Start with the amount of sterling silver you want to make. Then multiply by 0.925 to get the amount of 999 fine silver you must add. Multiply by 0.074 to get the amount of copper you need. Use 7.4% and not 7.5 % to ensure that you meet the minimum required 92.5% pure silver in order to stamp it with 925. Your result will be a bit lighter than your intended amount, by about 0.1%. Corrections can be made to make sure you have an amount in excess of your desired amount, but this formula should be used regardless to ensure your silver meets the requirements.
You are correct but I like this formula (Total weight of .999FS) x (7.5/92.5) = weight of copper needed to make sterling. This way we can grab scrap .999FS , weigh it, and then do the math to determine how much copper to add. Now we have the weight of silver and copper to mix and smelt
It doesn't take much to figure out that you want 92 1/2 parts pure silver and 7 1/2 parts of pure copper. Do this with a plan total of 100 g, and it's so easy it's unreal. You can use the same thing on 10 g. Or you can do this with ounces. The formula works just fine you just need to calculate you got a total of 100 parts 7 1/2 of them copper and the other 92 1/2 silver. But you can get good results just doing 93% silver and 7% copper. You easily exceeded all requirements, and you're a little less tarnished on your end product
Technically, if you’re wanting to utilize all that precision in your scale, you should definitely adhere to using 5 significant figures worth of precision in your calculations. Since you’ve weighed out 31.112g of 99.9% purity silver, you can only assume a maximum amount of pure silver at 31.081g. Divide that by the mass proportion of sterling silver at .925 and you get a total alloy mass of 33.601g. You then subtract the 31.112g you weighed out from the total mass of the copper and silver alloy and you get 2.489g of Copper that needs to be added to achieve a perfect 92.500% sterling silver blend. The blend you made is 93.1% silver.
Thankfully, his calculation error was on the conservative side, which is especially good for people with less precise scales or sloppier weighing skills. I wonder if he uses this technically incorrect calculation on purpose for that reason…
Your math is wrong. Adding 2.3g copper to 31.1g of 99.9% silver will result in 93.1% silver by weight. What you want to do instead is: (31.1*0.999/0.925)-31.1=2.488g copper
I believe there is a mistake here... this way you have have calculated the copper weight out of the silver weight instead of the alloy weight combined. The math should be: 31.1÷0.925= 33.6 this is the final sterling weight. Meaning you have to add 2.5g copper and you're done
I have a question about your method. I understand .925 sterling silver to be 92.5% silver and 7.5% other (i.e. copper). By your method, you are not creating that percentage balance in the silver. You are adding 2.3g of copper to an already measured 31.1g of silver, which makes a combined weight of 33.4g. With this new weight, your new percentages are 93.1% silver and 6.9% copper. To correct this, I would suggest that you subtract the 2.3g weight from your 31.1g silver before adding the 2.3g of copper, that way you combined weight still totals at 31.1g and your percentages should be correct. Enjoy your videos!
In this case I would treat this as though you have 100% because you have a scale here with a 3 significant figures. Instead of multiplying 0.075, take your original amount of silver and divide it by 0.925 . Then subtract from that your original amount.
Me alegra que lo hayas mencionado. Es como si dijera que a 100 gramos de plata pura se deben agregar 7.5 gramos, lo cual daría 107.5 gramos perdiendo la proporción. Lo correcto sería 92.5 gramos de plata y 7.5 de cobre.
That arithmetic is wrong. 31.104g = 1 troy ounce. If you add 2.3g to 31.104g, like you did in this videos, you get 33.404g. That 33.404g alloy of silver and copper contains 6.8% copper and 93.2% silver. Sterling silver is 92.5% silver by weight.
*THIS IS ACTUALLY INCORRECT* using your numbers 31.1g silver requires 2.3014g non-silver. If you add these weights together you have a final product weighing 33.4014g. For a final product of 33.4014g to be 92.5% pure it needs to contain only 30.89g grams of silver (33.4014 x 0.925 = 30.89), whereas you used 31.1g of .999 pure silver (31.0689g pure silver) You would also want 7.5% of your final product (33.4014g) to be non-silver. Meaning you would want it to contain (33.4014 x 0.075) of non-silver which equals 2.505105g of non-silver. What you've done wrong is work out that you want 7.5% of your starting silver weight to be non-silver when actually you wanted *7.5% of your FINISHING ALLOY WEIGHT* to be non-silver Real equation is AG = starting weight of 0.999 silver in grams Total non-silver required = (((AGx0.999)÷92.5)x7.5)-(0.001xAG)
I've read quite a few of the comments and I'm glad to see that I was not the only one to see that the math is incorrect. The .931 that this math creates is closer to Argentinium silver, which has a minimum of.940 I believe. But, alas, this formula does not make .925 sterling silver. However, it's still legally sterling silver by U.S.A. standards and may legally be stamped as such being that it contains more than the minimum .925 to meet the legal threshold.
