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Hoover & Strong does have a high white gold alloy in 14K (14H) and 18K (18H) white gold, called Brilliant White gold (please note, available in casting grain only). However, jewelers need to be aware that all of these products contain a high amount of NICKEL. These alloys may be slightly more hypoallergenic than its predecessors, but these alloys still have the same problems of all high nickel alloys. They are harder to work, harder to cast and more prone to prong failure. Hoover & Strong promotes 950 palladium as a better option - TruPd is pure, white, precious and strong. 950 palladium is naturally white, needs no Rhodium, is malleable and is similar in cost to 14K gold.
Hoover & Strong's Brilliant White gold offers jewelers a high white color. However, because of the high nickel content it is not suitable for rolling. Hoover & Strong recommends their 14K & 18K palladium white gold or 950 palladium for rolling, because of its malleability.
WCA is a casting alloy to make 18k white gold; it is very difficult to work with because of the high nickel content. However, it can be rolled with effort and care. This is the reason that we suggest that you order Hoover & Strong's 18k white fabricated material.
Both of our palladium white gold alloys have 13% palladium included.
Hoover & Strong offers two 14K yellow gold alloys; 14K Yellow and 14K Royal. Some customers see these alloys as more toward the pinkish hue and greenish hue respectively. These alloys expand our precious metal offerings to our customer base to meet their design needs.
Green gold color is dependent on both the gold and silver content to achieve its maximum green color. Therefore, you cannot get as green of a color in 14K as with 18K. Hoover & Strong's 18k green is as green as you can get, unless you alloy 75% gold and 25% silver. However, the 75/25 alloy too malleable or soft for most jewelry use. If you add more silver to our 14k green alloy it will not get greener, it gets paler.
Green gold color is dependent on both the gold and silver content to achieve its maximum green color. Therefore, you cannot get as green of a color in 14K as with 18K. Hoover & Strong's 18k green is as green as you can get, unless you alloy 75% gold and 25% silver. However, the 75/25 alloy too malleable or soft for most jewelry use. If you add more silver to our 14k green alloy it will not get greener, it gets paler.
Yes, Iridium is extremely hard. Customers have asked if they could make a ring out of iridium. It would be very difficult to cast a ring in iridium (although Hoover & Strong has done it) and it will crack very easily.
585 platinum is a platinum alloy that has 58.5% pure platinum. Some jewelry manufactures were trying to produce and market a 14K platinum alloy to lower the cost. Hoover does not supply or sell this product, and does not know the formula of this material.
Some casters use Cobalt in their platinum to make the alloy easier to melt and cast. However, Cobalt is magnetic and will cause a slight oxidation when the metal is melted and annealed.
It depends on the environment. If you live in Palm Springs or Phoenix for instance, it may last up to a year without tarnishing. But if you live in New Orleans or somewhere that is humid or has more pollution, it will not hold up that long.
Technically yes, but for jewelry purposes it is not economically practical. Hoover & Strong will not guarantee better than .999 pure silver.
.935 Argentium Sterling contains germanium which leads to embrittlement, making the alloy more difficult to work with, cast and fabricate. TruSilver contains no Germanium thereby alleviating these issues and making the alloy easier for the designer to fabricate.
Working with Tru-Silver and Argentium Silver? Both TruSilver and Argentium silver are tarnish resistant alloys of sterling silver and can be hallmarked as such. Both alloys have the same color because of high silver content. Both alloys can blackened using liver of sulphur however the process takes quite a bit longer and results achieved are not as dark as standard sterling. Being of Sterling quality most applications resemble working with standard Sterling silver.
The differences are below:
Tru-silver +/- Ease of fabrication, superior tarnish resistance 4-5 times better than that of traditional sterling. Good solderability any silver solder can be used, superior surface finish due to tighter grain structure, metal recyclability is 50% higher. Does not fuse and is not firescale resistant.
