How do you resize a ring?

July 2, 2005 10:17 AM

Can I resize a ring myself?

I have a bunch of cheap, silver rings that I've accumulated over the years. I don't think it's worth taking them to the jeweler to get them sized, since none of them cost over $30. How is ring resizing done? What tools would I need? I have about 6 rings that need to be embiggened an eighth of an inch or so. Could i just use an abrasive wheel on the dremel as long as I don't take off too much?

posted by electroboy to clothing, beauty, & fashion (5 comments total)

You heat them up and stretch them. Site below, sorry link wouldn't show on preview with html.

http://www.ganoksin.com/borisat/nenam/ring_sizes.htm
posted by lee at 11:09 AM on July 2, 2005

IAAJ (I am a Jeweler), for an eighth of size you could probably pound it larger on a mandrel, with a hide mallet. obviously you need to make sure before hand that there are no cracks in the silver.
posted by CCK at 12:44 PM on July 2, 2005

Eesh, don't use the dremel. The mandrel/hide mallet route is, as CCK points out, sufficient. Silver is pretty darn maleable...it can be stretched without heating (which is essentially what you're doing when tapping up a ring.)

It's also easy for non-jewelers to do. (Put ring on mandrel. Tap at slight angle towards the larger end of the mandrel, going all the way around the shank evenly.)
posted by desuetude at 2:28 PM on July 2, 2005

Harbor Freight has several ring sizers for sale. A mandrel, a stretcher, a setting clamp, sizing gauges, and a pricey expander/reducer if you want to do this professionally. This is not an endorsement as Harbor Freight is cheap chinese stuff, but may be OK for your needs.
posted by 445supermag at 5:07 PM on July 2, 2005

I have done jewelry before, but I haven't been active in years. I think I remember my skills though. I'll do my best to describe the process - but again, it's been a while, but while I was doing it I got pretty good at it. But anyone should feel free to correct me and/or elaborate if they know better.

Note that in all methods of ring sizing, any stones, settings, insets or inlays run the risk of being damaged.

The mandrel method is generally the least traumatic to the ring if done carefully. A smooth hide or even hard rubber/plastic mallet will mar it the least. But you can only size up so far. More skilled jewelers could probably do a whole size on a mandrel, but that'd be a lot of hammering, and you'd be probably be guaranteed to lose/damage any settings, as the whole ring stretches.

If I recall correctly, hammer in firm but not overdone taps on the ring, hammering inwards (kind of sideways-ish) from the smaller end of the mandrel towards the larger end, walking around the ring to distribute your blows as much as possible evenly around the ring. After a rotation or three, pull the ring off the mandrel, flip it around, and repeat.

Done right it shouldn't take too much hammering to size it up a fraction of a size. You might want to buy a cheap but malleable silver ring to practice on, or maybe a couple of them.

For larger upsizing or downsizing - especially for rings with settings - you're probably going to want to cut the ring and resolder it. And that's a lot more complicated.

You'll need the following: A vice, preferably a jeweler's vice, but a hobbyists vice or properly applied woodworker's or other standard vice will do. A jeweler's saw and blades. Jeweler's files, and perhaps a file-handle. Jeweler's pliers (smooth-faced and untoothed, generally finer-gauged like needlepoints). Sandpaper. An acid bath. Silver solder and flux. A torch that's both hot enough yet soft enough. A buffing wheel or tool with appropriate polishing compounds.

That's a pretty complex list, but it's not terrible. Everything is pretty small. You could sign up for a community college jewelry-making class that has a good lab. undoubtedly, it would probably be ultimately cheaper to take it to a pro who has much better tools, but if you buy/obtain/access the tools, you can learn to do it yourself.

Going down a size is generally easier, as simply cutting the ring will remove material, and filing/sanding the gap to be resoldered will remove even more.

To size up, you'll need to actually perform two solderings, which is tricky.

And you'll also need to add appropriate silver stock in an appropriate size and gauge. You can buy ingots and roll it with a mill. You can buy pre-milled plate, or pre-milled wire or barstock appropriate for rings. It's generally not that expensive for pure silverstock, marginally more than what you would pay for raw silver per ounce, depending on the form you buy it and how complex the preparation of it is.

Yes, you can scavenge material from unwanted rings, but getting it to match other rings is even more work.

For all filing, sanding and cutting, use the vise. It greatly assists clean, straight cuts and filing.

You would cut the ring at an appropriate spot, usually 180 degrees from any setting, or at the back if it's a band and you tend to wear it any particular way. Otherwise, just think it through and cut where you like. Cut it as cleanly and as close to square as possible.

