Making Red Tombac of Paris - Alpha Brass - Copper, Zinc and Lead 

pitina? ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-II-ieVyVcjw.html

I watched that patina video, great results. Will probably give it a go sometime. Cheers Andy 🍺🥂

MeltandCast Hi mate just got in to casting metals, got a new Devil forge. Just wanted to no what crucibles you have a got. Are they Salamander ones or procast as I have read they are good. I have got some from China but after spends a lot of money on them there always really bad Quality. What do you recommend

All mine are Salamanders as they have a pouring lip. I've not heard of Procast before... The sizes I use (assuming you have the 10kg furnace) are A6, A8 and A10. I use the A6's most often as you'll likely need a different crucible for each metal. The A8's and A10's are almost identical size wise but the A10 does hold more. The furnace might struggle to heat an A10 full of copper but would be fine for lower melting point metals such as aluminium. Both the A8 and the A10 are a bit of a tight squeeze. You'll need some well made lifters to slip down the edges of the crucible to lift it out as the space between the furnace wall and crucible is quite slim. I'd suggest getting a few A6's and the pouring shank and lifting tongs from SDTS engineering. They aren't the cheapest place to buy furnace gear but it will get you up and running. Once I had the A6 lifter I got a local engineer to make me lifting tongs and shank to the same design telling him to flare the pouring shank to grip the crucible and ensure the lifting tongs slid down the edge of the crucible without wasting space. He did a sterling job, they work perfectly and were half the price. The cheapest place I have found in the UK to buy crucibles is from EF-Supplies based in the North of England. They are distributors for Morgan Salamander and are half the price of everyone else. You can email Michael at EF-supplies or give them a call with your needs. I usually buy 3 or 4 at a time. Castree kilns also sell cheap Salamanders but rarely have any in stock. You can buy fluxes and other bits and bobs from Castree too for much better prices. SDTS also sell lots of foundry gear but at slightly higher cost. You can look at the crucibles on Castree kilns to see the size chart and dimensions before ordering from EF-Supplies. Hope this helps. Best wishes Andy 😎👍🍺

MeltandCast wow thank you so much for your reply mate, that’s fantastic info for me as I was getting really stressed out trying to find a supplier

Cheers Bones 🍺😎🥂

Thanks Ford, glad you enjoyed it mate. Cheers Andy 👍😎🍺

Rofl "Golden Fart" !! Stick with it mate, you learn more from your mistakes than you ever do when it all goes perfectly. I often think I am doing things right, more often than not, I do it wrong. The wonderful casting community here on YT always put me straight and I learn something new every time I make a video. There are always ways to improve, it's a constantly evolving hobby, I love it. Cheers Andy 👍🍺😎

Thanks Macio 🍺😎

Thanks Heimo, glad you enjoyed it mate... Andy 🍺🥂

Cheers Reed 🥂🍺😎

Yeah I can't wait to get some tin... having camera issues at the moment so I need to upgrade my gear before I start with bronzes and Nordic gold... Hopefully it shouldn't be too long. Cheers Andy 😎🍺👍

@@MeltandCast nice and hopefully you can get it soon has well

Thanks Awldune, that was what the recipe called for... Must admit it wasn't very red at all. The streaks were not visible at the time of polishing. It would be nice to know it it's repeatable, that grainy effect could be quite desirable in some castings I should imagine. Cheers Andy 🍺😎👍

Thanks Rockelec, The book is called "Woldman's Book of Engineering Alloys". I think it's up to the 9th edition now but you can find a earlier editions for a fairly sensible price rather the the £200 odd they want for the latest version. The info is essentially the same, might just be missing a few of the most modern versions of some alloys. Cheers Andy 😎👍🍺

Thanks!! 😁

Thanks Pixel, I've not heard of Niello before.... something else I'm going to have to experiment with now.... haha. Cheers Andy 👍🥂😎

Exactly !!! I was hoping it would be more of a brown / bronze colour. That's what it's called though... Back to the drawing board !!! Hehe. Cheers Andy 🍺🥂😎

