Yes... and no.
We size rings all day, every day, right here in our shop.
If a ring needs to be larger, we determine the karat (or metal type) and add that metal to the ring. We then add the appropriate solder in the process.
A little about solder:
There are Hard, Medium and Easy solders. Hard solder melts (or 'flows') at the highest temperature and Easy solder flows at the lowest temperature. We like to use a Hard solder because it wears better and provides a stronger connection.
Here's the thing about soldering: You don't actually put solder on a piece of jewelry, then melt it with a torch. Actually, you heat the piece you're working on to a point that it gets so hot that it causes the solder to melt. This is how you contol where the solder goes, by where you're directly heating the piece. The solder follows the heat. This is where skill and experience come into play.
Here's a problem:
Some goldsmiths will use an Easy solder when working on jewelry. This is understandable, asit makes the job much easier and safer fro the goldsmith. As you can imagine, when working on something as thin and delicate as a hollow rope (for example), putting a little too much heat on it will cause it to melt.
But, lets say you're working on a ring that has been sized before, and the goldsmith used Easy solder. You want to use a Hard solder, which is better, but requires so much heat that the Easy solder melts before your Hard solder does. As a result, you end up with the previous goldsmith's work coming apart while you're trying to do your work. Consequently, all too often, we end up having to repair the previous goldsmith's work in addition to doing our job.
As for "stretching" rings:
There are rare circumstances where we will agree to stretch a ring. Generally, stretching can cause all sorts of problems, from making the metal brittle to altering prongs or channels. However, for example, if a wedding band had a decoration all the way around it and it has never been sized, then we will, under certain circumstances, anneal the metal (put it through a softening process) and stretch it.
**A note- Generally, due to the high volume of work we do, we need to schedule our jobs. In other words, you need to leave it with us for a few days. Having said that, we understand there are times when people need it done NOW. Consequently, we do provide an "express" service at an additional charge. Just let us know up front, please.