Re-Tipped Prongs and Porosity on Your Engagement Ring


What is Porosity? In the simplest of terms, porosity is how holey a material is. No – not “holy” in a religious sense, but “holey,” as in “full of holes.”

Materials such as pumice stone and concrete tend to be very porous, while materials like glass and hard plastic are relatively non-porous. All materials have some degree of porosity, even if the pores/holes are not visible to the naked eye.

When it comes to jewelry, however, those little holes can become a big problem.

Porosity Bubbles, Gas, and Microscopic Shenanigans

ring porosity problem

These Dimples Are the Result of A Porosity Problem on a snake ring

The metals used in jewelry tend to be relatively non-porous and contain only microscopic holes. These microscopic holes, however, can become not-so-microscopic when gas is absorbed into the metal (typically during a heating process) and then released incompletely from it as the metal cools.

Porosity in cast ring

Porosity in Cast Gold Ring.

While the small dimples on the surface of a jewelry piece can look ugly, the real danger of porosity comes from the structural damage the bubbles cause as they expand beneath the surface. These bubbles weaken the structure of the ring and can lead to cracks, breaks, and discolorations.

Porosity in jewelry can be like an iceberg. I once went to polish out a little porosity hole. And I polished and polished. And the hole got bigger. As the wheel spun down as I turned it off, I looked at the ring I'd been so excited to set and said, "nope. That design is going back to casting."

Vacuum Casting to Avoid Porosity Problems

This is why jewelry is often cast in a vacuum sealed casting machine, which replaces the oxygen in the chamber with argon gas. Metals -- particularly those used in jewelry -- tend to bond very readily with oxygen. Argon, however, is a very non-reactive gas and will not bond with the metal being cast. While some small amount of oxygen may still remain in the chamber, the vacuum sealed machines are quite efficient, and porosity is rarely a problem during the casting process.

Jewelry Repairs - Why Porosity Rears its Ugly Head

torch with flame for solder

Open Flame Soldering Will Expose Large Sections of Your Jewelry to Intense Heat

Jewelry repairs that are done by hand cannot be done in an oxygen-free atmosphere – that would suffocate your jeweler! Repairs often require pieces of metal to be connected through open flame soldering. The soldering process requires high temperatures, which greatly increase the speed at which oxygen reacts with metals. In other words the hotter the metal gets, the more it pulls in oxygen.

With open flame soldering, it is impossible to only heat the area that is being worked on. Inevitably, surrounding sections of the jewelry will be exposed to high temperatures, causing them to absorb oxygen as they heat and release it as they cool. This is the primary reason for porosity spots on jewelry that has been repaired.

That Ring of Yours Presents a Minefield of Hidden and Unseen Pitfalls for Your Jeweler

Many pieces of jewelry contain elements that are joined together to create a whole piece; a prong setting or a decorative piece might be added after the original jewelry piece has been created. The areas where connections are made during the soldering process are known as "joins."

There are three varieties of solder used to create these joins: soft, medium, and hard. Soft solders use metals with low melting points, while hard solders use metals with high melting points; medium solders, naturally, fall somewhere in the middle.

When repair work is done on jewelry, previous joins can be undone by the heat work of the current repair. This is a source of jeweler nightmares, and care must be taken so that the previous joins are not undone.

Flirting with Porosity - When to Use Soft, Medium, or Hard Solder

Porosity spots on a ring

These Prongs Appear to Have Been Re-tipped with Soft Solder, judging by the High Percentage of Porosity Spots

Soft or medium solders are typically used in jewelry repair so that the joins of previous work are preserved. When soft solder is heated and then cooled, problems with porosity are nearly inevitable. It’s a bit less of a problem with medium and hard solder.

When re-tipping prongs, jewelers sometimes solder pre-made prong tips to the head or base of a ring in order to create a neater finished product. However, if the entire new prong tip is made up of solder (which is more common than you might think), there will probably be visible porosity throughout the remade tip and often an unevenness in size.

If Soft Solder Causes Porosity, Why Use it?


In the Re-Tipped Prong Closest to You, Solder Flowed Unattractively onto the Design Creating a Blobby Look Where Precise Design Would Have Been Prettier

Soft solder is advantageous in many circumstances because of its relatively low melting point. If your jeweler does not want to conduct heat to sensitive gemstones on your ring, soft solder can allow them to work quickly.

If your piece is particularly delicate and composed of many thin elements, soft solder may be your jeweler's only option to avoid damaging your jewelry.

For re-tipping in particular, soft solder is also a cheaper option that can cut costs on an otherwise expensive repair. While the cheaper option will always be enticing, the lowest price re-tipper may not be the one you want working on your ring.

Can my Porosity Damage be Fixed?

After Porosity Repaired on shank of snake ring

After the Repair was Done with Laser Welding to Correct Porosity on the Snake Ring

Yes! But it can be expensive. Porosity damage is often done through the use of laser welding. Because of the cost, laser welding may not be a viable option for everyone.

However, if porosity is really uglifying your jewelry or compromising the integrity of joins that hold expensive diamonds in place, laser welding is a great way to get your jewelry fixed.

This All Sounds Scary - Why Write About It?