Thanks Avionn 👍😎

Haha Thanks Ronin... Sorry, I didn't mean it to come across that way... I was quite happy with the bar and the graining on it was pretty cool. In all honesty I thought I had poured it too cool and the ingot was going to be all layered. Actually it wasn't too bad, you can see the difference on the Vienna Tombac which was way more layered. In terms of the colour though neither of the ingots were what I was after. I thought it would have been a lot darker with the lead added... Not sure why... I just thought it would... I wanted to see if it would be any good for my backgammon counters, but its too yellow. I will be using a 25% silver 75% copper mix for the counters on next weeks video which has a beautiful sheen and with some gold leaf added should look great. I try to point out as many flaws as possible as most of the time they are avoidable and can, with better casting practice be avoided. Things like leaving the molten metal to soak the heat for a while and using really hot moulds can make a massive difference to the ingot quality. Not leaving the metal to soak the heat for long enough is a mistake I regularly make and has been the cause of several failed castings. Cheers Andy 🥂😎👍

I sound a bit harsher than I ment to. They are quite good

Beryllium is one of those "don't touch with a very long barge pole metals" Incredibly toxic, you definitely don't want to be messing with that stuff no matter how small the percentages. Be very suspicious of copper metals that don't look like regular copper, always research them before melting, it might save your bacon !! Chromium copper, cadmium copper and beryllium copper are all a no no. Cheers Andy 🍺🥂

@@MeltandCast thanks for the advice. Will definitely keep that in mind next time i want to melt some suspicious looking metals.

Beryllium copper is a reddish colour most commonly used in spark proof tools. Chromium copper is used for strength and heat resistance, often shiny and bright with little oxidation (used in welding gear, connectors, circuit breakers etc) and cadmium copper is used for arc resistance (spring connectors, sockets, plug in connectors, power boxes, electric blankets etc). It's worth being a little wary of copper not sourced from wire or pipes. Often the amounts of these metals you are likely to come across are small compared to things like wire and pipe... best to just avoid them entirely just to be safe. I don't mean to go into one, I only mention it for the benefit of others who might read this too. Cheers Andy 🍺😎🥂

Haha I aim to please !!! Cheers 🍺👍

Cheers James 🥂🍺😎

@@MeltandCast cheers to you also.

Thanks David 🍺🥂

One of my favourites so far has been the Abyssinian gold. 90% copper and 10% zinc. Nordic gold would be a nice colour if you have any tin - 89% copper, 5% aluminium, 5% zinc and 1% tin, but I haven't tried that yet... Prince Rupert's metal was also used as a poor mans gold but the casting I made was too difficult to polish to see it's true colours. Any brass with less than 37% zinc are alpha brasses and should be more resistant to tarnishing. Small amounts of aluminium also causes a layer of aluminium oxides on the surface which can also help protect the metal, but you'll have to check that online. Don't quote me on this but I think it's the acidic elements that cause the tarnishing such as rainwater etc. Cheers Andy 😎👍🥂

Thanks Luddite. Would the introduction of iron oxides not introduce more oxygen to the melt increasing porosity ? It's a neat idea but red iron oxide consists of Fe2O3, would it not add a load of oxygen which would then need to be removed by introducing a more reactive ingredient such as phosphorus or lithium ? I think your right on the graining being oxides, I think these are a result of the lead migrating to the outer areas of the metal due to it's lower melting point. When I polished it last week none of those marks were visible and it was 'clean' and shiny. A week later and the lead has shown signs of oxidation which I should imagine is the cause of the graining. Given the right casting this could be quite desirable if it could be repeated, especially with a higher lead content. I do have a small bottle of argon gas, but due to the huge amount of heat in the furnace I wonder how long you could keep the gas around without it rising due to the convection currents. The only method I haven't tried yet is dissolving the copper into the zinc at low temperatures, however the amount of copper that can be dissolved is finite, kinda like dissolving sugar into water. Mercury isn't a metal I fancy playing with too much, I don't understand enough about to comfortably experiment with it. I'll leave that one to Cody's lab I think hehe. I'd be interested to understand more about the red oxide idea though if you could point me to some more info...? Cheers Andy 🍺🥂😎

