Great idea Russell. Smaller diameter stuff is the hardest to cast as it's difficult to find a uniform diameter tube in those sizes. I will give that a go next time I get some old shocks. Thanks for the tip. Cheers Rob
Love the video. I will be trying this when things return to normal and I can get some wheels. Warning- Long boring story approaching.... Back in the 90's I worked in a workshop that had a furnace and die casting machine that made various small alloy parts. It ran about 2 or 3 days a month, whenever we ran low on parts. Like you the molds were put on top of the furnace to heat them up before fitting to the machine, when ready to start pouring. We bought alloy in large ingots that were also pre heated around the furnace mouth (wish I had just one of those ingots in my shed now 😊 ). Molten alloy was ladled out of the crucible and hand poured into the mold. Standing beside the furnace it was 50 to 55c summer or winter, and the shift ran around 10 hours. Can you say hot? This was country Victoria so OH&S was non existent. So MY personal choice of safety gear ran to gloves, sandals, shorts, T shirt, sunglasses, and ear protection (the gas furnace was LOUD). But as they say "don't try this at home." Lol Any "mistake" with molten metal will hurt like hell. I was always very careful and in 10 years zero injuries.
It's all as dangerous as you make it. Sounds a bit on the hot side to me, but then again, if no one got injured then the system must have been working OK. This is one of the reasons man invented beer ;) Cheers Rob
I worked in a big aluminum foundry years ago and learned a fair bit. I think for molds I'm going to get some different sized heavy wall pipe, cut the seam out then hone the inside with an engine cylinder hone for a decent finish.
stop by any decent size machine shop or shop specializing in hydraulics and you can get end cuts or scrapped honed cylinder tubing for next to nothing. I throw tubing that is scored in areas but good in others away all the time.
You are absolutely right about treadmills. I used to put an ad on Craigslist looking for old/broken treadmills that I would pick up and haul off for free. People are always trying to get rid of them and they are so bulky and a pain in the ass that most people thank you to get them out of their house. You can use every part of them for something.
I did quite a bit of this at one time, up to 4" X 10" long once (that was hard to get out of the pipe!). I found the top 1" or so was much softer than the rest and would cut that off and throw back in the scrap pile.
Hi Crichton, I only cast the length shown, as I tried twice as long and it wasn't as uniform (as you say). Most times this is more than long enough and the bit in the chuck jaws usually gets re-melted as well. Cheers Rob
I always watch that guy "BigstackD" and wounder if any of his ingots are any good for matching. I would love to have some of his stock if it's any good.
Scrap yards will often have broken alloy rims, so you pay around twice the scrap price there, and look for the most chewed up and broken ones, as they might just give it to you for scrap price anyway. My local scrappie is my preferred place to get metal, lot cheaper than buying it newe, just get it as second hand instead.
Fortunate to have several metal suppliers nearby, I go there and dive into the remnants bins for aluminum & steel. Brass is valuable enough they don't discount remnants. Much cheaper buying remnants and all the pieces are typically just right for mini-mill projects.
The new metal (and plastic) suppliers in South Oz charge full price regardless of whether it's an off cut. The only thing you save on is cutting, as it has already happened. Very few scrap metal centres will also re-sell metal as you must have a secondhand dealers licence to do so here. They basically force you to buy new. So every time I cast my own aluminium it's a win for the little guy, and those rip off merchants miss out :) Cheers Rob
In Australia we use LPG, but propane and butane have almost identical properties and the equipment is interchangeable. No difference really. I don't set any gas pressure, just turn on the tap full bore.
Hi Rob good video as usual, you said butane but the gas bottle in the background looked like LPG ie propane. Is the bottle pictured near the end of your video the gas bottle you are using for heating the furnace?
