welding vs stitching

[John Delacour]

At 7:02 PM -0800 12/15/01, Joseph Garrett wrote:

>"Stitching" requires some sort of "bondo" to cover the job, in order 
>to make the job cosmetically ok. Whereas, with welding, filing and 
>grinding, then primer, etc.
>....

I don't know what you mean by this, Joe, but I guess you mean you've 
never seen a stitching job or you could not say this.  As I explained 
the other day, the misnamed "stitch" is not the tailor's or the 
draper's stitch, nor yet the protruding tin stitch used to repair 
porcelain.  Very precise drilling and milling of the iron is carried 
out using special proprietary jigs and a precisely made "dumbbell" of 
high tensile nickel is hammered into the prepared location and peened 
flat.  Hardly any filing or grinding is needed to leave a perfectly 
smooth surface.  The colour of the nickel would give away the repair 
to a sharp eye, but certainly not the surface.  This is specialist 
work.


see <http://www.metalock.co.uk/process/process.html> for 
illustrations and description of the process.  You will notice that 
this firm lists welding among its activities but does not mention it 
in connexion with casting repairs.

_________
The Metalock Process is accepted as the method of repairing all 
cracked, broken and damaged castings in Cast Iron, Aluminium and 
Steel for a wide range of industries in a multitude of applications.

The repair consists of peening into prepared apertures, layers of 
Metalock Keys. The Keys are formed into a multi-dumbell shape from 
special nickel alloys. Being highly ductile they can be peened into a 
metal-to-metal condition and become almost integral with the parent 
metal of the component under repair. Metalock Keys are manufactured 
in a variety of sizes to suit each individual job. The high strength 
of the Metalock Keys ensures the return of a high percentage of the 
original strength.

The advantages of the Metalock repair are that no heat stresses are 
introduced, no distortion occurs and in many instances machining is 
unnecessary. It is invaluable in emergency situations, reduces 
downtime and avoids the replacement of expensive castings.

Repairs can be carried out in situ or in our workshops.
________