We often get extremely worried when heavy machinery parts get damaged. A small crack can stop the whole functioning of the machine. You might want to avoid the method of welding as much as possible due to the large number of problems it encounters. Metal locking is thus an efficient substitute for repairing cracks and ruptures in cast metals.
Mechanical stitching, crack patching and cold welding are some other terms used for this method of repairing cracks. We might often find cracks in the gear box housing of our automobiles or ruptures in the cylinder heads, fly-wheels, pumps, turbines, dryers and other such equipment made out of cast metal. Unless the crack is repaired there is halt in the functioning of machines as it may start leaking therefore terminating the process.
The two main elements of this stitching process are the locks and the stitching pins. Locks are made in various sizes and designs as required by the equipment, and it is installed on the even surface. These locks are then sealed with the pins ensuring stability and a pressure tight seal.
This process of repairing casting cracks involves a number of simple steps. Firstly it uses a drill jig and makes holes perpendicular to the crack. Here each row of holes plays the role of the key. The partition in between the holes is then removed with the help of a chip or chisel. After this the keys are placed into the holes. Then further holes are drilled but this time along the crack, where the screws are placed in between the keys to confirm they overlap thus forming a seal along the crack. Super keys are also used as backup to ensure greater magnitude and a tight grip at the weaker areas.
This method has numerous advantages as compared to the process of welding. Firstly, it is a process of cold repair, so you don't have to worry about deformation of the machine part, unlike welding which uses heat energy. There are various sizes of locks made to suit your requirement. Finally, the work can be done at the site itself without disassembling the machine and liberates you from any expensive replacement of the parts.
Welding should be avoided as much as possible in case of cast iron because it does not expand and often cannot withstand the hardening caused by welding. The heat changes the cast iron itself making it hard enough to cause discontinuity in proper machining. Therefore it is important for you to search for a professional team of workers who are capable of efficiently repairing these casting cracks by the method of stitching.
There exist some engineering service providing companies who boast of professional team workers with years of experience. They are well aware of the latest methods and technology and use them to the fullest for making repairs. They are capable of stitching cracks of the smallest of things from the crank casting of your motorbike up to much bigger hydro turbine runners. Therefore next time when facing such a problem instead of panicking quickly look up for a proficient and experienced mechanical stitching team.