Hi Rob, A nice masterclass there.... One question, after warming the mold you put it in the tin can on another piece of steel (i am assuming it was steel). Would i be correct in thinking it was sand in the bottom of the tin can? Take care Paul,,
Hi Paul, Yes, sand is a good idea as it contains any leakage and insulates as well. You can stand the cylinder directly on the sand, no problem. I use the steel plate to get a flat end. Cheers Rob
On using sand: yes, I made a furnace the same as Rob’s (thanks Rob!!) which works well. However, I put a layer of sand about 5mm thick on the bottom as it greatly protects the degradation of the internal can at the bottom of the furnace due to heat. Sand has a melting point about 3x that of aluminium so works well.
Great tips Rob. I would not have guessed you could set a tube on top of a plate for the mold and not have it all run out. As I'm sure you've heard, many say never to perform casting operations over concrete. They say you get an explosive reaction if the molten metal touches the concrete. What's your response to that?
Hi Rick, yes that's dead right. All cement has moisture in it, which instantly turns to steam on contact with hot alloy. The pressure forces the cement apart (into splinters) which then sprays the molten metal around. It happened to me once when a crappy crucible leaked. Plus there's nothing to stop the alloy running all over the place. A sand bed prevents all that. I always pour over a sand filled container and try and do it outdoors over soil, if the weather permits. Always wear a face shield when pouring. Cheers Rob
@@Xynudu Thanks Rob. Quick follow-up: I have some good stainless tubing. Any problem with using stainless for molds and/or crucibles? I know certain metals give off toxic fumes.
Hi Rick, stainless steel tubing usually has a seam (the stuff I've used did) and that is no good. Being thin walled it is also less likely to be perfectly round. You can only try what you've got and see, if it is uniform internally. Run some dividers through it. Stainless steel contains Chrome and does give off toxic fumes when welded. I personally wouldn't use it for a crucible even though I have some which is suitable diameter. Stay with mild steel (heavy pipe or electric motor casing with a welded in base, or something similar) and it will be safe. Cheers Rob
Hi again Rick, regarding the tube seal on a metal plate - that only works if everything is dead flat. Even then you may get a tiny bit ooze out. It knocks off easily before removing the tube center. You can put a sand seal around both if you want to prevent it. Cheers Rob
Hey Rob Kevin here from Melbourne. I love these videos. I rekin making a crucible out of an old gas bottle would make for a great series. Q. Have you ever thought of putting in a wood heater in your workshop having heat just changes everything. Anyhoo stay safe and stay well. ✌ Peace Rob.
I see you were doing it in side your shop, how dangerous would it be if you were melting drink cans with the fumes from the plastic getting into the air? Like you said start with good aluminium but that is not always the case. Also it looks like a lot of fun and satisfaction however how much does it cost in gas?
Hi Tony, I have never melted drink cans as I don't buy them. It pays to have adequate ventilation as plastic fumes are usually toxic. At a rough guess I used about $1 AU of gas (ten minutes heating time). Cheers Rob
Have you ever tried to melt brass or bronze in your foundry or doesn't it get hot enough? I built one with perlite and cement just like you but used a steel 5 gallon pail. I also made my own burner setup using a copper .035" mig nozzle contact tip and an off the shelf regulator. I never tried brass or bronze in mine, that's why I was asking. Thank you sir, I hope you have been doing well.
@@Xynudu Thanks for the reply! Such a simple setup. I was watching a video yesterday where the parts to make a furnace were around $500 alone. Not to mention extra stuff that was recommended. I think I'll develop a similar system to yours and give it a crack before spending too much money. Love your work and the knowledge you are passing on. Cheers.
Hey Rob, I also cast my own aluminium using the exact same method... Doesn’t work with brass or copper unfortunately :(. FYI that I recently started artificially aging my aluminium castings and the machinability gets much better... not that it was terrible. Give it a go. This video is a good example... ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-z5ejhb1t8BY.html
Well I was working in what I consider to be the minimum space John, but normally I would do this outside. It is winter here and it was raining, so that wasn't an option. Plan out your movements and area requirements, have everything in place and at hand, and you should be fine. Accidents happen when you try to improvise on the go. That's just not an option with this sort of activity. Cheers Rob
I'm a state to the east, for reference recently I paid about $15 for a 6" long bit of round, about 2 1/4" diameter. This particular fella will cut and sell you any length which is rare.