@@MeltandCast, So much I could say here but I only have limited time. :- 1, Referring to the Ellingham diagram it is obvious that molten copper will NOT take up oxygen from iron oxide. Zinc will have some tendency to do so but there is so little of it present (about ½ what you think at a guess!) that its activity in this way would be very low. 2, Generally it’s a bad idea to do a really intense mix, all this will do is stir in gases from the atmosphere - principally oxygen and hydrogen (applies to ALL molten metals) 3, I would not have mercury anywhere near my foundry - it is very dangerous stuff - even at room temp it gives of vapours highly toxic!!!!! 😱 4, Regardless of how you make your brass zinc flaring will occur - the more zinc the lower the temp at which flaring will occur. As luck will have it the temp at which noticeable flaring begins corresponds (roughly) to the correct pouring temp - old timers used this as a guide to the correct temp. (Takes skill and practice though) There are ways of limiting the flaring which I have never seen used on YT 5, Lead will NOT alloy with copper the two are mutually insoluble. In the solid alloy the lead will be present as very small spheres of pure lead often they will have gravitated to the bottom of the casting concerned Would suggest that you do not use zinc for you counters as it will just go all dull and grotty looking. Suggest possibly that you make from steel (turned) and blacken with a molten salt nitrate bath. Alloy make up is a difficult task full of traps for the unwary - I have never yet seen alloy make up done anything like correctly anywhere on YT. For example, most who attempt 90:10 Aluminium bronze by adding 10% aluminium to pure copper are fooling themselves as they would likely lose ½ that aluminium to oxidation - thus making maybe the equivalent of a 95%: 5%. Zinc is even worse in this way -I doubt your first effort has anything like 2% zinc in it…Martin

@Olfoundryman Thanks Martin, I love it when you come on here and set the record straight, I really appreciate it. Clearly I need to spend some time on the Ellingham diagram to understand it more. OK you're probably going to have to set me straight here again, but am I understanding this correctly ? 1. Because the zinc line crosses iron line the zinc will absorb the iron oxides at around 1200C (likely the temperature the copper is at in the crucible) ? 2. Due to the separation of lines between the copper and the iron, oxide take up will not occur ? 3.Aluminium, magnesium and calcium could all be used as a reducing agent "in theory" as the separation of lines is greatest between those metals ? 4. The melting point of aluminium, magnesium and calcium are all below that of copper and iron which if in it's liquid state would enable them to be effective oxide reducers of iron and copper ? 5. I assume the metal needs to be in a liquid state to act as a reducing agent for metals higher up the diagram ? Therefore.... 6. Magnesium and calcium would be a poor choice of reducing agent for copper as its boiling point is below that of copper and likewise calcium would be a poor choice for iron as its boiling point is below that of iron ? 7. The best choice would be aluminium ? Appreciate you're busy - If I have it all wrong just tell me to do more research or am I getting the jist of it ? I'd be interested to know your take on reducing flaring when making brass although I am nearing the end of my brass experiments for now... I'd still like to try a method suggested by a true expert in the field to see if I can nail it. The counters need to be cast as there is a "medusa face" in the centre of each counter, it was my Dad's old backgammon set so I am keen to use the original counters. I will probably opt for copper for both sets of counters based on your suggestion. I will use a heavy dose of liver of sulphur on one set to blacken them, with gold leaf on the 'medusa faces' and lacquer to finish. Polished copper will also show off the gold inlay well. I'll try adding some phosphur copper to the melt when I do this to reduce oxygen in the melt. The cudox tubes I have are supposed to be for a 50kg melt but only contain around 14 grams of phosphur copper. Assuming I make a 5kg melt would 1.4 grams of phosphur copper be enough to reduce the oxygen, or should I add more ? Lastly I am thinking of adding some silver to the copper to increase fluidity in the mould at around 5%, does that sound like a good idea ? The silver addition gives a lovely sheen when polished. Best wishes and thank you once again for your continued teachings !!! Andy

