doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Recutting engraving

Mr Ken - when you cut a deep line, you push the graver through the case and actually cut the softer steel below while the case breaks away in small pieces. Since the case is broken, as opposed to cut, there are small, raggedy bits (burrs) left attached. A fine line is an attempt to cut the case layer and it is quite hard. The hard case layer tends to break the graver point.

I think the case layer may add a very small amount of strength to tha action, but wear and corrosion resistance are its real forte.

A little metalurgy for the morning. Just thinking it through. Divergent information welcome.

All steel objects will deflect (bend/stretch/ compress) when a load is applied. The amount of deflection for the load applied is called modulus. Soft and hard steel have nearly the same modulus; this is a counterintuitive point. For example, if I made two identical spring shapes, one of soft steel and one of hard steel, they would perform basically identically as long as I did not deflect them more than the plastic limit of the soft one. However, the hard one would continue to function at higher loads and deflection after the soft one failed in plastic deformation.

Applying the above to an action, the soft core of the action would have to be deflected beyond its plastic limit to have strengthening from the hard case layer. IMO, the core has much more strength than the case. So, if the action were bent beyond the core's plastic limit, the core would overpower the case such that the case could not force the action back to original dimensions. Only if the case layer could force the plastically deformed core back into shape would the case actually add strength beyond its value if soft.

OK, floor is open.

Case hardening adds wear resistance (hardness) and fatigue resistance - at least that is what I remember from a class I took in the seventh decade of the last century. So you would add wear resistanceat the fences, the pin holes, the lever, the safety slide, the knuckle etc... I would think the fatigue resistance would be needed at the interesection of the fence and the water table.

From the class I think I remember coil springs being case hardened for some applications.

Best,

Mike

AM - good points. I think the case could add fatigue resistance because it would have very low deflection relative to plastic yield. Therefore, it would take more cycles to induce a fatigue crack than the softer core - maybe. Agree on wear resistance.

Anneal, recut,,recase harden. Trying to do much more than cut a couple of touchup lines in the work w/o annealing will only lead to a sloppy looking job or matchup (unless the piece is one of the 'colored, but not hardened' variety). Yes carbide gravers will cut through the case but as said the cuts will not look as smooth as the original. Any after polishing, burnishing to smooth out the new work in an attempt to match in with the old will destroy the colors your trying to protect anyway. Very fine cuts that don't pierce the case will be nothing more than misguided scratches in the surface as the tool skates over the casehardening. Tool breakage cutting thru C/H can be frustrating to say the least even with carbide. Being a professional tool sharpener is not the new job status a firearms engraver seeks.
Then there's the after effect of all those bright new cuts that must be colored somehow to match the existing old, aged cuts. Cold blue coated with some gummy shellac anyone??

I can see where a professional engraver will have very little desire to try to pickup a engraving job that will only make him mutter to himself, under his breath. There is enough work these days that it must be nice to tell a client that it should be done right on not at all. Perhaps someone may not mind trying to do it the hard way, if the job is small, and they have nothing else to do. Besides what cost more the engraving or the annealing and then recase coloring? Might be cheaper and faster to just do it the way Ken suggest than pay him extra hours of labor to do it the hard way.

As per Ky Jon ----- and not get a decent job on top of that. Nost engravers I know would run from this type of work because they fear the finished product would damage their reputation. Ken