Tips for successful backyard casting of brass round stock

[@Xynudu]

Note: Next time I melt chromed brass I will pour the melt into the large mold and hold it at high temp to keep it liquid and allow the heavier metal (whatever it is) to settle/pool at the bottom. Then it should be easy to remove that layer with the saw when cooled. Should work I think. I have come to the conclusion that the heavier mystery metal may be nickel, used as a binder/intermediate layer between the brass and chrome. Cheers Rob

[@AmateurRedneckWorkshop]

I see the Xynudu smelting and foundry company is still turning out product. Keep on keeping on.

[@TheKnacklersWorkshop]

Hello Rob, Some useful tips... I must admit I always tell others to warm the molds after seeing the good results you get. Cheers. Paul,,

[@scroungasworkshop4663]

Thanks Rob, I’ll be taking that on board. I have buckets of scrap brass and number 2 copper to melt, number 1 copper goes to the scrappers. When I’m melting scrap aluminium I like to pour it into cast iron muffin pans first and then remelt what I need. I know that gets poo pood by the experts but that’s the way I prefer to do it. I also like to cast separate batches of similar material and this has revealed quite a difference in quality. I found complex heavy vehicle cast parts gave me the best “ingots” being very smooth with a beautiful even sheen and no porosity when cut where as a bucket of aluminium horse shoes were rubbish in comparison with a rough finish and some porosity when cut and more of a frosty finish to them. I guess this is due to the vast and complex mix that goes into what looks to be ordinary aluminium. I will also separate and pre-melt my brass and copper as well after watching your video. I put it down to the price of using scrap materials but it also give you the benefit of seeing how the metal will cast before potentially ruining a pour. Cheers mate, Stuart. Canberra. 👍👍👍

[@Xynudu]

Hi Stuart. Next time I melt chromed brass I will pour the melt into the large mold and hold it at high temp to keep it liquid and allow the heavier metal to settle/pool at the bottom. Then it should be easy to remove that layer with the saw when cooled. Should work I think. There certainly are enormous differences and number of types of aluminium. Brass is similar and it's all related to the copper content as far as I know. The cheap stuff being sold on Ebay/Banggood is a case in point. Try silver soldering it and it may even melt due to the high zinc (or even aluminium) content. It's happened to me if you get too agressive with the torch. Fascinating subject which is far more complex than most beginners realise. Cheers Rob

[@scroungasworkshop4663]

@@Xynudu Absolutely it is. I was originally getting all confused but the best tip I was given was to use cast aluminium scrap as that already contained the correct blend of materials to suit casting. I have access to large diesel pistons but I don’t bother and I also scrap any extruded alli and just stick to cast. Cheers

[@Xynudu]

Yes, I only use ally that has been cast and machined before. Even then, there are huge quality/consistency variations and some grey looking die cast is likely to be rubbish. I find that high stress load scrap such as alloy vehicle rims are the best option and very cheap or even free. Cheers Rob

[@shadetreemechanicracing22]

You can sand blast the chrome off. You can use hydrochloric acid (muriatic acid) solution or sodium hydroxide solution in a well ventilated area.

[@timmienorrie]

Hiya, Rob. I believe those tap cover parts to be chrome plated zamak alloy. Google will tell you all about it. It's not totally chrome as a few micron thick coating could never amount to that much metal. Of course without analysis we can never be certain but zamak is commonly used in bathroom fittings.

[@Xynudu]

OK, that's a possibility, but Zamac doesn't contain brass, which is what 80% of it was when I turned it down. Cheers Rob

[@pgs8597]

G'day Rob. I have no idea what it is either, something in the chrome that didn't fully melt I presume. Interesting exercise though. Cheers Peter

[@Xynudu]

Hi Peter, Looking at the material weight table it rules out most suggested metals by sinking to the bottom of the mold. Maybe it's Nickel ? I will know how to handle it next time, but very strange. Cheers Rob

[@andrewdolinskiatcarpathian]

Thank you Rob for all these interesting observations. Always fascinating to see you at the furnace and the lathe. 👏👏👍😀 Andrew

[@Xynudu]

It's all a learning curve Andrew. Makes life interesting. We never stop learning. Cheers Rob

[@ianlulham]