Thanks! I would absolutely do this. I can buy rounds for much less than finished sterling. I also cast, so making my own grain is a plus. I have a flat rolling mill for sheet and draw my wire into the various shapes and sizes I need.
Thank you, I have been thinking of making my own wire and sheets; I just acquired a rolling mill so the plan was in motion. The formula helps a lot. Buying silver/ sterling that is in sheet or wire adds up quickly, while buying shot and making your own saves a tonne. Thank you
Don’t you make an alloy of like 930 silver? I do it just to be sure if I solder the piece, the total ratio of the complete product is 925 or higher. Thats why I make 950 silver just to be really sure even if 930 is technically enough.
One thing with working with pure silver is that it work hardens and works well for making chain as long as the links are thick enough. I made a few necklace chains with wire that is around 1.5-2 millimeters thick for the links and they stay together just fine. But it's great to know how to make .925 in a simplified way as other videos have been too complicated. And it looks like your rolling mills are from Pepe Tools.👍
The first 1000 people to use the link will get a free trial of Skillshare Premium Membership: skl.sh/gomeowcreations12201 Math is hard so let me break it down for you so it's easy to understand so you can also make your own 925 sterling silver from 999 fine silver. 😁👍 Here are a lot of the items I used in this video: Combo Rolling Mill - bit.ly/ComboRollingMill Wire Only Rolling Mills - bit.ly/WireRollingMills Basic Mapp Gas Torch - amzn.to/3rdnROo Oxygen & MAPP Torch Setup (Much hotter but tanks sold secretly ) - amzn.to/3pbYVW1 Oxygen Tank Small - amzn.to/3apH7T1 MAP-Pro Gas 2x Small - amzn.to/2KEnxrq Acetylene Oxygen Setup like mine - amzn.to/3ajSGLw Basic Smith Little Torch Five Tips - bit.ly/SmithLittleTorch5tips Rose Bud Torch End - amzn.to/3krLoaF Heating Tripod - amzn.to/31BEYyg Crucible for Casting - amzn.to/31ARCxr Borax Powder 1lb - amzn.to/2ISMQoA Cheap Metal Melting Furnace - amzn.to/2H6IPwf Electro-Melt Melting Furnace - bit.ly/Electro-MeltMeltingFurnace Sheet Cake Pan - amzn.to/3nwF1nO Adjustable Ingot Mold - bit.ly/IngotMold 2 Reversible Wire and Plate Ingot Mold - amzn.to/3aqrzP2 Graphite Casting Ingot Mold - amzn.to/34njuGQ 1 OZ .999 Pure Silver Shot/Grain - amzn.to/34s63pc 1 Pound 99.9+% Pure Raw Copper - amzn.to/37wRe6P ---------------------------------------------------------------------------------------------------------- If you are looking for more tools and materials that I use, well you're in luck! I made a page on my website just for that and I'm updating all the time so bookmark it to stay up to date: GomeowCreations.com/tools-and-materials GomeowCreations.com/partners-discount-codes *If you buy any of the tools or materials from my list I will make a small commission at no extra charge to you and it helps support the channel* "This video was sponsored by Skillshare" ---------------------------------------------------------------------------------------------------------- If you would like to directly support the channel you can do so in a few different ways. 1. Like, comment and share my videos 2. You can make a one time donation via Paypal of any amount www.paypal.me/gomeowcreations 3. You can sign up a monthly donation via my patreon for as little as $1 per month www.patreon.com/GomeowCreations 4. You can sign up a monthly donation via my Subscribestar for as little as $1 per month www.subscribestar.com/gomeowcreations 5. Just watching my videos helps out too and I'm happy to see that I have been able to help some may people get into jewelry making. #making925 #silver #jewellerymaking #jewelrymaking #goldmaking #silversmithing #diy #gomeowcreations
Its crazy to me that sterling silver costs more than fine silver! Even if you can find sterling silver in ingot or grain form, it costs more than fine!
Thanks for the video, appreciate the craftsmanship! Would you consider adding the correct math to the description? As is seems to run counter to your intent, 93.1% silver is not sterling, right?
The combined weight will be 33.4gr... 31.1gr(amount of .999 silver) / 33.4gr (silver+copper) = 93.11% not 92.5%. Meaning too much silver, or is my math wrong?
@@GomeowCreations Actually, even better - I've read online that it's better to err on the "over" percentage, if one is at all worried about their reputation. Thanks for the great video!
Thanks for this process video … buying sheet & wire is getting ridiculous with the price of silver at around $30 oz spot right now. I have the opportunity to buy .999 at 99 cents over spot and I’m considering trying to roll my own sheet, not to mention recycling all of my scrap.
For clarification for me, when you add a sprinkle of borax to the silver shot, the borax soaks up the impurities and then they become attached to the crucible, is that correct? I've seen people stir with a graphite rod , what's that do? Thank you buddy.
I don't like elemental copper because it darkening the silver faster + changing the beautiful silver color a little bit, can you replace copper to Aluminum? and, I heard about Argenteum silver alloy
Why not pure silver.I work only with pure silver,it has such a wonderful colour.I dont know what idiot came up with the idea to add copper to silver.Its ruining the colour,it becomes black instead of white.
So for my own personal jewelry I could add extra copper but I’m assuming it would start losing that white brilliant color if I were to do this. I will play around and see how far I can push it especially where I like my jewelry darkened with a patina. But I do want the look of a nice high silver shine on the raised parts so I’ll have a play. And PLEASE if anyone wants to attack me and inform me of what the laws are then spare me because I did say for MY OWN JEWELRY! 😂
Mapp pro is not mapp gas. It’s mostly propane and just gets a few degrees hotter but real mapp gas isn’t made anymore but it got around 5000 Fahrenheit
Come on ! 🤦🏻♀️ How can it be sooo wrong a simple calculation, I can't believe he has gotten this wrong 🙄🤦🏻♀️ You can already hear the insecurity in the voice when talking about the "maths" I can't get over the fact that all basic math concepts are wronged 😢😢 that's why it's important to not only do things based on RU-vid, but go schooling and read from the best literature. I can't imagine Alan Revere's face watching the "maths" 😂part. You can't trust the alloys he sells to his customers that's the only conclusion. An important part of being a trustable goldsmith, silversmith is to get the alloys right. At least in Europe you won't get a goldsmith stamp if you do the alloys wrong. It doesn't matter to me that he says his alloy has slightly higher silver content than 925, it matters to me that his basic math concepts are wrong and he carries on this lack of knowledge through his complete other works. ..
Great video as usual but I was wondering how to turn the 90% silver into 92.5% ? I make alot of coin jewelry and would like to turn my scrap 90% into 925. Can you please help me with the math if I wanted to make an ounce of 925 using the 90%...I know you have to use so much 999 but I don't know the math. Thanks
The following formula will give you the minimum amount of fine silver to add to your 90% silver coins so that the alloy can be co side red Stirling Silver: (Weight of 90% silver coins)x(0.1/0.075 - 1) OR (Weight of 90% silver coins)x0.334
I found this very interesting as I work in the complete opposite direction and refine sterling silver into pure silver. I've actually never liked sterling due to the copper. I find it always has that metallic/coppery taste and I just can't stand it. But still the process of making sterling is interesting from a chemistry perspective.
@@Dan-ji4db Lol...no. But sterling silverware does tend to go into ones mouth at times. :) Even the taste left on my fingers after handling sterling really bothers me. I also find the colour and sheen isn't quite as "silvery" which would make sense.
The formula you used here would make .931 silver. To get the amount of copper to add from the starting amount of silver, divide the mass of pure silver by 0.925 which yields the total weight of sterling you can make. From this you can subtract the weight of pure silver you are adding to get the amount of copper that needs to be added. To get the equation, we start with the fact that the purity of silver in the sterling (expressed as a decimal from 0.000 to 1.000) is the amount of silver per amount of sterling. Sterling purity (0.925) = Silver weight / Sterling weight Rearranging the equation (using a = b/c -> c = b/a) will show that the silver weight divided by 0.925 gets the weight of sterling. Sterling weight = Silver weight / Sterling purity (0.925) If you know how much silver you have and weight of sterling it can make, then subtract the weight of silver from the weight of sterling and you get the amount of copper to add. Copper weight = Sterling weight - Silver weight Combining the two equations by replacing the weight of sterling will get you a way to calculate the amount of copper to add from just the weight of pure silver you are starting with. Copper weight = (Silver weight / 0.925) - Silver weight
Your math is not quite correct. The correct math (Weight of .999FS) x (7.5/92.5) = weight of copper needed to make sterling silver Or (weight of .999FS) x .0811 = weight of copper needed to make sterling
I was 100% going to do this even if I didn't find any instructions on it I knew it could be done so I was going to try, but I'm very glad to know that I was not very far off on technique thanks for the informative video
If you have silver that has been heated too many times and reticulated, would adding copper return it to a non reticulated state? Great video, good to know the copper amount to add.
Always super informative!!! Thanks Randy!! Cant wait til I have my set up to start making my own sheet and wire!! Hopefully this coming year. 😜 In the meantime I purchase ready made sheet and wire and save all my scraps😁
@@GomeowCreations Strange, I always knew it to be illegal, but it's only illegal if you plan to make a profit? Wtf? They just don't want people melting pennies into copper and scrapping them for higher value I guess. Odd.
thank you . great demo. i buy my sterling silver from RioGrande. just to let you know that an ounce of fine silver cost 1 dollar more than sterling silver from that supplier !. so why go through the trouble and pay more to make sterling silver ??!!.
You can do what you like but I wanted to have fine silver on hand if I needed it. How I look at it, I'm going to have to melt the metal anyways so I can just mix it on the spot and make what I need at the time. I can make the mix and making it right into a casting or ingot as well.
It really don't matter much, I think in this video it was just some wd-40 you can also just not turn on the o2 on your torch and cover it in soot and that will work the same.
Thank you for the video. I bought new silver 925 jewelry, but it is less shiny than expected. I wonder how I can converted to brighter like pricy brands
this math is wrong. your copper needs to be .074 or .075 of your *final* weight. if you take 7.5% of the lesser fine silver weight, your copper is short. on one ounce its pretty irrelevant, but at an industrial scale, its alot.
Hi! I really like your videos, but two things. First, PLEASE encourage people NOT to melt old coins for metal stock. Not only do they carry a premium, but that is because they aren't being made anymore, so melting them is UNSUSTAINABLE and deprives future generations of these parts of our history that we have a personal experience with, they won't get to have. Silver rounds/bars and casting grains abound! Please use those! Secondly, your math is interesting. There are different ways to 'figure'. If you HAVE 31.1g of silver, and you want to use all of it, then divide it by .925 and the difference is your copper needed (2.52g), though if you decrease it slightly, your Sterling will test out for sure. If you want to end up with one troy ounce total Sterling after, then multiply 31.1x .925 (28.77g) for your silver measure and the balance (31.1-28.77=2.33g) for your copper. You took 7.5% and added it back in. It worked because it kept the silver level over 92.5%. Otherwise you'd get penalized on assay or fail a product test. Thanks again!
Hey Randy, where do you get your pure copper from? I like to know what reputable sources to buy from. Also, does it matter on the type of copper? I worked in a machine shop for a few years and there were some different kinds that came through the shop
I'm more or less comparing the propane and mapp gas hand held disposable tank torches you can get from the hardware store. I have both of them and have tried melting some silver with both. The propane never got the the point of making the metal a liquid ad sor the mapp gas it was able to along with being able to pour it for some small castings.
Hi... I am here as I am kinda curious about silver. I got a sterling silver earrings. I was wondering whether it will tarnish or not. So I ended up watching your video. Yay.
Boil water and put your sliver in the boiling water with Tin foil shiny side up and put in a tea spoon of baking soda and bam all the Tarnish is gone 100%
Hi. Like you videos, very informative. Can you give advice if you know where is good place to buy gold materials for making some jewelry for hobbyists, thank you
Exactly. You can also use 999 silver for bezels and it makes it a lot easier to shape around your stones. It's just handy to have if you need something you can just make it but if it's just a hobby you might be better off just buying 925
Its including 1964 on quarters and dimes that are 90% silver not before and i think the pennies are 1981 and before with some 1982 pennies that are 95% copper and 5%zinc
I have a smith oxy/acet and a electric furnace. I haven't cast either yet and was wondering which is more economical? An electric furnace running at 1800watts for an hours would seem pricey maybe for electricity. Also, what level shade of glasses would be good for the smith torch? Thanks
Hey! A scale that does grams and ounces... That's about all the materials I actually have on hand. Glad to see I have something I don't need to order. 😂
