Re: Linkage repair on a brass locomotive
Daniel A. Mitchell
Good advice.toggle quoted messageShow quoted text
When setting such a rivet one wants to roll the hollow end over into a bead rather like a doubled-over sock. You do not want to just squash it flat. Flattening it may work, but will usually crack the rivet’s new head, and weaken the rivet. This is why rivet-set tools are made.
They form the new head with a smooth sort-of “rolling-over” action (no true rotary motion is involved). Lacking a rivet-set of the correct size, a reasonable alternative is to carefully expand the rivet just a bit with a countersink or other pointed / tapered tool, then work the edge outward and down with a small jeweler’s ball-peen hammer. It’s not as good as using a proper rivet-set, but can be quite satisfactory.
As an aside, this is the same idea as rolling in boiler tubes in a tube-sheet. Here the much larger tubes ARE actually rolled into form with a rotary-roller tool driven by a large air or electric drill. As the tool rotates inside the hollow tube it forces the metal outward then bends and stretches it back over itself forming a bead.
Such a tool would be great for hollow rivets too, but for HO valve gear the parts would be microscopic!