Antique gun springs

[BOB BLACKSHAW 1Participant @bobblackshaw1]

Hello

I am repairing a antique gun which has had a repair in the past, the spring had been cracked at the bend, 320 deg approx end. The crack has been welded and now has lost its spring angle so now has no spring for the hammer. I have bent the spring to the correct angle but can I heat treat this to correct the spring. Or any ideas please.

Bob

[BOB BLACKSHAW 1Participant @bobblackshaw1]

[Bob StevensonParticipant @bobstevenson13909]

Once a main spring has a fault at the bend it’s usually ‘game over’ for the spring as they can never be satisfactorily repaired, as you have seen. Take a couple of pics of the spring lying on the bench with a ruler close beside and send pics to Brownells or a similar gun spares catalogue and see if they can match it, or nearly so…which they probably will. If you have to ‘dolly’ the ends that may well be ok but as a basic rule you can’t work on the main bend successfully……..

[Mick B1Participant @mickb1]

I've recently heard of Numrich reproduction v-springs in the US, and seen pictures of a successful repair using one, but have no further knowledge.

[MarkRParticipant @markr87242]

Mark Novak recently uploaded a video showing him fabricating a new v-spring from scratch, if you can't find a suitable replacement.

https://www.youtube.com/watch?v=PKqNK9CMBxE

[vic francisParticipant @vicfrancis]

Hi Bob, sent a message;, err it will break in time, or be difficult to get the correct strength required… the section would also need care re shaping , not to mention hardening and tempering.What caused the break ?was it someone trying to to remove the spring without skill or material defect or working fault? The taper of the material is very important ! Regards vic

[RobinParticipant @robin]

Those Americans cast folded leaf springs using the lost wax method, Bolek the wheel-lock maker cuts his from lorry leaf springs, Peter Dyson sells bars of spring steel which I have had some success with

[Phil WhitleyParticipant @philwhitley94135]

Problem is Bob that the weld is mild steel wheras the spring is carbon steel. As has been said above, it is game over once it has failed at the bend, but fairly simple to make a new one, provided you have a heat source to get the metal cherry red, and a lump of tool steel. This can be anything that has been hardened (contains carbon), like an old spanner, or any old tool made from carbon steel, but not HSS! Cut a peice of suitable size, heat to cherry red and hold the heat there for 20 mins per inch of thickness, then allow to cool naturally, and it will be soft and workable. Get the steel to the shape required, and then reheat it to put the bend in, and from cherry red quench in oil. Clean the metal to bright polish, and reheat slowly and gently watching the colours, Heat slowly and evenly until the surface colour goes from pale straw, through dark straw, reddish brown, purple and finally deep blue, which is when you pop the spring off the heat and let it cool. You can do this tempering in a sand bath heated from underneath so you can see the colours more easily. It sounds easy, but in practice you may have to experiment with different tool steels to get the desired result. If you have any old car springs handy, the flat type is better than coil springs, this is a good start!

Good Luck

Phil

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