Hmmm, I doubt about the actual duration of something just 3D printed over, in the sense of adhesion, I remember the process to join (rubber based) watertight ex

Hmmm, I doubt about the actual duration of something just 3D printed over, in the sense of adhesion, I remember the process to join (rubber based) watertight expansion joints and it involved (after preparation of surfaces and application of adhesive) some half hour pressed into a heated aluminium cast. (and the procedure is similar AFAIK for retreading tyres currently in use) On the other hand, they were common in Italy in the '70's and '80's, there were truck tyres that instead of being re-treaded with the "hot" process above were thinned and grooved on a sort of lathe and then a monolithic external "ring" that included the tread on the outside and matching grooves inside was applied, when the tyre was inflated the grooves and the pression made the two stay together (until the tyre was punctured, it was not so rare that you could find on roads these outer rings lost by some truck that had a flat wheel).