You got some very useful brass out of your scrap Rob. I imagine it is posable to cast larger diameter pieces and would only be restricted by the amount of actual scrap you have and of course the capabilities of the furnace you made. I enjoyed the making of this furnace and glad your making full use of it. Watch the fuel bills boss

[@Xynudu]

Hi Ian. The furnace is a huge success and cost very little to knock up. Certainly handy being able to stick weld. I did most of it with AC as I find that best for dodgy/scrap metal. DC is much more particular and subject to arc blow. I cut my teeth on AC and still prefer it. The burner does eat up the gas, but not at a horrific rate. That cylinder has done at least four melt sessions and will go one more, so that's about $5 AU a pop. Quite reasonable. Cheers Rob

[@ianlulham]

@@Xynudu Great you share this stuff Rob. I have an arc welder tucked away for future use but want to try TIG or wire at some stage in life..one day.

[@Xynudu]

Hi Ian. I have never actually tried MIG or TIG but seen plenty done badly. MIG only works well when used with gas and once again being DC the job must be thoroughly clean. Those cheapskate gasless MIG spools just make huge spatter from my observations. A decent AC stick unit can weld quite cleanly if done correctly. DC stick is also pretty clean, but arc blow can be a serious/frustrating issue. The slightest bit of magnetism in the steel will wreak havoc. You rarely get arc blow with AC. For thin walled jobs like gas cylinders AC can work well provided you don't linger too long in one spot. So you need to have some practical experience before attempting it. A bit of paint hides a multitude of sins, so nothing to worry about ;) Cheers Rob

[@RetroSteamTech]

Interesting stuff Rob. I never thought about it before but plumbing fittings must make a great source of brass, I'm sure that many just get thrown away. Cheers, Alan.

[@Xynudu]

Hi Alan, I had a lot of these worn out old tap fittings laying around looking useless for years and this is a great way to get more life out of them. The tap body brass is very good quality. I had reservations about the chrome plated bits and hoped it would just burn up, but I was dead wrong. The scrap man would give bugger all for them any way. Next time I will pour the melt of these bits and hold the mold at high temp to allow the heavier metal to settle to the bottom for easy removal with the saw when cooled. Should work I think. Cheers Rob

[@shawnmrfixitlee6478]

not to bad rob .. your right with more heat and hold it there for a bit..

[@Xynudu]

Hi Shawn. I think it may be the answer. I'm also thinking the mystery metal may be nickel, used as a bonding agent between the brass and chrome layers. I do know they do similar when electroplating some materials. Cheers Rob

[@shawnmrfixitlee6478]

@@Xynudu That sound very possible Rob..

[@MiniLuv-1984]

I reckon that was zinc at the bottom. Chromium has a melting point of over 1900 oC, zinc around 450 oC, while brass is around 950 oC, so I reckon the zinc melted and separated from the molten brass due to its weight. I'm no metallurgist, and I'm sure its far more complex than I imagine but basics are basics.

[@Xynudu]

Good point Benny. I thought being thin the chrome may burn up, but it's more likely to separate as a solid. Looking at the metal weight table it indicates brass and copper are heavier than zinc and chrome, so that doesn't gel with what happened. I'm a bit puzzled by all this. Next time I melt chromed brass I will pour the melt into the large mold and hold it at high temp to keep it liquid and allow the heavier metal (whatever it is) to settle/pool at the bottom. Then it should be easy to remove that layer with the saw when cooled. Should work I think. Cheers Rob

[@MiniLuv-1984]

@@Xynudu Sounds like a plan. I am puzzled too...could it be lead - perhaps leaded copper? I found a comment in a researchgate forum where melting the leaded copper resulted in a separation of the two metals due to differences in specific gravity. I look forward to any other info you may uncover Rob! Then the other titbit: "crystalline like structure that broke off by tapping"...not making much sense! That chunk you cut off - can you scrape it easily - is it soft like lead?

[@Xynudu]

I'm wondering if it's Nickel and was used as a binder/base layer between the brass and chrome. That's the only metal that fits the weight table variations by being heaviest. Cheers Rob

[@MiniLuv-1984]

@@Xynudu That sounds plausible - it looked like 10% of the rod was that material - you reckon there would be that much nickel required for plating? Rob, the plot thickens!

