How to Set a Round Stone in a 4 Prong Setting

How to Set a Round Stone in a 4 Prong Setting

On the last post, I soldered a 4 prong head onto a shank I made and I mentioned…. ok, I promised I would demonstrate how to set the 2mm stone in a 4 prong setting. In past blog entries I have set stones in shared prong settings, flush settings or gypsy settings, channel settings, bezel settings, and “V” prong settings, but I have never showed how to set the most common of all settings, the basic 4 prong setting in a die struck setting, so kick back, grab a cup of coffee, and enjoy.

I do a little prep work to the head before I begin setting the stone. When I soldered the head into place, there is a little fire scale to the inside of the head. I pre-polished the shank and the outside of the prongs with a 3M Brushes and a Brass Brush in my Foredom. I like to clean up and polish the inside of the setting before the stone is set, for once the stone is set, it is difficult if not impossible to shine the inside of the setting. To polish the inside of the setting, I use a small piece of cotton wrapped around a 0.7mm Tapered Cylinder Bur. A small ball bur will also work. I like to use Natural Cotton, which I usually get out of an aspirin bottle, as opposed to synthetic cotton because it seems to me that the natural cotton holds onto the polishing compound better, but either will work. I spin the cotton onto the bur into a cone shape and add Red Rouge to the “bullet” shaped cotton. I insert this into the inside of the setting and polish.

After the inside is polished, it is time to notch or cut the seats into the prongs. As a rule of thumb, I like to cut the seat about 1/3 the way down the prong, from the top, and cut about 1/3 the way into the prongs. Here, I use a sharp set of dividers to mark the inside of the prong at the same level. I scribe a line as a guide to start cutting. In this instance, the stone I am setting is 2mm, I am using a 1.5mm Hart Setting Bur. The girdle (or side) of this stone is a little thicker than normal, so I cut the seat at an angle to match the stone. When setting stones, always try to match the shape of the girdle with the shape of the cut into the prong.

 

Next, after you have cut the seats into the prongs, place the stone into the setting and visually check to make sure each prong matches the stone shape and make sure the stone is level. If it is not, adjust the cuts in the prongs at a bit and check again until you are satisfied. Once you are happy with the way the stone sits in the prongs, gently close the prongs with a pair of Needle Nose Pliers to hold the stone in place. Again, check the stone to make sure it is sitting the way you want it to. After you have the prongs closed onto the stone, it is time to tighten the stone. Using the same pliers, gently pull the top of the prong over the stone by placing the pliers at an angle, using the prong on the opposite side to support the pliers and pull the top of the prong down onto the stone. Do this to all 4 prongs, making sure the prongs are “square” or evenly spaced from one another. Check to make sure the stone is tight by grabbing the stone with your Tweezers and seeing if the stone spins.

Once the stone is set and tightened, I like to file the prongs down just a bit to make sure the prongs are even and all the same height. I use a #4 Barrette Needle File to do this. Next I use a small 1.0mm Cup Bur to round and finish the top of the prongs. The prongs measure about 0.6mm in thickness and a 1.0mm cup bur seems to be about the right size. You want to use a cup bur that just fits over the whole prong and does not “ride” on the stone. Make sure you only use this just enough to round the prong and not reduce the size of the prong too much. You want some prong on top of the stone so it won’t wear down too quickly.

Lastly, after the stone is tightened, and the tops of the prongs are finished to your liking, it is time to polish the tops of the prongs. I like to use a Medium Hard Felt Wheel with Red Rouge on it. Again, you do not want to get carried away and polish off the tops of the prongs, but just enough to give them a good shine.

I know this stone setting is rather small at 2mm, but the same process will work for any size stones. If you are new to setting stones, I would suggest starting with larger stones to get used to the process.

I hope this helps to explain and simplify the basic 4 prong setting. Mastering this process will go a long way in stepping up your stone setting program and help you to design more pieces with stones, opening up a whole new world and making you more confident in all types of setting.

Thank you as always for stopping by and following along on this journey. I hope you are experimenting with some of the techniques I share. Be sure to sign up to get these tips emailed to you, or send in comments or questions either by commenting here, emailing me at doug@jewelrymonk.com or send me a voicemail. I read and check them all.

Now, get out there and Dazzle the World!

Doug

”The soothing tongue is a tree of life, but a perverse tongue crushes the spirit.”