Hi Rob,. I sure want to do this in the future and have enjoyed the videos along the way. You mentioned using a butane torch but looked like a propane tank that you were using. Just wondering? Dale in Canada
In Australia we use LPG, but propane and butane have almost identical properties and the equipment is interchangeable. No difference really. Cheers Rob
Thanks for that. In Canada we still call them 20 pound propane tanks. Even though we are supposed to be metric now some things are hard to change. It was in the 70's when we switched. Still hear grumbling about it.
In the UK after the 2nd world war the British Government introduced a scheme of free milk for children in schools. All the bottles came with a sliver aluminium top. My task as a student was to collect all the tops and wash them, then the metalwork teacher would melt them down into billets. We would then make turbine housings for steam turbines. Great fun and and free Aluminium.
We had those when I was a kid going to primary school. The bottles always had about 3/4" of cream on top of the milk. I don't particularly like milk, so that got turfed.
@@Xynudu Yes, I was a little surprised to see the made in Taiwan casting on mine, I installed a larger base plate for hand sawing awkward sized pieces. In 18 years I'm on my second blade.
Hi Angelina, I have broken two blades in about the same period. I upped the motor to 1 HP and it definitely won't slow down now. Saves a LOT of hard sawing work. Cheers Rob
Alan at Retro Steam Tech followed my lead and made a similar furnace out of a small UK style 5 litre beer keg. Worked well and now he's hooked. So check out how he did it here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-vYXWm1WnpLo.html This is dead easy, but play safe. Cheers Rob
How about aluminium pistons? There is an engine rebuild/recondition place near me. I guess I could get plenty of pistons. Is that as good as wheel rims?
Porosity (and shrinkage) from dissolved gases was always my nemesis. If I needed/wanted a central hole, it was fine. But for a solid block of turning stock, multi g my own was crap! Was better off taking scrap into town and trading for bar stock.
Hi John, that was probably 1/2 kg in the video and I used 10 minutes worth of gas, so at a rough guess it would work out about $1- 2 AU per kilo. Cheers Rob
Good video,Rob. I have cast lots of ally billets in the past for bar stock. Agree with you on some of the myths that are circulated our there. Some folk seem to have a need to turn things into black arts when there is no justification for doing so. As you say,if you start with good quality melt stock you will end up with good quality billets. Just to add that this ally melting procedure can be carried out very successfully using only barbeque charcoal in a steel cylinder with a moderate forced draught. I can never figure out how some suppliers justify the astronomical prices they ask for ally and brass stock. Me thinks they're extracting the piss in large quantities.
Hi Howard, in dry weather I use an outside wood furnace with an air blower. Works well and is cheaper than using the gas fired rig. It is also able to do larger volumes at once. I've used charcoal in it at times. Adding an air blast to any fire increases heat output by about 400%. Cheers Rob
ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-vcp6MtfjZDk.html I originally used a hair dryer, but you can use a vacuum cleaner that blows or a kids bouncy castle blower. It has to be capable of blowing at reasonable pressure. That aircon blower might work. Try it and see. You can't add air to gas powered furnaces very well as they are usually jetted lean to the optimum temperature. Adding extra air usually just makes a lot of noise or blows it out. Cheers Rob
That is a very old video and I was doing what I read on forums at that stage, but after many years of home casting you realise that a lot of it is BS. I no longer use a degassing agent or a flux. If you do what I tell you in this video you will get a good result. End of story.
