Sizing up a full eternity ring
If you have a fully diamond set eternity ring which is too tight to wear, many jewellers will tell you that resizing the ring is impossible. This might be true. But much depends on the design of your ring.
Two ways to make a full eternity ring larger
Polishing the inner surface
If your full eternity ring has a good depth of precious metal, it might be possible to polish the inside of the ring. Provided this does not affect the diamonds, polishing the inner surface can remove metal, making the fit roomier.
Unsetting and adding a section
This technique is not suitable for channel set full eternity rings but might work in some instances. Each diamond is unset from the full eternity ring. Another section is then added to the ring. This could be plain, or diamond set. The original diamonds are then re-set into the ring. Leaving the diamonds intact during such work would risk breakage of the diamonds.
This is an example of a design where a section could be added after first unsetting the original diamonds. A small plain section was patterned to match the design.
Other ideas for full eternity rings that are the wrong size
Another idea for eternity rings that cannot be worn is to turn them into pendants. Some eternity rings make wonderful diamond pendants as you can see here. Three matching Russian wedding rings, pavé set with diamonds co-exist in a beautiful pendant design.