Argentium silver+/- Can be used to fuse, is firescale resistant, can become brittle after heating, lower soldering temps. Use H&S hard, medium or easy Argentium solders only.
Many jewelers feel that dealing with fire scale is the most difficult part of working with sterling silver. Argentium is tarnish resistant and heat treatable.
Argentium Sterling silver is a tarnish resistant sterling silver. Many jewelers feel that dealing with fire scale is the most difficult part of working with sterling silver. Argentium is tarnish resistant and heat treatable.
Sterling silver is 92.5% silver and 7.5% copper. Tru-silver and Argentium Silver are 92.5% silver with less copper and other metals in the alloy to resist oxidation.
Nickel white gold alloys can be difficult to cast for several reasons. Firstly, nickel can oxidize, and this is very difficult to reduce, meaning the oxide gets included in the casting, making it brittle. Secondly, nickel white gold alloys react with investment, generating from it a gas which can make the surface of the casting rough and porous. Careful monitoring of melt protection and casting temperatures is needed to avoid these problems.
White gold contains gold, copper, nickel and zinc. Most alloys use nickel as the whitening agent. These metals are whiter than palladium white gold, but are not as malleable. Nickel white gold is difficult to forge, and will crack if the metal is not annealed long enough or if not annealed at a high enough temperature. To anneal, the metal should be heated to a cherry red (1500 f) and then allowed to air cool. White gold should not be quenched. White gold is hard, but annealing too frequently can cause cracks. Hoover & Strong offers 14k palladium white and 18k palladium white which are much more malleable.
Once a piece of metal is annealed re-annealing it will not make it noticeably softer. The piece must be forged or work hardened before it can be affectively annealed again. 18k white is just a very difficult metal to work with due to the nickel content and difficult to over anneal. 18k palladium/white gold and 950 palladium are much more malleable.
Palladium white gold may be annealed similar to traditional white gold with a torch or furnace. Heat metal to a cherry red color, 1400 - 1500F, for 30 seconds and let the metal air cool, or quench the 14K alloy to achieve maximum softness (quenching has little to no affect in 18K).
"D" or Deox alloys usually will have silicon in them to help casters reduce oxidation and porosity. However, these deoxidizers will generally increase the metals temper, making them slightly harder. If the metal is over-heated, this will make metal harder to the point of brittleness. Remember Hoover & Strong does custom casting and specializes in unusual colors and metals.
Royal yellow and green gold alloys have more silver that yellow gold. If these alloys are cast at too high or too low of temperatures they will have more porosity. First decide which type of porosity is on your castings. If the porosity is sinkage porosity, raise your casting temperatures by 25 degree Fahrenheit until the problem is resolved. If the porosity is due to over heating the metal, lower your casting temperature by 25 degrees Fahrenheit until the problem is resolved. Remember Hoover & Strong does custom casting and specializes in unusual colors and metals.
The black coloring is oxidation. The copper in pink gold will give you problems if you cast the piece the same way as yellow gold. With pink, the addition of copper causes the melt-flow range to be expanded, allowing the melt to improperly solidify while in this range. Increase the number of sprues and thoroughly heat the metal. It is critical to use a small amount of flux and a deoxidizing flame to protect this alloy. Remember Hoover & Strong does custom casting and specializes in unusual colors and metals.
The Hoover & Strong Product catalog offers melt, flask & cast temperatures, Vickers hardness, and annealing temperatures & techniques. Pink gold anneals similar to yellow gold. Heat the metal to cherry red (1400 f) and then quench (for maximum softness) or let the metal air cool.
Yes, but please note that there is a subtle difference in the color, we recommend that you use our 95% platinum/5% ruthenium sizing wire that is now available. If the subtle color difference is acceptable, you can use the 90%/10% solution. Finally, the aforementioned suggestion assumes that the ring being sized is marked at 900. If the ring is marked at 950, Hoover and Strong recommends using 95%/5% to stay within hallmarking regulations.