Hi Ted, you can try, but generally you will get a lot of dross and not much usable alloy. The problem is that turnings have a massive surface area, and as a result they also have a massive oxide coating. This is bad news when melting as all that oxide forms dross. Good luck though. Cheers Rob
Back in the 80's I was Maintenance Manager/Manufacturing Engineer for UTC's aluminum extrusion plant in Coldwater, MI. We generated a great deal of chips from cutoff and machining processes. The dross loss was huge from trying to melt the chips. We sold them to others that were willing to put up with the poor return. One of the guys who worked for North American Burner Company came up with an idea to reclaim the metal from the chips. He built a prototype and it worked well. He faced several problems. The chips usually had cutting fluid or oil on them and they had to be dried before being introduced into the molten bath. Any water would be immediately stripped of one oxygen atom by the molten aluminum and the resulting hydrogen peroxide along with the steam from the boiling water would explode. The presense of free oxygen in the atmosphere would cause the chips to rapidly oxidize. Aluminum Oxide is a great abrasive but is very difficult to break down into free aluminum. His basic design was to have the chips in a loading chute that acted as the flue for the melting furnace. The burner in the furnace was set to create a reducing atmosphere. The heat would travel up the flue and dry the chips as they entered the flue. The reducing atmosphere prevented the chips from oxidizing as they achieved melting temperature at the entrance to the furnace. It was a successful process but any deviation from the normal operation, overly wet chips, air leaks in the body of the furnace or flue, would cause the chips to burn or enter the melting chamber with water still in the mix. The plant was destroyed when a load of mixed magnesium and aluminum chips were accidentally loaded in the furnace. The flue was burned and the furnace was destroyed by the resulting over heating. There was another attempt to create heat without open flame in the melting process. The Jumping Ring aluminum pump was proposed as a addition to the charging well of reverberatory aluminum furnaces. The premise was to stir the molten metal in the charging well using electromagnetic force per Lenz Law. The concept was to introduce the chips or any scrap material into the melting well. The molten aluminum would heat the scrap and the pump would circulate the scrap into and under the surface of the bath. Wet chips were not well received. Also the jumping ring was immersed in 1100 degree molten metal. To maintain operation the coil had to be water cooled. Failures of the coils soon knocked the immersed style jumping ring out of the market. I checked to see if the immersed jumping ring was still in use. (I found no evidence of that to be true.) While doing the research I found Pyrotek is promoting a type of electromagnetic metal pumping system. I have no idea if it works or is another flash in the pan so to speak. www.pyrotek.com/primary-solutions/aluminium/casthouse/metal-transfer-casthouse/molten-metal-pumps/show/ProductLine/electromagnetic-pump-emp-systems All that is to warn you that messing with chips has been a recurring theme in the remelting scrap aluminum business for at least 40 years that I am aware of. Play with it if you wish. Remember that the forces involved are high. The resulting explosion of aluminum processing plants has killed many a poor soul who thought they had the solution.
@@OldSneelock The company I worked for until retirement also had a plant that did extrusions in Coldwater Mi. During my tenure with that company I working out of its sister plant in Cleveland, Ohio, and made many of those long boring drives to the Coldwater Plant. The Company was Amax Specialty Metals/Climax Specialty Metals /CSM Industries plus several other names over the years that I don't remember, it was located on Jay Street.
A mate of mine used to smelt his own aluminium bar stock. He once bollocked me to high heaven because I used the wrong vacuum cleaner to clean off his mill off after I was using it (I thought I was being polite by tidying up after myself !?!?). Turned out he had 2 identical vacuums, But one had a little label that said "ALUMINIUM" on it....... Yeah, The cheapskate even had a dedicated vacuum for cleaning up aluminium swarf to keep it separate, so he could re smelt that as well !!!! :D
He must be a real cheapskate. It's a bad idea to melt swarf due to the massive surface area. It has a similarly massive oxide layer and consequently makes lots of dross with very little usable alloy. Mine all goes in the trash can. Cheers Rob
@@Xynudu I think his reasoning for using it was something to do with it melting quickly and forming a puddle that helped transfer heat from the crucible and into the little ingots he'd melt. I was only in his workshop once while he was melting metal down, and I was busy with my own thing at the time, so I may have missed some other info on why he was using it. I mainly just remember getting my head chewed off for using the "Aluminium" vacuum cleaner to hoover up all the steel chips I'd created.