Gluing undrilled pearls

[ocean]

Hi all,
I know that most pearls are drilled before being glued onto the mountings. So just wondering if it is ok if the undrilled pearls are glued to the rings or pandants? How stable is it? will it actually fall off easily? anyone tried gluing undrilled pearls onto the gold jewelleries? I was recommended to use this Devcon 5 Miniute Epoxy glue. Just wanna find out if there's a big difference between gluing drilled and undrilled pearls .Thanks people!
http://www.eastoceanpearls.com

 

[Zeide Erskine]

Hi Darren,

Gluing undrilled pearls is not recommended. You can prong set undrilled pearls but the available contact surface would not be large enough for pearl and setting staying put long-term.

Zeide

 

[preswine]

Hi Darren,

Gluing undrilled pearls is not recommended. You can prong set undrilled pearls but the available contact surface would not be large enough for pearl and setting staying put long-term.

Zeide

Why isn't it recommended? I was speaking to a jeweler about how to mount a pearl into a ring without drilling it (you know the one Zeide) and they suggested both a prong set AND glue. They also claimed that both gluing and ungluing (for ring resizing) would not harm the pearl in any way.

After reading the ungluing thread (microwave oven??!), I'm a little skeptical about the claim that ungluing is completely noninvasive to the pearl.

 

[Zeide Erskine]

Hi Preswine,

If your pearl is both prong-set and glued (without drillhole) the latter will only stabilize the pearl in its setting, i.e. prevent it from spinning in the mounting. The great difficulties of ungluing a pearl particularly refer to epoxy-glued drilled pearls. If you want to mount an undrilled pearl, prongs and glue will be the safest way.

Zeide

 

[Caitlin]

Has anyone tried Rhino glue? http://www.rhinoglue.com/order.html
Notice Rhino glue makes a debonder product. The product also works to soften epoxy and other such glues.

I think glue without drilling or prongs would easily break off- along with layers of nacre, if stressed.

 

[Zeide Erskine]

Hi Caitlin,

I think it depends on the glue you are using. You wouldn't use as strong a glue for stabilizing an otherwise prong-set undrilled pearl in a ring mounting as you would for a drilled one to secure earring studs. If you restrict yourself to a little dab of Hypo Cement, your nacre will be safe and the pearl stays put. Going for Vigor or Crazy Glue would be a touch of overkill for stabilizing a prong set pearl but perfectly appropriate for earring studs on drilled pearls considering the mechanical stress the joint would have to withstand.

Zeide

 

[purepearls]

I agree with Zeide. I recommend both the glue and prongs as well. For rings, I do feel a stronger glue is necessary because if you hit your hand on something or if you get the ring caught in your pocket, you don't want the glue to be weak because you could end up losing the pearl.

 

[Taylor]

If the pearl is prong set, is it usually drilled as well? If not drilled can it be turned over if the top surface becomes dull or scuffed with time?

 

[gemologist]

Gluing

Gluing

I have had mixed results with gluing, I have found it to be very effective in lower quality or more boroque shapes, and insufficient in round, good quality pearls. If you have a larger pearl that is half-drilled, it is possible to either enlarge the drill hole or use the post with epoxy.

However, it is possible, especially with irradiated treated and heatment annealed black pearls to cause permanent damage with the epoxy, however, with the freshwater loose pearls I sell, I have never seen damage from glue, even when the glue does not hold as well as hoped.

 

[gemologist]

I have also heard from one of my top buyers that rhino glue is the top glue for undrilled pearls, and she has bought literally pounds of pearls from me.

 

[Pearl Dreams]

Hi gemologist,

I know there is a way for vendors to properly identify themselves and place links to their commercial website as part of their signatures. Caitlin is the Administrator and can help you out with that information. She'll probably be along soon, or you can send her a private message.

 

[Caitlin]

I already sent a PM with the instructions yesterday

 

[julianner]

I have also heard from one of my top buyers from my website undrilledpearls(dot)net, that rhino glue is the top glue for undrilled pearls, and she has bought literally pounds of pearls from me.

I've just tried that URL and it doesn't seem to work...?

 

[KAC]

Hey Julianne,

I just checked it, seems to be working for me:

http://www.rhinoglue.com/order.html

 

[J Marcus]

My 35+ years of experience in this area says that there are more factors to this than one might think. To start with, on the subject of setting pearls with glue: Is this a design where the pearl will be standing proud or will it be cemented into a recess? How much of a recess? What is the size of the pearl? If it is going to be standing up out of a recess more than half way, then don't do it. It will get knocked, broken loose and fall out at some point. As far as glue goes--there is glue and then there is glue. . . Many epoxies break down and loose their strength over time. The ones that seem to hold up the longest are the ones with the longest curing times. I've seen fast setting epoxies degrade in a couple of years. When epoxies are new, then it is almost impossible to loosen them with anything but heat. Even "Attack" usually won't do it. I find the cyanoacrylate glues best but most of them are brittle and will break. There is one called "Flexi-Cure" by the company that distributes "Maxi-Cure" and "Insta-Cure" that seems to be less brittle but it's fairly new. These are some of the best of this type--always use a premium glue. Try hobby shops. Grizzly sells it too.

Prongs--more factors: How heavy are they? Thin ones aren't usually strong enough for a ball shaped gem. The gentle curve of the pearl acts as a wedge. They must reach past the center point of the circumference for them to have any holding effect at all and if they are long enough to really do the job they start to hide/overpower the pearl. Also, if the prongs are sturdy enough to do a good job then you will probably scratch the pearl when setting it. Karat golds are harder than pearls. Glue may help (Insta-Cure) but nothing other than hard solders hold well to gold or silver. Roughen the glued surface--it helps some. How large is the pearl? The larger it is, the less well prongs or glue will hold it. (leverage)

The best ways are post and glue and fully drilled pearls with a wire runnng through to secure it. (Not good for many designs.) Avoid cast pearl posts like the plague. They usually have a crystalline structure and are subject to breakage. Silver is rather weak compared to gold and should have a thicker prong. (...and a wider hole.) Smooth prongs just don't cut it!! Use a file or jewelers sawblade to roughen the prong. You must have a physical bond--don't count on a molecular bond with precious metals. Again--use a cyanoacrylate glue. With epoxy, for about the first six months or so don't count on unbonding it with anything but heat. (How brave are you?) After a couple of years or so, many epoxies start to deteriorate. Clean out the hole in the pearl first and make sure that you get the glue all the way down in it. Remove with "Attack."

Good luck!

Marc
http://www.flyrodjewelry.com/home.html

 

[julianner]

Thanks for the rhinoglue link. I was actually referring to the other link 'undrilled pearls', but that's OK, I just checked it again and it goes off to a classifieds page somewhere over your side of the planet.

And Marc, thank you so much for your great post on gluing and posts etc. That's the most detailed info I've read on the subject and very, very useful. Much appreciated.

 

[J Marcus]

Julianner: You're quite welcome. One thing to keep in mind is that in almost all cases (99.9%) a physical/mechanical attachment is stronger than one done with glue. The exception to this is the Post and glue method and, done right, it is more of a physical lock than a chemical bond and it should be as strong as the post.

Marc
http://www.flyrodjewelry.com/home.html