With the pliers, gently open the gap wide enough to admit files and sandpaper. File and sandpaper that gap smooth and square on both ends, paying particular care not to round off or taper the ends. The cleaner, flatter and more square these butt up against each other, the cleaner the soldering.

Now you're going to need to figure out how much it needs to be sized up. Measure the finger with ring gauges. Gently reclose the ring and "spring it" shut (more on that later) and measure the cut ring.

Myself, I would guesstimate the difference between the two measurements, and then err slightly on the smaller side. It's easier to slightly expand a ring then to contract it. There's probably some fancy math dealing with circumference and radius that could be applied here, but eyeballing it and thinking it through is usually sufficient if you're mechanically inclined.

Now you'd need to mill, cut, file, and sand a piece of silverstock of the appropriate size, dimensions and even contour to match the ring.

Working on the insert is certainly fiddly work. One technique is to use the pliers as a hand-held vice during the sanding and cutting. A jeweler's vice is a fine instrument, and permits holding even small pieces for cutting and filing.

Another technique is to glue the piece to a stick with some light epoxy, giving the piece a handle to work on one side. You should be able to snap the piece off the epoxy when done with one side, and flip it around to reglue it to work on the other side. I've mostly seen this techniques used for stones, however.

While working on it, and after you've milled your insert-peice, open the ring back up, and test fit the insert.

To "spring" a ring, what you're trying to do is not only close the gap with your pliers, but you're trying to close it in a way that both the butted ends exert force against each other with the spring tension of the metal of the ring. You'll see why you do this later when we get to the soldering.

One way to do this is to close the ring so the butted ends overlap a little, with one end inside, and the other outside. You would then gently pull the inside end up and out so that it doesn't actually permanently bend the metal, but just stays within the springiness and tension range of the metal. The two ends should meet with a bit of tension between the two.

To spring a ring with an insert gets a little trickier. You can close the ring until the gap is just smaller than the insert, and then open it just enough to wedge the insert into the gap. If your insert and butt-ends have been properly shaped and filed, the insert will be held in place by the tension like a keyed piece or puzzle piece.

If it's properly sprung, you can even test-fit the ring on your finger or compare it to a gauge, but chances are pretty good it's not going to be perfectly round yet.

Once you're satisfied with the insert and butted ends of the open ring, clean the parts. (I can't remember if it's just a soap/degreaser and water, and/or acid bath.) Wash your hands, and/or use cleaned tools to handle the ring after cleaning. Any grease, dirt, oils will add impurities and discoloration to the soldering, and weaken the joint.

Spring the parts together. Take it over to your firebrick or fire-proof workspace. Firebrick is recommended because solder doesn't really stick to it, and it helps keep impurities out of the solder and joint. I would imagine that a clean, plain brick or cinderblock could be used in a pinch.

And the reason why you "spring" the parts together is that force not only helps form the metallurgical bonds involved in soldering, but it ensures that the gap in the joints is as small as possible.

Cut a small sliver of the silver solder for each joint to be soldered. Apply the flux to the joints. Saturating the joints should be sufficient. The solder bits should easily tack itself to the flux on the joint, just lay it up against the unsoldered joint over the thin gap(s).

Fire up your torch, and with a medium-soft but hot flame, begin heating the joints from the bottom, "walking" the flame up the joint. Since the two joints are so close together, you might be able to do both at once.

Once the solder and metal get hot enough as you keep "walking" the flame from the bottom to the top, the solder should just sort of magically vanish into the miniscule gap and imperfections of the until-now unsoldered joint.

If you've used too little solder, it'll look like there's still a gap in areas around the joint. If you've used too much, not all of the solder will wick itself into the gap. Choosing between the two scenarios, it's probably easier to deal with a little too much solder, because you can go back and file/sand it down before polishing and finishing the joint.

If you've used just enough solder, it'll look *almost* finished already.

If I recall correctly, drop the still-hot ring into flux remover, which will knock of the flux scales and maybe even loose excess solder, if any. Wash in the acid bath - but not too long, as it'll etch the metal too badly.

Now you can do some sanding and filing to make the joint smooth against the rest of the ring.

After it's roughly finished, if required, expand the ring on the mandrel with the mallet.

After it's been sized, gently filed and sanded down and smoothed against the rest of the contour of the ring, you can finish it off by polishing it on the buffing wheel - taking care to not overheat the ring with the friction (It'll expand the stone settings), or knock any stones out directly with the force of the wheel. Polishing around the settings takes a light hand.

And that's about it. It does take some practice, so it's best to not do it the first time on anything you'd care about losing. You can only take away or add so much metal and do so much soldering before any given piece is unworkable or ruined. Unless you get really skilled at it, and then the only limit is really how much work you want to throw at it.
posted by loquacious at 2:31 AM on July 3, 2005