Silver pitting when annealed?

Hi,

yes, always feel free to ask any questions you have! None are too big or too small!

I did not mean to discourage questions, i started to post comments and then decided that the practical casting book would provide more comprehensive information than i ever could!

and, the comment about CAD printed (various proprietary) resin model burnout versus wax model burnout, that someonw mentioned, reminded me that adds another newer technology, with its own idiosyncrasies too!…(which i cannot recall if it is covered in the book…) as well as different investments, etc…

it sound like your pitting problem is metallurgic / structural and occurred as a result of burnout/ casting… it does not sound like the metal itself is contaminated…(?)…

…many people recommend adding about 50%(?) new metal to melts with recycled metal…perhaps someone will add to that comment…

julie

I intentionally stayed away from acetylene. For one thing, I set up a workshop in my house. So… this is where I live. I’ve got all the equipment for a workshop, but I’m in my house, and acetylene is dirty, has more fumes, and is a lot more dangerous. I’m not trying to blow anything up over here or catch the building on fire. Plus it’s not some well ventilated garage or workshop I’m working in. So I chose propane. I haven’t noticed any fumes at all from the propane, it’s worked out really well and hasn’t even put soot on anything other than that one crucible. I have fume extractors just in case, though. I have to be very careful because obviously I don’t want to endanger my family, but also because my lungs are complete and total crap, I have really bizarre severe allergies to random chemicals, and my throat likes to randomly swell shut if it gets irritated. So safety is absolutely priority one. I wear masks, goggles, etc., when doing anything that might have fumes or create any sort of dust. I have to be downright paranoid about it because I don’t have a desire to stop breathing or have to drop everything and go to the ER. So far it’s worked, though, I haven’t had any issues with stuff, the fume extractors work really well, and wearing a mask is super helpful when I’m bent over working with the flex shaft. I try very hard to create as little dust as possible, too, even if that means it takes longer to do something. I’m the canary in the coal mine, if there is anything remotely hazardous in the environment, even in small quantities, I’ll know first because my throat swells and I just suddenly can’t breathe.

Anyway, enough about that, I want to make sure I’m understanding you about these torch settings, so I’m going to try to paraphrase to see if I got this right. So too much soot means too much fuel and not enough oxygen, right? Hissing means too much oxygen? Too much oxygen will blow the torch out. Now here’s where I’m getting lost. You’ve got your primary regulators and secondary regulators. I feel like I understand the process with the secondary regulators. What I don’t understand is how the hose pressure from the primary regulators affects the torch? What I’m aiming for is a flame more on the oxidizing side, more blue and not so bushy and yellow. A reducing flame has more fuel, has more yellow, is bushier, not as hot, and it also causes more soot, right? A slightly more oxidizing flame is cleaner, hotter, and more blue? But what does the hose pressure do to the flame at the primary regulators? I’m not happy with the results I got when I set the primary regulators to their recommended settings, I liked it better before when I had it on my own settings, it didn’t create a bunch of soot then. I’m pretty sure I had it set so the pressure on the propane was much lower, the pressure on the oxygen was a little higher. The recommended settings have that reversed, and I ended up with a much more reducing flame that covered everything in soot no matter what I did with the second regulator settings. A reducing flame has more fuel, and an oxidizing flame has more oxygen, right?

I was debating on MAPP gas. I looked it up. And I read this really weird thing, it’s so bizarre I’m not sure it’s true or not. I read that MAPP gas isn’t actually made anymore and what they’re calling MAPP gas isn’t real MAPP gas but something completely different. Is that true?