Andy, Andy, I too need to spend some more time with the Ellingham diagram to understand it more. In truth my understanding is very basic and pretty much limited to - A;-“any reaction below another will likely occur in preference to the one above” B;- “ the greater the distance between the two reactions the more heat given out as the lower one reverses the upper one” C; - “An initial Kick might be necessary to get things going”. D;- “things are complicated by there being more than one oxide for some elements (3 for iron!) E;- “things are complicated by elements/oxides melting or particularly boiling F;- “removal of an end product e.g. by boiling off will likely move the equation in the direction that produces that product G;- “extent of the overall reaction dependant of the % of reactants present” Right or wrong that is my poor understanding. I always like to think of thermite as an example - iron oxide (Fe2O3) is reduced by aluminium to iron and the aluminium oxidised to alumina (Al2O3). Because of the large distance between these reactions on the Ellingham diagram a very large amount of energy is released - so much that the iron produced is not only molten but has enough superheat that it can and is used to weld railway lines together. But despite the great distance on the diagram the reaction still needs that initial kick with some sort of igniter to set it off - but then, stand back! If you can find a very competent Chemical engineer (Is there one out there who can come on board?) and get him to explain it as I do not really know enough to provide a dependable interpretation To your questions 1, I am uncertain but I feel it is very much complicated by zinc being a vapour at this temperature, by there not being that much (%) of it present, and by the look of the diagram with its dotted line above the boiling point of zinc ending in a arrow pointing ever upwards I may not be the only one uncertain! I think that under the circumstances a reaction between the zinc and iron oxide is probably unlikely - Much more likely is zinc reacting with copper oxide. 2, Yes, but again complicated and a little uncertain (in my feeble mind) by the possible reaction betwixt Cu and Fe2O3 to produce Cu2O and Fe3O4 above about 680 deg C. Curves here are close together so any reaction is likely not very energetic or very complete?? 3, Yes, but again complicated by possible deleterious end products. 4, Yes, but the term “effective” needs to be thought about. 5, In truth I do not know but I strongly suspect not - many such reactions (think of gun powder and other solid rocket fuels) occur in the solid, usually finely divided of course. 6, I think so as the loss of the deoxidant via vaporization will tend to pull the reaction in the wrong direction slowing it sufficiently (maybe - I don’t really know) for the vaporization to remove the deoxidant. 7, No, not for copper as then end product is bifilms of aluminium oxide - the bane of aluminium bronze founders. But yes, for steel as the alumina fluxes with other oxides and becomes molten then as globules of molten oxide it floats rapidly to the top of the melt and can be skimmed off Aluminium is used commercially to deoxidize steel but better deoxidisers are available for copper - see below. Re brass make up - I am no expert - I have never done it! I hate brass, in my early casting years I did do brass but started with existing brass - I did not like the zinc fumes and the colour change that occurred as the zinc content altered - candles sticks cast one day were a different colour to bases therefor cast the next - hopeless. There are simply much better alloys out there and brass has a horrible greenish colour anyway - well - compared to an Aluminium silicon bronze which is much more of a true gold colour. I intend to do a video when health permits on proper melting of copper and that is part of the secret to alloy make up but you will have to wait until then as I prefer to keep my powder dry.😏 Counters have to be cast - I had figured that as being likely but what about casting all in copper and then electroplating half with Ni or Ag or even Cr? - Even black nickel? Beware of phosphorous - too much and a very low melting eutectic is formed which penetrates sand very badly giving very rough castings. Those tubes contain 15% phosphor copper just open one up and weigh out the required amount. Wrap the required amount up in copper or brass shim stock and plunge using a forked steel rod to hold the wrapped phosphor copper to the bottom of the melt. How much to use? Good question - and it depends on how badly oxidised the copper is and that is an unknown - traps for the unwary! At a guess use at least the 1.4 gm and maybe twice that if your copper melt feed is thin or is known to be gassy. It is common for good copper work to deoxidise first with Phosphor copper and finish of with Lithium - Foseco make a lithium containing tube. Adding 5% silver improves fluidity? - Hmm, not heard of that, and it flies in the face of pure metals and eutectics being the most fluid of metals. As a general rule fluidity is known to drop off very quickly with impurity increase. In the Ag Cu system max fluidity would be likely at pure Ag or pure Cu or 28.1% copper the eutectic alloy (mp 779 deg C) Hope some of this helps My ignorance thus exposed I will see if I can dig out anything about the Ellingham diagram that I can understand - I will pass it on if I do….. Martin. PS, Now I really am out of time😱😊

