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Cracked or broken Metal Casting repairs by cold ...
Service > Casting Repairs
Leicestershire, United Kingdom

Cracked or broken Metal Casting repairs by cold metal Stitching to Aluminium / Cast Iron by Surelock For Sale


Last updated: 3 weeks, 4 days ago

Cracked or broken Metal Casting repairs by cold metal Stitching to Aluminium / Cast Iron by Surelock Casting Repairs MIDLANDS


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The Surelock Metal stitching repair is a proven and reliable method of repairing Cast Iron and Aluminium Cylinder Heads and Blocks, However, almost anything can be repaired such as Heavy Machine Beds to holes in crankcases There is no heat used at any stage of the procedure. Therefore, eliminating the cost of re-machining and rebuilding. It is possible for Surelock to use this method on site at your premises

We also exhibit at motor shows and race meetings across the UK so perhaps enquire come and see us with your casting repair problem

Surelock casting repairs was founded in 1966 and is a forerunner in specialist repairs of fractured and holed crankcase and cylinder blocks ( Aluminium or Cast Iron) by the process called Cold metal stitching.

No heat is applied at any stage, so that distortion is kept to a minimum, thus allowing engines, etc, to be repaired if necessary in situ and with the minimum of strip-down.

On site engineers are available to carry out in situ - repairs in the UK or WE WILL VISIT EUROPE. These repairs are backed by in house complete cylinder block and head reclamation services, including, pressure testing and ceramic sealing.

The majority of Surelock's work comes from recommendation, past on by satisfied clients, from De dion, Alvis, Jaguar, ERA Remus, Rolls-Royce, Veteran and Vintage owners to Commercial Truck and Heavy Industry Companies


The Surelock repair consists of preformed metal keys which have the same characteristics of expansion and contraction as the parent metal. These keys are inserted across the fracture using a Jig to drill a series of holes to which you then knock the centres out to create a shaped keyway, you then fit the lock into the keyway and repeat this part of the process at set intervals along the fracture when this is done the gaps between the locks are drilled and tapped to accept bolts these are tightened and chiselled flush to create a single repair. Then the whole repair is riveted with a cross pein sealing the fissure. An absolute pressure tight repair is achieved by chiselling the repair flush with the parent metal and then going over it with a smooth pein and to finish, lightly polish the area with a grinding stone.

Once this has been achieved, where applicable the item is pressure tested to check the repair and also make sure the rest of the casting is pressure tight then as a final check the area is crack tested. The method Surelock use is called non destructive testing (NDT). A white quick drying background paint is applied to the test area, then a magnet is attached and a graphite solution is washed across and the magnetic flux picks up fractures. Once all this has been done the warranty is raised....

As Featured in Thoroughbred and Classic Cars magazine - March 2001 Issue

A stitch in time
Surelock can literally stitch your engine back together if it blows.

If you race an historic car you put ancient components under great stress, and it's not unheard of for con-rods to make a bid for freedom through the side wall of your engine block. Or say you're restoring a rare car that's stood unloved for years, and its cylinder head has cracked through frost damage. Replacement can be difficult and expensive. So where would you go to have the original repaired? America? Italy? How about a one-man operation in a tiny workshop in England's oldest county: Rutland.

'I've got a truly international clientele,' says Nick Hood, proprietor of Oakham-based cold-metal stitching specialist Surelock. 'What I do here is a dying art. People can't easily get something like this properly repaired anywhere else.' He points to a Delage engine block with a quarter-inch wide fracture stretching almost the whole length of its outer wall.

The way you might expect to repair a crack in an iron casting is by welding, but Surelock's method is entirely mechanical and involves no heat. Nick explains: 'Welding involves pre-heating a block or cylinder head to 600 degrees celsius and, while it will repair the crack, it will also distort bores, block oilways, ruin coolant channels and destroy bearing journals. What you're left with will need a great deal of machining to make good. Cold metal stitching simply heals the fracture and leaves everything else alone.'

The process involves drilling a line of holes through a template across the crack at right angles to it, and then knocking out the webs between the holes. This creates a caterpillar-shaped channel, into which specially-made nickel alloy rods - 'locks', as Nick calls them - perfectly fit. The process is repeated at intervals along the fracture, and the gaps between the locks drilled and tapped to accept bolts. Nick then tightens in the bolts, chisels off the bolt heads flush with the parent metal, and cross-peens the locks and bolt-shafts until the fissure is completely filled.

An absolute seal is achieved by further smooth-peening and then the whole assembly is pressure-tested to three times its usual working limit. The finished result literally looks like a row of stitching, but is imperceptible to the touch. Says Nick: 'You can paint a block after it's been repaired and nobody would ever know, but many owners leave the repair undisguised. Each one tells its own story.'

Holes are treated by cutting out the affected area and patching in new metal, fixing the join exactly the same way as stitching a crack. The technique is equally suitable for cast iron or aluminium alloy.

'I've got a real variety of work at the moment, from Rolls-Royce 20hp cylinder heads to blocks from a Vintage Renault and De Dion to MG T-type and racing Talbot,' says Nick. 'As a guide, I could repair cracks around the valve seats of an Austin-Healey 3000 for £250, or stitch a six-inch block fracture for £300. And I'm not tied to the workshop permanently. Some repairs can be done in-situ. I've repaired a crack in the block of a Singer Le Mans without even removing the engine. That cuts down the cost of stripping down and rebuilding.'

Surelock was founded in 1970 by Nick's father, Bev, and employed 14 people at its peak, when the company's repair techniques were employed in many industrial applications. Nick learned his skills from Bev and took over in 1991, scaling down the operation to specialise in repairing historic racing car engines. He's also completed many other projects, including the counterweights for a flood barrier, which had sheered.

One particularly memorable job was two years ago. 'We had an Osca racing car in, just been rebuilt, and the restorers had blown the engine during testing. It was due to take part in a parade lap at Le Mans. At the last minute, we stitched it and they rebuilt it. Its owner drove it straight down to Le Mans, took it round the circuit and drove it all the way home again. It never skipped a beat.'

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