Full disclosure -- my husband thought that writing this was a terrible idea and that I’d needlessly freak people out about a fairly normal problem that can happen in casting and repairs. Porosity is not a good thing, but neither is it a disaster. As I've tried to explain in this blog, the main "danger" of porosity is simply that it's unattractive.

The key is that, structurally speaking, it's OK in small amounts. While it's not ideal in terms of looks, I've had clients request multiple expensive, time-consuming repairs simply because they feared for the structural integrity of their jewelry. While I'm happy to work on their jewelry, I first need to make sure they realize that they're spending their money on a cosmetic fix rather than a structural one.

Porosity in Re-tip and Bad Workmanship by a Hack jeweler

Bonus Picture. Notice the Awful Yellow Gold Globby Tip on the White Gold Base. Porosity AND Heinous Workmanship! Photo credit - Jewelers Helping Jewelers

Now that I've responded to hundreds of great questions through my blogs and comments, I wanted to address a less frequently asked question. Not many jewelers talk about this stuff. Who even knew it was called porosity? I love to put my clients and readers in the driver’s seat. I want them to know what porosity is, when it's a problem, and what they can do about it. If they care.

I’d love to know if you’re with my husband and think that I should just take this post down, or if you actually find the information helpful. Please talk back in the comment section below. I love your feedback, questions and opinions!

Your Personal Jeweler,

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About Calla Gold

Calla Gold is a Personal Jeweler and Author who takes pride in working with clients one-on-one to integrate their personal sense of style and taste into custom designed jewelry and repaired jewelry pieces.   Unlike typical Santa Barbara jewelry businesses, Calla Gold has no brick-and-mortar location. Calla Gold comes to you, bringing you the jewelry collection you want to see and collaborating with you to create unique custom jewelry. Calla also works with at-a-distance clients.

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7 years ago

Thank you for the pictures and explaining this phenomena. It’s one of those things, I have seen but other than reflect on the fact that it is ugly and irritating I didn’t know what to do about it.
It will I admit make me feel safer getting repairs knowing why porosity happens and that it can be fixed if it bugs me enough.
Just knowing about it makes me feel better.
Have you had to fix many porosity areas in your career as a jeweler?

Angi Martz
Angi Martz
7 years ago

Tell your husband this is exactly the article I was looking for. Here’s my story I would like your take on it. My husband bought me a very expensive ring 12 years ago from a very reputable well known jeweler. Thankfully he also purchased a warranty that covers loss of diamonds. In the last 12 years I have had at least 6 big diamonds replaced. I lost one last month, took it in to be repaired and I just received a call yesterday from the store telling me “unfortunately the ring has been deemed ‘unrepairable’ due to porosity”. I haven’t… Read more »

Angi Martz
Angi Martz
7 years ago

Calla, From the comments from you and your husband it almost sounds like you’ve seen my ring. It is a high set ring and does get knock around a lot. I do wear it every day because it is so special to me. I will send you pictures but you will have to be patient. It is at the jewelers still and we live in a different town and I won’t be able to go get it for a while. But I will be in touch. In the meantime any thoughts on the liability of the jewelry store? Or would… Read more »

Debra May
Debra May
7 years ago

Hi Calla, I’m glad you posted your article! It was very educational and helped me understand what has been happening to my engagement/wedding band. After 34 years I had the band enlarged and since that time, the band has split after just months of wear (underside where it was enlarged). No stones have been lost. This happened 4 times within the past 2 years and the jeweler is reputable. I have never had a ring behave this way and it was only this time that the jeweler told me about porosity. I don’t wear my ring everyday, but after 36… Read more »

7 years ago

Dear Calla,

I found this article interesting and informative and I love your blog so much that I am slowly working my way through all of your posts. Thank you for educating me.


Nicole Cechini
Nicole Cechini
6 years ago

I just had my engagement ring re pronged and I can see small holes in the prongs that weren’t there before. Should I take it back to the jeweler that fixed it? Is this going to compromise the strength of the prongs?

6 years ago

I have had some repairs done to the setting on my engagement ring in the past. Recently th3 setting broke again and I took it to a jeweller for repairs. He told me that the gold was porous and it was all one piece so I would need to have all of the gold replaced. I have not noticed any cracks in the main parts of the ring before. Is it likely that the whole ring is porous, or could it just be the setting from the repairs?

5 years ago

Hi there,

Your article is super helpful and informative! I just got my newly set engagement ring this week and noticed one tiny hole in the back of the 1.65mm 14k gold band. The rest of the ring looks flawless. Should I be concerned about this tiny hole? I just want to make sure it doesn’t affect the integrity of the band.

Thank you!

Matthew Cooper
Matthew Cooper
4 years ago

I am a jeweler and gemologist in Houston TX. I love this post. Leave it up!!! It is great disclosure to a persistent problem. I do not experience porosity in my repairs or jewelry manufacturing. However, it occurs quite a bit in large manufacturing companies. I have experienced it too many times in my opinion.

Vivian Black
Vivian Black
4 years ago

You made a great point about vacuum casting to get any porosity problems taken care of. My husband and I are looking for an artisanal jewelry manufacturer to help us get some one of a kind pieces. We will keep these tips in mind as we search for a professional that can help us best.