[@Xynudu]

I'm not an electroplater Benny, but I do know they use multiple elements in layers on some electro plating jobs. Given the original brass tap plates were pretty thin, the percentage of chrome and bonding elements would be proportionally high, so 10% could be around the mark. Anyway I've used up all my old chrome tap fittings for now, so it's time to move on. Cheers Rob

[@thehobbymachinistnz]

Hi Rob, another good video and thanks for sharing your knowledge and findings. I will need to do this soon as I have no solid brass left for projects. But, I do have a lot of brass fittings that I can melt down. When you let it cool down slowly, is it easier to get out of the mold than aluminum?

[@Xynudu]

No, it has a lower expansion rate and can be hard to knock out. A press would be useful. It comes out more easily if you don't overheat the mold (to red hot). Cheers Rob

[@sam222me5]

Hi Rob Thank you for your efforts, please keep up the good work It would be interesting to see the actual properties of these home cast materials, if anybody has access to suitable machinery and equipment to do metalurgical tests I have been casting my own aluminium, brass and copper for a few years now and have used it for many things, without any problems, its just that I never know what grade it is, or even close too. When I have melted a mix of brass scrap of unknown grades, my end result is also unknown I would not use homecast for anything safety critical, but I never know how good or bad it is I have cast copper inserts from household water pipes for mallets and used them vigorously and they have behaved just like genuine ones I have made brass engineers hammers out of plumbing fittings, again with no problems I always try to separate my metal before I melt it, into groups and write on the cast bar what it was made from "aluminium ladders" "car wheel" or "burnt out car" are common ones I use steel molds for my casting of general barstock shapes and blocks and had to thrash the cast item out of the mold, but never managed to break any I use extruded aluminium for casting and other than a bit more shrinkage, claggy machining and difficulty in getting a shiny finish, they have all been perfectly usable for non critical parts It would be intersting to see someone do some serious testing of homecast materials Thanks Sam

[@Xynudu]

Hi Sam, have you ever seen this mystery metal result before ? I was quite surprised. It has strange characteristics. Looking at the metal mass tables it's also strange that it sank to the bottom of the mold as that rules out most likely suggested metals, except one "Nickel", but how that fits into the equation I can't say. I think I can do a work around by keeping it liquid in the mold to settle out for a while. I'm out of plated fittings now so it may take a while to try. Cheers Rob

[@MyHeap]

Hi Rob. Great information you just shared with us. Thank you. Have you sand cast any of your brass yet? Joe

[@Xynudu]

Hi Joe. Yes I did a brass fitting in sand and ATF mix. Came out excellent. That was the work piece I destroyed in my classic stuff up video : kzbin.info/www/bejne/b5LGhqOEZ7yliZY Cheers Rob

[@iancraig1951]

I would be more than happy to use brass like that Rob---it looks excellent.... Question--have you tried using any of it for bearing bushing---wearing etc.. regards E

[@Xynudu]

Hi Ian. I have used it for small close fitting pistons in air/steam engines without any issues. It seems to machine with similar characteristics to good quality bought brass and my metal bandsaw has a hard time cutting it, so it is quite hard. Cheers Rob

[@iancraig1951]

@@Xynudu Thats good to know Rob---you can rely on a product thats good..

[@CraigLYoung]

Thanks for sharing 👍

[@charleskutrufis9612]

Hi, How did you get the pour out of the mold after it cooled?

[@Xynudu]

Knocked out with a punch as the difference in expansion rates loosens the plug slightly.

[@dcraft1234]

Ever melt down cartridge brass? I have a lot of that.

[@Xynudu]

No.

[@ludditeneaderthal]

The brittleness makes me think zinc (it's hard and brittle). Soaking in a medium concentration acid solution (like battery acid, vinegar boiled to 1/4 volume, even just a box of tartaric acid (cream of tartar) dissolved in a liter of water will tell... zinc will be etched quite obviously. You'll probably find it's zinc and chrome

[@Xynudu]

It's an interesting one for sure. Probably be worth pouring it into the larger mold next time and hold the heat at red hot for a while to allow all the heavier metal to pool at the bottom for easy removal with the saw. To try and remove the chrome before melting would be difficult I think. Cheers Rob

[@ludditeneaderthal]

@@Xynudu agree 100%. Stripping chrome would be a pain. If you have enough of the escutcheon plates to warrant it (or similarly plated parts), maybe an even larger "precipitation mold" just to produce clean raw alloy for remelt.