View source for Soldered Lap Joint

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=====Description=====

When forming sheet metal into boxes, cylinders or cones for example, it is usually necessary to  join the ends together. This is known as making a [https://en.wikipedia.org/wiki/Hemming_and_seaming '''Seam'''] and the simplest method is to overlap and solder to make a '''Soldered Lap Joint'''. 
[[File:TinsmithingLapJointSoldering2.png|right|400px]]


=====Making the Joint=====

* An allowance equal to the width of the overlap must be added to the length of sheet metal used.
* Ensure the joining surfaces are clean, apply '''[[Soldering Flux|Flux]]''' and bring the pieces together.
* Small pieces may hold themselves together but larger, more complex or 'springy' joints will need to be held in place until '''[[Soft Soldering|Soldered]]'''.
* Use weights, clips, split pins or wire, for example, to stop the pieces moving out of place but ensure that no large section of metal come close to the joint ''(these would conduct heat away and make it more difficult to '''[[Soft Soldering|Solder]]''')''.
* If thin [https://en.wikipedia.org/wiki/Tinning '''Tinplate'''] is used, this is not very conductive and already [https://en.wikipedia.org/wiki/Tinning '''Tinned'''],  so should joint very quickly and easily using an '''[[Electric Soldering Iron]]'''.
* Larger joints in thicker and more conductive materials may need to be '''[[Soft Soldering|Soldered]]''' using  a '''[[Soldering Irons|Gas Heated Iron]]''' - especially if the work is done outdoors.


=====Off-set Lap Joint=====

It is sometimes desirable to have one of the surface left flat and smooth, or  'flush', after joining. This is known as an '''Off-set Lap''' or '''Countersunk Lap''' joint and is achieved by creating a small 'step' along one of the two joining edges with a depth equal to the metal thickness.


[[File:Joggling.png|right|500px]]
A suitable 'step' can be formed by placing a strip of scrap metal under one of the edges and laying down the workpiece on to a '''[[Bench Block]]''' or similar surface. The width of the strip should equal that of the required overlap and its thickness the same as the metal being joined. A '''[[Grooving Iron]]''' can then be struck to set the metal down on to the block and create the required 'step'.


The process of creating the 'step' is known as '''Joggling''' and a specialist tool called a '''[[Joggler]]''' is available to simplify the task.

[[File:TinsmithingCornerLapJoints.png|right|300px]]


=====Corner Lap Joints=====

Both '''Plain Lap''' and '''Off-set Lap''' joints can be configured for corner joints as shown. 


The smooth, or 'flush', surface of all '''Off-set Lap Joints''' can be arranged to be either inside or outside the formed object.  


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[[Category:Skills and Processes]]
[[Category:Sheet Metalwork]]