Annealing can be done using a hand held torch. We recommend oxygen/natural gas. Cleanliness at this point is very important. Use only a brick designated for platinum annealing. Minute quantities of lead, aluminum, steel, gold and silver should be kept away from the work to avoid contamination. Both Lead and silicon in particular will dissolve in platinum making it brittle and unworkable. Use a bright blue oxidizing flame in order to properly anneal. Softening occurs rapidly at 1800F or when the metal is bright orange in color. Once the temperature is reached annealing will occur rapidly. An average ring will require heating for 30 seconds. A 1" sq sheet 18ga will require 1 minute. Air cool or quench.
The trick to annealing is reaching the proper temperature; the most common fault is that you will not heat the metal hot enough to soften it. Once the temperature is reached, annealing will occur rapidly. An average ring will only require heating for approximately 30 seconds. A good guide is a 1" square by 18 gauge sheet will require 60 seconds, increase or decrease the time according to the size of the piece. Platinum can be air cooled or quenched in water after annealing.
The Hoover catalog recommends sodium bisulfate as a pickling agent for Platinum however these two acids will remove oxidation.
Platinum is very malleable and can be reduced, without annealing, further than gold. Platinum can easily be reduced at least 50% in thickness until annealing is needed. Rolling platinum can be done very easily with little stress to your rolling mill. If you begin with a thickness of .15", you can roll to .030" without annealing. The metal will roll out easily, but will be hardened enough in the process to get nice sharp pieces when blanking. However, if the metal is not going to be worked after rolling, anneal at .050" before rolling to .030".
950 palladium may be annealed with a torch or furnace. Heat metal to a cherry red color, 1500-1550F, for 30 seconds and let the metal air cool.
Our 18K Palladium White is a Grade 1 White alloy that does not require rhodium plating. However, our customer's personal preference sometimes requests us to add rhodium plating to finished jewelry for a rhodium whiteness effect.
When doing ring casting, cast might have been too cold or quenched too fast casting temperature recommended is approximately 1850F. When working with Deox Silver, the castings must be air cooled for 15 - 20 minutes (not quench) before dropping into the pickle. If the castings are quenched immediately the casting will crack, or be brittle.
Sterling silver can be hardened by first annealing and then heat treating the metal. Anneal at 1200°F and quench. Place in furnace preheated to 600°F and heat soak the silver for one hour.
Most alloys can be heat treated to some extent. See heat treating instructions in technical section to learn more. Silver offers the best results. 18k yellow and 18k green are the least (because of ratio of silver to copper). Hoover & Strong offers 14k yellow and 18k yellow spring gold alloys when the material needs to be harder.
It depends on the environment. If you live in Palm Springs or Phoenix for instance, it may last up to a year without tarnishing. But if you live in New Orleans or somewhere that is humid or has more pollution, it will not hold up that long.
"D" or Deox alloys usually will have silicon in them to help casters reduce oxidation and porosity. However, these deoxidizers will generally increase the metals temper, making them slightly harder. If the metal is over-heated, this will make metal harder to the point of brittleness. Remember Hoover & Strong does custom casting and specializes in unusual colors and metals.
When doing ring casting, cast might have been too cold or quenched too fast casting temperature recommended is approximately 1850F. When working with Deox Silver, the castings must be air cooled for 15 - 20 minutes (not quench) before dropping into the pickle. If the castings are quenched immediately the casting will crack, or be brittle.
"D" or Deox alloys usually will have silicon in them to help casters reduce oxidation and porosity. However, these deoxidizers will generally make the alloy more brittle and therefore more difficult to work with and fabricate. With experience, these alloys can be fabricated, however they are formulated to enhance casting, not for sheet or wire fabrication.
Royal yellow and green gold alloys have more silver that yellow gold. If these alloys are cast at too high or too low of temperatures they will have more porosity. First decide which type of porosity is on your castings. If the porosity is sinkage porosity, raise your casting temperatures by 25 degree Fahrenheit until the problem is resolved. If the porosity is due to over heating the metal, lower your casting temperature by 25 degrees Fahrenheit until the problem is resolved. Remember Hoover & Strong does custom casting and specializes in unusual colors and metals.