I totally get what you’re saying. There are definitely big advantages to training in the traditional way with a teacher and a classroom and to doing repetitious tasks. And perhaps I would consider it more if not for my current situation. I have two kids who are severely disabled. They’re in a LOT of therapy in our home so I homeschool them so they can do all this therapy, they have to be supervised 24/7, someone has to be awake at all hours because they’re also insomniacs so my family helps me with them. I rarely ever leave the house. All three of us are also immunocompromised. Literally every time we go somewhere, we get sick with some random virus, and it’s like, great, we have the plague again, and our immune systems are terrible and don’t fight things off well so we can’t risk going out much. Lot of health problems all around. So I work from home, we can’t go out much, and I need to be with them at all times. It probably sounds like a lot to deal with, but I’m happier than I’ve ever been, I enjoy being with them, they’re my two favorite people in the whole world. So I rarely leave the house, but I’m constantly surrounded by people. For one, I always stay with my kids. Sometimes we’ll have nine therapists in our house at any given time working with the kids. I turned our house into a kid therapy clinic and a school, we’ve got just about every toy, game, and educational thing you could think of, and my parents are always here as well. So going back to college or leaving to do classes just isn’t an option, I can’t leave my kids. I would be reluctant to do classes anyway because I am burnt out on college, but with the added circumstances it just isn’t an option. But I’m happy with it, yanno? I know my place in this world and where I belong, it’s here with my children, and I’ll take care of them for the rest of their lives. And I just pursue my own interests right here around them. They’ve been really curious about the goldsmithing, I have a whole area barricaded off where my work area is but where I can still see them and keep an eye on them, but they’ll come over and stand at the entrance and just check out what I’m doing. The setup has worked out really well, I just have to be very determined to learn because it’s all on me. No one is going to just easily hand me the knowledge or guide me, I have to do that myself, so I keep a list of research questions and things I want to understand better, and I just hunt until I find answers and figure it out.

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You’re totally fine, sometimes a book really is just the best answer to a question! I’ve been hunting down books and trying to figure out which ones are the best for each topic, so your answer was very helpful. I’m not really happy with the book I ended up getting on casting, now I know which book is better that I should get and study.

I’m undecided how I feel about 3D printing. It seems like cheating lol. I get how it can be very helpful for mass producing, but that’s not something I want to do. I’m not doing goldsmithing so I can play around on a computer all day, kinda defeats the purpose. It does produce very detailed and accurate pieces, but I feel like a master should be able to do that by hand. At any rate, it’s not something I’m planning on pursuing any time soon if at all, I’d rather learn the traditional methods and best practices so I’m going to start with the book you recommended and just practice practice practice. Thank you again!!

the primary regulator steps down the pressure of the gas from bottle pressure to much lower, the secondary controls the hose pressure AND handset pressure…those specs have to keep within the limits for your equipment… the knobs adjust gas flow at the secondary pressure. I have adjusted the primary regulator settings, especially one the bottles are running low on oxygen and fuel… in the case of propane, it’s not that critical… oxygen at the bottle below 200 PSI not only means you’re running out, but due to the lower pressure, less oxygen is flowing from the bottle to the end… setting the secondary higher to increase pressure in the delivery end has it’s limits…gas flow is also dependent on pressure at the secondary…if the bottle is near empty, the pressure will drop at both regulators, when gas is actively flowing through them… knowing how much propane or acetylene is left often a matter of running out… propane bottles at room temperature will maintain the gas pressure until it’s almost gone… same for acetylene since it’s not free, but dissolved gas… I have an 80 cubic foot 02 bottle…it goes farther between bottle changes… using a propane tank for a gas grill give you more propane at a cheaper cost, but now require adaptors to interface a gas grill bottle with the torch regulator…the design of the gas grill screw was changed long ago for safety and anti flash back…

I never use acetylene indoors…it’s too dirty and sooty… prior to adjusting… you have to start the acetylene flow and light it before you start the oxygen, otherwise you’d get a pop… a big explosive one if you can’t spark it quickly… when you shut the torch down, you have to shut off the oxygen first, before shutting off the acetylene…otherwise it will pop again as the flame blows out… more soot.

the hand set knobs are there to control gas flow at the secondary pressure… too little oxygen OR too much fuel, makes for a reducing flame. Too much fuel or too little oxygen creates an oxidizing flame…
It’s NOT the absolute setting of the knobs but the relative proportion of oxygen and fuel that is being supplied at a set secondary pressure…for s stronger flame, both knobs can be dialed up for more gas flow… it will give you a bigger hotter flame if the oxygen and propane are kept balanced…,less will give you flame… those are all within limits of what your torch is able to handle at any given secondary pressure.
Please note that acetylene is C2H2… it requires 1 1/2 oxygen molecular to burn it to 2C02 and 1 H20…
Propane is C3H8… it takes 11 02 molecules to burn one molecule of propane to 3C02 and 4H20…
Another hidden problem could be that the torch tip is dirty on the inside…that will alter the flow of gas and throw the flame off… cutting torches have to have their oxygen jet holes constantly cleaned… gas pressures and adjustments of flow are much more critical to cutting and welding steel with oxyacetylene… cutting steel requires a lot of pressure to blast pure oxygen thru preheated, melted steel in order to cut it…welding doesn’t, but I use an arc welder instead of trying to weld with gas which doesn’t penetrate and gives a weaker seam.

