Engraving curved surfaces

[Lone Wolf]

After practicing hammer & chisel engraving for two years, I had become fairly confident in my ability to cut some basic designs.  When I engraved my first patch box, it had already been curved to the shape of the buttstock.  What I failed to consider in my two years of practicing on sheet stock was how the curved and rounded surfaces of the patchbox finial would complicate holding the graver at the correct angle to achieve even cuts of uniform depth and width.

Is there a proper technique for engraving on curved/rounded surfaces?

Is it better to engrave an object like a patchbox BEFORE forming it to the shape of the stock?  If so, how do you protect the engraving when shaping and fitting the metal to the wood?

[rich pierce]

I practice on disposable propane canisters for small torches. The curves on patchboxes are pretty subtle.

[Jerry]

Lone Wolf, I always engraved the patch box after it was inletted into the stock. After awhile you will be able to keep the chisel angle positioned for a more uniform cut. In the beginning I would cut everything 
shallow, then make my wide cuts with a 105 or 116 degree chisel. Good luck. Jerry

[D. Taylor Sapergia]

Engraving is keeping the cutter at the correct angle to the surface of the material so that the cut is of uniform depth/width.  This angle becomes a feeling more than a precise hold, so that when you come to cut a curved surface, your hand holding the graver will automatically tilt correctly.  The bow of a trigger guard comes to mind, as does the dome on a patchbox lid.

[T*O*F]

You can also start your first cut in the center and cut half.  Then go back to the center and cut the other half, rather than trying to cut the whole thing in one cut.  Just remember to start the 2nd cut back a bit to establish the same depth.  Everything doesn't have to be cut in one continuous cut.  Good practice for this is cutting script lettering which is done in several cuts.