipedia.org/wiki/Wood_grain '''End Grain'''] but also to close off features such as a [https://en.wikipedia.org/wiki/Groove_%28joinery%29 '''Groove'''] cut for a sliding lid or a [https://en.wikipedia.org/wiki/Rabbet '''Rebate'''] cut to receive a box top or backing panel for example.


The thickness of the '''Lap''' is varied to suit the depth of '''Groove''' or '''Rebate'''. 


{{Wood Joints Buyers Guide}}

[[Category:Wood Joints]]