It’s true that MAPP gas is no longer available… Bernzomatic sells “pro gas” which is supposedly hotter burning but the contents are proprietary… MAPP gas was discontinued since commercial and industrial users found that acetylene was cheaper and that MAPP had no advantage for their purposes…Progas is expensive too and with an oxygen source, there’s no reason to use it…

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true, it’s now called progas by Bernzomatic… still expensive. see above post for details.

I can understand your situation. My son has MS. Thankfully because of Physical Therapy he has graduated out of his wheelchair. Don’t get me started on what the side effects of fluoroquinolones do to your body. Other than books and classrooms there are a couple of methods to check out. Doesn’t mean we wouldn’t be here to answer questions, but each has it’s advantages on learning the basics. One is on Facebook. Look up Alan Revere. He is teaching or at lest guiding people through his book, which use to be what he taught in person. It has little You Tube videos to go along with each project. Problem with them is it is not in depth teaching. Decades ago I went through the Revere Academy in person. The second and the one I would highly recommend is Lucy Walker. I follow her on Instagram. If you join her academy You have access to her wonderful videos that in my opinion are excellent. Even old dogs like me can learn a better trick to old problems.

Would your children when they get older be able to do jewelry work? If so they might be able to do little bits now. This is not knowing the whole situation, but just wondering.

I’m one of those who learned doing this craft without any computer help. Yet my hubby is a VP in an IT department for a global company. Once a topic on here goes the way of computers, my eyes glaze over and I go out in my workshop and smash metal old school. Hang in there. Creativity is a wonderful out let for you.

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Usually silver and other non ferrous metals pit only when over heated while melting. Since you only got it to an annealing temperature I’m gonna make a wild guess that the issue is not the torch or the heat you took it to.
I would recommend that you take this question to James Binnion. He is just about the smartest metallurgist I know and he’s very approachable. This is the book that he wrote that I believe that every metalsmith should have in their studio. Jewelry Metals: A Guide to Working with Common Alloys, Book - RioGrande

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I’m going to take everyone’s advice I’ve received, this is very helpful. I’ve looked at a lot of online training programs and definitely like Lucy Walker! I like Andrew Berry as well, I have a membership with him. The first one I signed up for was London Jewellery Academy. I’m cancelling that membership, I’m very disappointed with it. They only teach how to work with premade sheet, wire, and metal clay. They don’t teach or encourage rolling mills, alloying, melting, or casting. I guess they wanted to make a program that would be “safe” for people at home. I don’t understand this at all, you can be safe with a torch, just don’t do anything stupid and make sure you read the manual first. So I’m cancelling my membership with them and opting for Andrew Berry and Lucy Walker. I like Andrew Berry because he talks really fast and pelts you with information and pretty much answers every question you think of as you think of it. I take really detailed notes. It also greatly helps that I have an eidetic memory, once I’ve seen or heard something (as long as I’m actually paying attention and not lost in my head somewhere) I pretty much remember it forever. But taking detailed notes cements it even more. I don’t usually have to refer back to the notes, the process of taking the notes is what helps. At any rate, I’ve got great notes lol.

