A priest, upon acquiring a chalice, properly desires to have it blessed or even consecrated. In the Ordinary Form of the liturgy there is only a blessing of a chalice (found in an appendix of the Roman Missal); in the Extraordinary Form, there is a consecration and blessing (found in the Rituale Romanum), during which the bishop (or the priest delegated by him) even anoints the chalice with Sacred Chrism, setting it apart for divine worship in much the same way that the hands of a priest are set apart by the anointing with Chrism during ordination.
(I recommend that any priest try to get his bishop to consecrate the chalice, or request from him the faculty to do so, for it is a far more powerful blessing than the newer one.)
Gold plating wears off chalices, though. When that happens and it is sent off to be re-plated, does that constitute a significant enough change to the chalice that it must be re-consecrated after the restoration work is done?
The 1983 Code of Canon Law does not speak to this topic at all. It speaks about when a church or an altar loses its blessing in a way that is in continuity with the older code of law (1917), but it does not address the matter of how other sacred objects lose their blessing or consecration. To understand how the Church has traditionally treated this topic, we can look at the 1917 Code of Canon Law (especially canon 1305 thereof). And the answer has a surprising twist.
Canon 1305 of the 1917 Code of Canon Law says, “§1 Sacred furnishings that have been blessed or consecrated lose their blessing or consecration: (1) if they have suffered such damage or change that they have lost their original shape and are no longer fit for their purpose; (2) if they have been used for unbecoming purposes, or have been exposed for public sale. §2 Chalices and patens do not lose their consecration when the gold plating wears off or is renewed, but there is a grave obligation to have the gold plating renewed when worn out.” (Translation from the book “A Practical Commentary on the Code of Canon Law” by Woywod and Smith, 1957 edition, page 93.)
The surprising twist is that the commentary goes on from there to note that this was not always how the question had been handled. Up until the 1917 Code of Canon Law, there had been decrees from the old Sacred Congregation of Rites (as recently as 1857) that said that re-plating caused a chalice to lose its consecration; therefore, after the restoration work was done a previously-consecrated chalice would need to be consecrated anew. The 1917 law is a change of praxis on this topic.
So this is what the law said until 1983; now it has fallen silent (strangely) on this topic. The 1917 Code does not bind, but is a useful guide for us to look to when the 1983 Code is silent. Bottom line: if a chalice and paten have not been desecrated, sold, or significantly damaged — if they only need re-plating — then they need not be re-consecrated after that work is done. If they were desecrated, sold, or significantly damaged, then they should be repaired, re-plated, and re-consecrated.
Some will shake their head: there goes Crazy Jerabek with the liturgical hyper-minutiæ again! Oh, but I have encountered this question before. It might not be your question, but it is someone’s. And it has to do with the very objects that contain our Lord’s Precious Body and Precious Blood during the celebration of the Holy Sacrifice — so these details are important like the One whom they serve.