The black coloring is oxidation. The copper in pink gold will give you problems if you cast the piece the same way as yellow gold. With pink, the addition of copper causes the melt-flow range to be expanded, allowing the melt to improperly solidify while in this range. Increase the number of sprues and thoroughly heat the metal. It is critical to use a small amount of flux and a deoxidizing flame to protect this alloy. Remember Hoover & Strong does custom casting and specializes in unusual colors and metals.
According to the gold counsel, you should use at least 70% new gold.
Most fire scale is removed by pickling in a sodium bisulfate based solution. A common pickle pot used to hold and heat the solution is a crock pot. The pickle solution works best at about 180F or 80C. Oxides that are harder to remove, such as those generated with nickel white gold alloys, can be removed by using 5% nitric acid. Fire scale is best removed from silver alloys by using a 10% sulfuric acid solution.
We do not recommend adding more silicon to the sterling "d" casting. Without proper metallurgical or alloy experience you can quickly ruin the alloy. A little bit of silicon goes a long way and too much silicon will produce a brittle alloy. Remember Hoover does custom casting and specializes in unusual colors and metals.
A sprue is used to cast a piece of jewelry. The sprue provides a channel through which molten metal is fed into the mold. The sprue attaches the wax piece of jewelry to the tree stem. You should always sprue to the thickest part of your casting. The sprue should be at least 1.25X as thick as the thickest part of the casting.
A button is used to cast a piece of jewelry. The button is a cylindrical piece of metal used to push the molten metal through the sprue. It is designed to solidify last so that there is correct feeding to the sprue and therefore the castings take place.
Investment is used to cast a piece of jewelry. Investment is gypsum, which is a plaster-like material that is formulated to withstand the necessary temperatures, and gives a good surface. The investment is poured into a flask around the wax tree. The investment solidifies and the wax is burned out, leaving a cavity in which the metal is poured into - producing a duplication of the wax tree in metal.
Oxides that are harder to remove, such as those generated with nickel white gold alloys, can be removed by using 5% nitric acid. Fire scale is best removed form silver alloys by using a 10% sulfuric acid. If you do not have 10% sulfuric acid, but a higher strength, always add the acid to a larger volume of water when diluting.
Red golds are popular now and obtaining a red easy solder is a common problem. It is just not possible to formulate. Solders are formulated to melt before the gold that you are soldering. Typical metals used to lower temperature are zinc or cadmium. The high copper content and the high melt temperature for both gold (1945°) and copper (1981°) prevents the result of a lower melt temp solder. If the appropriate amount of zinc and/or cadmium is added, the resulting solder turns yellow, not red. Our recommendation for a lower melt temp solder is to use 14KY Medium.
Hoover and Strong does not offer these solders, however, we do offer a 14K Green Hard Solder that has a flow temp of 1,450 degrees. Our 14K Green metal has a melt point at 1,595, almost 150 degrees higher than the solder flow point. This spread between flow and melt makes the 14K Green Hard Solder a reasonable solution for the vast majority of designer's applications.
14K Yellow Easy Plumb solder is true 14K solder while the 14 Yellow Easy Repair solder is sub karat, hence the reason for omission of the "K" in the title used for Easy Repair Solder.
If it is a plumb gold solder, then yes, it has the same gold content as the karat alloy, regardless of the grade (hard, medium, and easy). All repair solders are sub-karat. Silver solders have less silver content as sterling. None of the platinum solders are plumb but they have to have 95% precious metals.
Platinum has a high melting temperature (3265°F) and is a poor heat conductor (gold is a great heat conductor). These two factors cause jewelers to have cold solder joints. Cold solder joints happen when the solder flows, but the joint was not heated enough to cause to joint to fuse together. When soldering platinum, heat the joint quickly using a hot flame directly on the joint and solder.
Always use the solder to match the karat and color with the lowest melt point. In this case, 14k yellow (1500°F) has the lower melting point than 14K green (1595°F), so use 14k yellow solder.
No, none of our solders or alloys contain lead.
You must make sure that you use a hot flame directly on the solder and joint. Platinum is a poor heat conductor so the joint and solder must be directly heated. It's OK if the platinum turns red, it should to have the joint fuse properly. Remember, to melt platinum to molten you must get to white hot.
No. Solders are designed to melt at a lower temperature than alloyed metals, so that the metal does not melt. Solder allows the jewelers to assemble jewelry without melting the pieces together.
Brazing and soldering is accomplished using the same process by the user. The difference is the temperature that the material (solder or braze) liquefies. Below 840 degrees Fahrenheit, the process is considered soldering while above this threshold, the same process is considered brazing.
You use the solder that will melt before the metal of the lowest melting temperature. In this case, 18k yellow gold melts at 1580°F and platinum at 3270°F, use 18k plumb gold solder at 1525°F.
Hoover and Strong recommends to our customers to use the parent metal whenever laser welding Platinum. We offer a large selection of laser wire in various alloys. Go to the catalogue or website to see the selection. However, if solder is desired, use 1700 Platinum Solder.
Best results are achieved using platinum step solders. Hoover offers 1000 to 1700 platinum step solders.
Hoover and Strong provides coins and bullions to our customers as a value added service. We believe that our pricing is competitive with the overall market when our customers are purchasing these items for longer term investing. Shorter term investing in Hoover and Strong coins and bullions is not common.
Yes, however the bullions are hand poured leaving the surface formed and not perfectly flat. Each bullion is individualistic.
Yes, we will cut up to 5 pieces or 2' for free. Multiple cut pieces of straightened round wire cost $.62/ft cutting charge. If ordering coiled round wire, we cannot guarantee exact cut lengths.
Hoover uses regular temper sterling, which is 1 die hard, or annealed 1 die before the final diameter.
We recommend that for this application, you order the wire dead soft. This makes it easier to work with and you will put temper back into it when twisting.
Yes, Hoover offers numerous sizes of triangle wire, configured straight, in up to 1 foot pieces. Hoover will manufacture coiled shaped wire over 2 feet. There is a 1 foot minimum for silver.
No. The sterling sheet is completely hardened.
Yes. We can cut sizes of gold, platinum, and palladium up to 6 inches wide. We can cut silver sheet up to 12 inches wide.
Hoover can roll sheet down to .008" (32ga) thick, however, minimums do apply for this fine a measurement of gold.
Work hardening a sheet or wire does make it springy. However, if the material is going to be annealed or soldered, the metal will become soft. The advantage of spring gold is that it can be heat treated to make it hard again.
No. We will certify fine silver only.
We can only coil those sizes 2.5mm and smaller. The larger sizes are cut from sheet and cannot be coiled.
Yes - we can make it for a special mfg charge of $19.50 per size. Because 14K royal sizing wire is special order there is an additional delivery time of approximately 5 days, depending on the time of year. 18K royal sizing wire is a stock item.
Channel wire is commonly used for coin mountings.
Hoover and Strong provides inside and outside diameters of the tubing in the catalog. Compare the outside diameter of the tubing with the inside diameter of the closest size to see which size will be the closest.
Tubing can be special ordered. There is a 100 dwt minimum. Tubing can be made in lengths up to 4 feet. Special order tubing will cost approximately 25% more than standard tubing. TSL 1.5mm only available in 14KY (catalog item)
The most important part of removing mercury from gold is to do it as soon as possible after the gold is contaminated. In a short period of time the mercury will absorb or bond with the gold, making removal difficult. Use a 50% nitric acid and 50% water solution to dissolve the mercury. Do not leave the gold in the solution too long as it will start to dissolve the gold. Another option is to heat the article to vaporize the mercury off the gold, use proper ventilation. Be careful not to melt the gold.
The most important part of getting lead off of gold is doing it as soon as possible after the gold is contaminated. In time the lead will absorb or bond with the gold, making removal difficult. Use 40-50% nitric acid with water to dissolve the lead. The higher the acid concentration, the quicker the gold will discolor. DO NOT HEAT THE LEAD - when heated the lead will amalgamate into the gold.
We recommend that clean scrap is sent insured and securely packaged. In order to process your payment most efficiently, we recommend utilizing our payment processing form on our website or you may contact us directly at 800-759-9997. Our payment processing form provides options for your payment and maintains record keeping.
Absolutely. The proceeds you receive from refining may be used to purchase new manufacturing materials or may be credited to an existing balance. Clients that utilize both services, manufacturing and refining, often receive additional discounts for loyalty business.
Contrary to popular belief, the value of most gold coins is in the intrinsic gold value only. To estimate the value of a coin, take the weight × the metal market price. Most dealers will buy fine gold at 1% - 5% under market price, depending on quantity and demand. Unless the coin is an antique, it will likely not have a collectible value above the metal price.
We only accept precious metal scrap. This includes white gold, yellow gold, pink, red and green gold, platinum, palladium and silver. Examples are old jewelry including class rings, fashion and engagement rings, wedding bands, necklaces, chains, and any type of sterling silver from rings to silverware.
We have thousands of ring options on our website, including several options for ring blanks. They can order Seamless Ring Blanks (WRB) in 14K, 18K, 22K, 950 palladium, 950 platinum in yellow, white, red and green from 2mm - 10mm. Hoover also offers undrilled Azure® bands (AZU) in multiple stone and finger sizes.
Yes. Since this is an undrilled band, a customer can make as many holes as the band's azures. In a size 6, you can have up to 22 holes.
We offer a wide range of stone setting services, with expertise in all types of setting styles. From a simple four prong to the most difficult Micro-pave, our years of experience and dedication are unparalleled. Our trained setters are ready to help with all your stone setting needs, including prong, bezel, channel, burnish, pave and more. We can set and finish your jewelry with your stones or with ours. For additional information, call our customer service department at 1-800-759-9997.
We size all of our bands to the leading edge for consistency and ease of communication.
This is a trademark of Hoover & Strong's bands. The rings are similar to comfort fit bands. They have a radius the inside of the band so that less metal is against the finger, giving additional comfort to the ring.
Hoover makes their 18K bands in18k palladium white gold, which allows easy bead setting. Our AZU02, 04, 07 and 12 complete azure/undrilled band is commonly bead set.
Open holes with the appropriate setting bur. Set the middle stone first. When setting the outside stones, center prongs are shared. Cut a notch inside of the center prongs. Cut seat in outside prongs. Fold over the stone to lock it into the notch in the center prongs.
Our TruSeat settings and bands save jewelers up to 80% labor when setting stones. These are products with pre-cut seats in settings and channeled anniversary bands, allowing jewelers to set stones quickly. TruSeat® settings accomodate 90% of all diamonds and shapes. Less time is required by skilled jewelers and less skill in needed to produce consistent high quality results.
Yes, our most popular selection is the six prong SHZK63/S616 and the four prong princess solitaire is the SHZK43/PPR46. The definition of a Tiffany setting, from the Jeweler Dictionary: a six-prong setting generally round in shape and flaring out from the base to the top, having long slender prongs that hold the stone. Sometimes applied to four-prong settings as well.
A simple way to clean dirt from under a stone is to use a toothbrush with soap and water. Do not be too aggressive with the toothbrush as you don't want to loosen the prongs of the ring. An ultrasonic cleaner is less aggressive and easy to use. The ultrasonic uses vibration and a cleaning solution to clean behind the stone.
Hoover's finished solitaires have a 4-5% metal loss. Solitaires sent to jewelry contractors for finishing can have up to 10% loss if split lapping is used to finish their solitaires, which takes off more gold.