I don’t know much about MS. I know some people who have it to varying degrees of severity, one is in a wheelchair and the other isn’t. I don’t know if my children will be able to ever do anything to tell you the truth. They’re both pretty much nonverbal. They do have some language, they can ask for favorite foods, toys, activities, but that’s about it. To be honest, I would settle for them just learning how to shower themselves. They’re 11 and 9, severely autistic, but I have no idea why or where it came from, though there are always theories and speculation. Mentally they’re like toddlers, just very sweet, innocent, pure, and loving. They’re everything that is good in humanity, completely without guile or malignancy, just completely and totally good and sweet. They’re both really smart, but there’s just this block on their ability to actually utilize or express their intelligence in any sort of functional way I guess you could say. My youngest son has an eidetic memory. His eidetic memory is better than mine ever was, it’s really a sliding scale of how good your eidetic memory is. Mine is decent. But his is absolutely phenomenal. That boy can see an 8 syllable word once, you tell him what it says, and he remembers it forever more. Yet he has absolutely no interest in reading even though he reads with ease lol. They both also have apraxia so their speech is very difficult for others to understand, it sounds very garbled and odd. I can understand them, but others have a difficult time learning the way they talk. They seem to understand each other, though. They’ll be standing there doing their own thing and the little one will suddenly say some complete gibberish and his brother will jump up and go turn the light off or something. And I’m standing there like, ok, what just happened? Lol. So I’m not sure how much they would be able to do. I explain and show them things constantly, and they seem to understand a lot of what I say, but being able to actually use that information and do it themselves is a different story. People with severe autism have an average life span of 36 years. Even if they make it to 50, I’m sure I can live that long and just take care of them their whole lives. Ideally, that’s what I want, desperately. I don’t trust anyone else to do this job, I want it to just be me and them to be taken care of and enjoy their lives in whatever way that suits them best. I really feel like I won the jackpot with my children, I think they’re the two greatest kids the world has ever seen.

Awesome, thank you, another good book to get and study!

Ok! I read what you wrote very carefully about four times, and I think I get it now. I did my first cast today. Twice actually. First time was a bust. Second time was much better. And I think I understand this torch business a little better, too. Some weird things happened with the cast that I don’t really understand and wasn’t part of anything I’ve studied, but that’s a separate issue. So it’s really just all about balancing the propane and the oxygen. You can raise them both, you can lower them both, but they have to stay balanced. I just kind of played around with it until I got a good hot flame going that melted the silver a little faster. Too much oxygen, the silver started to harden. Not enough oxygen, the silver started to harden. It seemed to work out much better than what I had attempted previously. The only torch I’ve ever used before this is just a big butane torch, so this is new territory for me, and the margin for error is kind of nonexistent so I want to make sure I get it right. Your intense expertise is amazing, btw, you know more about the chemistry of it than I probably ever will, it’s really impressive and helpful. Thank you so much!!

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I learned gas oxygen basically by trial and error…you have to keep playing with the knobs until you get the flame for your need… for soldering, only a small flame is needed, so both gas and oxygen can be turned down, but kept in balance… the same goes for a melting large flame… both up, but balanced… it’s not that hard to do, once you get the hang of it… I’ve played with the knobs without using the flame to heat anything… just to change the total size and also to see how oxidizing and reducing settings would color the flame… My advantage was that I first used oxyacetylene … it’s easier to adjust since acetylene has so much carbon in it… propane, less relative to the hydrogen… within the limits of your torch flow (even a balanced flamed at high flow will blow out), there’s no single “right” setting… by varying the TOTAL amount of gas flow, but maintain a balance, you should be able to get anything from a small, hot slightly oxidizing flame, to a large hot neutral flame. I don’t recommend strongly reducing flames because they aren’t as hot and create more soot.
For melting to cast, use a large neutral to slightly oxidizing flame, by turning the flow up on both the knobs… it will be hot!. and melt quickly… superheating the metal will allow for a better cast… but don’t over heat too long with too much oxygen… if you’re using sterling, a small amount the copper will burn off…but this is more of a theoretical than practical concern. I did this deliberately to fire refine sterling with solder, by injecting pure oxygen into the metal using my steel cutting torch, to make fine silver…blowing 02 into the metal burnt off the zinc and copper…
For soldering, a smaller less hot flame is easier to control…and also be careful… gas oxygen is a lot hotter than gas air, so it’s easy to overheat things.

