Reclaiming Damaged Components by Welding
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lOUGH welding, at least of ous sheet metals. has become a 211 most garages have the equipd ability to tackle, few concerns s to effect satisfactory welding to heavy castings in iron. aluor Elektron.
such jobs. the actual welding is required is negligible cornith the jigs and machine tools to finish off the work. In to this, large-scale welding can ormed only by highly skilled es who must have either manui' drawings or patterns from work.
the number of specialists able to repairs on seriously damaged such as cylinder blocks are few. these is Angell and Williams n), Ltd.. Sumner Road, S.E.15, ring the past 40 years, have dethe technique for such repairs. More than 75 per cent, of their work is on reclaiming damaged road-vehicle components. Cracked cylinder heads make up a large proportion of the work. but frost-cracked cylinder blocks and fractured sumps also feature in profusion.
An item calling for the highest precision is the repair of oil-engine injection-pump bodies. The normal failure here is wear of the bottom mounting flange or stripped threads in the outlet holes.
For the majority of repairs a fusion welding process is used. The component to be repaired or built-up is placed in a fire-brick-lined oven and heated by gas jets. Welding is effected in the oven, the new metal becoming completely fused with that of the casting.
The oven is then brought up to a set temperature for one hour to ensure even heating of the component, which is left in the oven overnight to cool, thus eliminating the risk of distortion. This system gives an even grain throughout the material and an extremely durable repair.
A sign of the care taken by Angell and Williams in their reclamation work is the incorporation of additional ribs or similar reinforcement in any component which they observe to be subject to a recurrent fatigue failure. In a number of cases these modifications have been adopted by manufacturers and incorporated in later castings.
For repairing items such as gear-shafts. where it is not desirable to subject them to great heat. a cold electro-plating proCe3S is used to build up the worn shaft with nickel to which a small amount of chromium may be added to improve its weLring qualities.
A new service which has been introduced is the supply of reconditioned Perkins cylinder heads for R6, P6 and P4 engines.