Hi Martin, so kind of you to give me the time once again for such a detailed response. I'd like to thank you personally and on behalf of my subscribers for your continued sharing of your knowledge. I have emailed someone, I hope he can help with the Ellingham diagram, but I expect he is extremely busy... fingers crossed. To your answers: 1. So again, we are back to the importance of degassing the copper correctly before adding the zinc and preventing the further take up of oxygen into the melt to produce a more limited reaction from the zinc when added. 2. Am I right in my understanding you always need a more reactive ingredient to produce a reduction in oxides, the more reactive a metal is the harder it is to find a more reactive one to perform the reduction. e.g copper would require a more reactive material such as phosphorus or lithium to perform this reaction ? 4. Would boron copper be an effective way of eliminating oxygen from copper melts as well ? 7. I understand the advantages of reducing bifilms into the casting and the difficulties in not introducing them in the first place. I have seen several videos where people have specific sprue designs, spin traps and pouring basin design, all of which may help reduce them... And then I watch you produce perfect castings using none of these techniques.... I wonder of the efficacy of it all... Especially when you think of the history of metal casting through the industrial revolution with steam engines and such. I look forward to your copper melting video with great interest. Copper is my metal of choice despite the difficulties it presents, I'd love to learn the secrets of successful copper casting. I know lots of people won't touch it for casting, but there's something about it that really gets me... I have never tried electroplating, I should look at that for some future videos. Again it's something that can go hand in hand with producing more varied and interesting castings. Noted on the phosphorus, I'm struggling to find lithium copper online in the UK though, I'll keep looking - perhaps I need to phone them first. I wasn't sure on the silver content, all I know is few times I have mixed copper with silver in the past it seems to have a much better quality to it than regular copper. Porosity seems much reduced and the quality of the casting seems to have a much better finish. I have opted for a 25% silver / 75% copper mix for the counters "Shibuichi", the sheen on this alloy is just stunning and when combined with the gold leaf should look the business... Thanks again for everything, good health, best wishes Andy

I am not sure, it makes total sense to me, but referring back to Olfoundryman's earlier comment where copper and lead are insoluble I wouldn't want to stick my neck out and say for sure. If nothing else the weight of the lead would drag the zinc to the bottom of the crucible pretty quickly which would be a benefit in my opinion. I had a quick look online and found an old paper on the solubility of lead and zinc together and if I understand it correctly only suggests a 1.5 -2.5% solubility of lead in zinc but again I am not sure if I am reading the data correctly. I do think it's something to try out in future though... Olfoundryman is planning a future video on the correct melting of copper, I look forward to that with great interest as it should really help with the creation of copper based alloys. Keep an eye out for that one, and do bung him a sub, as his knowledge is second to none. Cheers Andy 😎🍺👍

@@MeltandCast Thanks for the reply and information!

I hope so... my Dad would have loved it !! Cheers 🍺😎

I did think about getting them anodised. But I think if I did that I'd feel like I'd cheated myself... it would give the best finish most likely, but it would be too easy...hehe. Cheers Andy 😎🍺🥂

Thanks Johnny 👍🍺🥂

Sounds good... gold leaf on polished copper would be a really nice combination too... I'll have to try both and see what looks best... Cheers Andy 😎🥂🍺

Hi Dan, I thought the lead inclusion would make it a lot darker, more of a brown colour. Other than copper I can't think of any alloys that are a deeper red colour hence the change in direction to liver of sulphur. There are some patinas that can be applied which give really deep reds, I haven't done much research on patinas yet but some of the heat based ones are very vivid. I'll have a go with some pieces soon. I'd like to find a red / purple patina to use on the board but i think it would need to be chemical based to prevent leeching into the other triangles and the background. Cheers Andy 👍😎🍺

Haha Thanks Ralph 😎🥂🍺

Thanks Hanely. The reaction is something I'm trying to avoid, the idea is to have as few oxides as possible in the melt. An exothermic reaction with the zinc is something I want to eliminate. Maybe you're right on the flux though, perhaps I should be stirring it into the melt and allowing it to cover the surface again before adding the alloying elements ? It is called a 'refine and cover flux' after all... It behaves like molten glass. Perhaps the black colour in the flux is charcoal which may act as a de-oxidiser with the copper ? I'm not sure to be honest... I'll have to try stirring it in and see if it makes a difference... Cheers Andy 🥂😎🍺

Cheers mate, glad you enjoyed it... Andy 🍺😎

Haha thanks Joseph. The backgammon board seems to be getting more complicated week by week, I'll stick with it though. Getting some great advice and suggestions from the community. Cheers Andy😎👍🍺

@@MeltandCast that it does, lol. Can't wait to see the finished result! :)

Thanks Pharaoh, best wishes Andy 🍺🥂

Thanks Captain, changed my mind yet again... going for Shibuichi pieces now 25% Silver / 75% Copper and inlaying them with gold leaf. Made a 12 oz silver bar yesterday... I know you like your silver... Just wanted to have one to hold before I melt it all down again haha. Cheers Andy 🍺👍😎

@@MeltandCast I felt similarly when I poured my silver skulls...