The easiest way to start is to turn the gas on first, gauge the size of your flame, then add oxygen… add more gas and oxygen if you need a bigger flame…when turning off the torch, always turn off the oxygen knob first, then cut the gas off… this isn’t as crucial as it is with acetylene, but you can still get a pop as the flame blows out if you cut the gas first…

I’m sure that you will find using gas and oxygen is far easier to work than just gas and air, once you get the feel for it… good luck and have fun…

PS: if the silver is hardening in the crucible, then there might be two things going on… one is that there’s not enough total heat in the gas flow to keep the metal molten completely… you’d have to turn up both the gas and 02 for a bigger flame…The other thing is that the silver could be crystalizing… if it’s crystalizing, it means that you’re underheating it for too long… that would not be a problem at all, since it can be remelted easily with a hotter flame. Fine silver tends to crystalize more than an alloy…a little superheat helps with a smooth pour…the metal won’t harden instantly when it gets into the mold, giving you better detail. you can judge by the color… bright red yellow to more yellow hot is at 2,200 degrees F… If you’ve seen pictures of hot lava flowing at Kilauea volcano, notice the hottest color… that lava is between 2,000 and 2,100 degrees F… the melting point of pure silver is 1,761 degrees and sterling 1,640…a very bright red is 1,800 to 1,900 degrees and is sufficient for a good pour… you don’t need to heat it any hotter…

Learning to control gas flow is far more critical when working with steel… I started using my acetylene torch for cutting up scrap steel sheet and rebar for wind chimes and wind mobiles…ferrous metals quickly burn up in an oxidizing flame, but a jet of pure oxygen is what does the cutting, by literally burring thru the steel. welding with gas is nearly impossible to do well… a reducing flame is needed…otherwise the molten metal would turn into rust…for welding, using an arc welder is far easier. I also have used my torch, with a strongly reducing flame to harden tool steel for punches and other small home made tools…it adds carbon to the steel… Learned gas mixture balance doing that first… again, best wishes and good luck, have fun with your torch.

the two posts that I wrote back to you are out of order… the second should have come out as the first.
I deleted one of them because it was a duplicate… oh well, it’s all duplicated and messed up anyway, I give up… steve

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Hi,

regarding the smith rosebud tip

when using disposable 1lb propane tanks, i was advised by someone at Paige Tools to only use rosebud tip with a tank that is that is more than half full.

he advised to get a separate 1lb disposable tank, dedicated for use with rosebud tip, weigh it when new, weigh it before each use, and do not use tank if half full or less.

then, use that that tank with regular smith tips after used halfway, and get another new tank for the rosebud,…

i forget the reasoning behind this advise…i believe it had to do with tank pressure…(?)…

when new, my 1lb propane tanks weigh about 1lb 15.5 oz.

the net weight on the tank is 1lb

so, i am assuming that the metal tank itself weighs 15.5oz

so, when half full, the tank would weigh about 1lb 8oz

(1lb= 16 oz)

julie

I"m a little confused by something in this thread. Don’t you use a slightly reducing flame, one that is just slightly bushy and doesn’t roar like an oxidizing flame, to cast? And you keep the flame on the metal as it pours, right? Actually same for soldering, right? And it important to use the hottest part of the flame, just at the tip of the inside cone, right? There shouldn’t be a problem with melting about an ounce of silver with a Smith Little or similar torch if you use the right part of the flame. Getting too close in, inside the come, or too far away from the tip of the cone, will result in lower temps…let me know if I have this wrong. -royjohn

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Sounds right to me royjohn. If not, I have been doing it all wrong. I do use a bushy flame for annealing, actually, an from entirely different torch…Rob

Hi,
i work primarily in sterling silver, and i dont really ever use an oxidizing flame…i cannot recall what they would be used for…

julie

Hi Dana, I’m right there with you on stepping up from a butane torch to oxygen/propane Smith Little torch. There’s SO much to learn about flame control, etc. Sometimes I default to my creme brûlée torch out of convince but it’s limited so onward I go, learning about the flame with Smith little. There are so many wonderful helpful smiths , like all those here responding to you question. That being said, there’s nothing like direct observation from a teacher. I’ve found there were things that I just didn’t account for and online couldn’t address the problems I was having. When doing something new I research and read like you. For me hands on instruction is often the way to go, especially with mixed gasses. Wishing you the best! :smile: