Відео

Phylis, The large round base plate is mild steel, all other parts of this die are grey cast iron machined from continuously cast bar....Martin

@@olfoundryman8418 you mean I can machine my own aluminum dies from cast iron! Amazing. Just saved me lots of money. Im trying to cast some pulleys (10 inch/25 cm diameter) out of aluminum and I'm honestly very new to casting anything. This would be of great help. Thanks so much, Martin

Phylis, Yes, you can use grey cast iron to make dies from. In fact it is a rather superior material as it has higher thermal conductivity than most steels and it tends to have a little "roughness" due to the presence of graphite in its microstructure. The graphite being very soft eats out a little and the resulting slightly uneven/rough surface provides excellent keying for the die coats that need to be sprayed on the hot die. Good luck .... Martin

andrea, I enjoy sharing and Iam glad that you liked it.... Martin

dieter, I am very glad to have been of assistance.... Martin

@@olfoundryman8418 Thanks again Martin.I was casting arms for my drone.they normally made from carbon fibre and break when you crash but aluminum is more durable.It worked great! Now I am excited about casting.I want to make myself more permanent mold.I was looking at using refractory cement to make a mold.Would the process be the same as making a sit sand mold with a fairly dry mix?

Greg, Thanks for your comment. You are not the first person to have wished to have seen the actual castings, They can be seen in the fifth video in this series;- see here ua-cam.com/video/Lcvew9Wo3Vk/v-deo.html Those with this basin and sprue can be seen being poured from 7.00 on, and the resulting castings are broken out and viewed towards the end of this fifth video. Hope this provides you with what you wish to see.... Martin

Kevin, I wonder which books. Many out there just regurgitate the same old - and largely incorrect - 6000 year old info. I have yet to see a good book on all aspects of casting and I have seen a few. For the technical side the work of John Campbell can not be beaten but he does not cover the nitty gritty of things like mould making and many books that do make an absolute pigs rear of this vital aspect - nobody covers it well - not well enough anyway..... Martin

Peter, Glad that you liked it.... Martin

Scotts. Yes this method will work for silver - it will work form all the metals we are ever likely have to deal with..... Martin PS, silver probably only appears to solidify quickly because the pieces are small ( who can afford to cast a silver piece weighing in at a few kilos? and small pieces in any metal do solidify quickly as their surface area to volume ration is so big.... Martin

Mike, In return, I just love viewers like you..... Martin

Mark, Sharing is my pleasure... Martin

Fans, Yes, you are right but sadly very sadly we need cheap energy to be able to manufacture locally and we all know where our energy prices are going - I weep at every electricity bill. I remember when Nissan set up a casting plant in Dandenong why here in Australia, one reason, cheap electricity back then. We are slipping ever further into the dig it up from or grow it on the ground and sell it cheaply overseas banana republic status.....Martin

@@olfoundryman8418 seems as if greed is killing everything!

paul, I don't see why not, providing of course that the masters are coated with a suitable die spray - a graphite based spray would be suitable. The masters could also be steel. I have used steel masters for aluminium dies but have never tried casting a die out of bronze this way. However I have made dies for aluminium castings out of bronze by sand casting the die to an approximate shape and then machining to refine. I did find that bronze/brass dies tend to be attacked by the aluminium being cast in areas where the metal impact is high.....Martin

@@olfoundryman8418 Thanks for your reply sir. Let me try I have been using Aluminium but this time the weight of the castings is a bit higher I think which make the die to overheat and loose dimensions.

jack. The rotating rods break up any lumps in the sand, mix it all properly, and aerate it so it sort of fluffs up and makes it feel as close to silky as its possible for sand to feel. After passing through this machine the sand rams much better and makes a better stronger mould.....Martin

vwk, The methods I show here are certainly a good start and Iam glad to have been of help.... Martin

that, I am glad that you liked it. It is particularly (but not only) those involved in the trade that I would like to show this relatively new knowledge to. I am grateful to those who did the research and practical work that led to my discovery of it. In particular the work of Pr. John Campbell has proven to be a real breath of fresh air into the foundry industry. I suggest that you try to get your hands on some of his books and read them - they're real eyeopeners....Martin

Todd, Years ago, I used hexachloroethane tablets to try and degas my aluminium. Not having a Reduced pressure test apparatus, I cannot really be sure how well they degassed my metal. I never got any complaints about gas levels though, but then gas is hard to see even in well machined castings as the machining tends to flow metal overt the small gas bubbles and true gas bubbles are indeed small - usually below 0.5 mm. I do feel that the hexachloroethane did a pretty good job of floating oxides etc to the surface. It also did a pretty good job of rotting my tin roof which now leaks. Note that I did not use the traditional bell shaped plunger as these hold the purge gas back until it forms large (read “useless”) bubbles. You can no longer get these tablets as they posed a threat to the ozone layer, well not here in Australia anyway. The tablets that you are referring too are I guess the ones that liberate nitrogen gas when plunged. I was forced to use these when the hexa was phased out and I have to say that I was not impressed. The first problem was that they bubbled so viciously that they threw 50 mm of metal out of my A25 crucible and all over the inside of my furnace. I used to put a high steel ring on the top of the crucible to catch this ejected metal and direct it back into the crucible. This sort of turbulence is very bad as it generates oxide which winds up in the metal as thin films and it exposes metal to the atmosphere and its attendant water (humidity) thus it generates hydrogen in the metal - likely more that it removes??? The second problem was that the tablets only produce nitrogen for a few minutes (2-4) and not long enough to properly remove any hydrogen in the metal - this meant doing it at least twice. Another foundry much bigger than mine did some tests comparing these tablets with argon gas bubbling from a porous Silicon carbide hockey stick type lance. They claimed that their tests showed that not only was the hockey stick better at removing gas but the nitrogen tablets actually made gas levels worse if used once the hockey stick had done its job. I have no reason to doubt their results. This was at least 10 years ago and its why I developed my own argon lance. Somehow, I doubt that the nitrogen tablets have got any better and that it is likely that they just make the foundryman feel good rather than actually do any useful degassing. The manufacturers of said tablets would no doubt disagree 😊. I think that I still have some of these tablets sitting here so if you wish to try them and you live close call in and I will give you some - just need to check that I did not throw them out though. I would doubt that the tablets currently available are any different to the ones I tried. Note that I have done some mods to the lance shown in this video and I really should do an update but health currently prevents…. Martin

Rufus, The size of sprue former I used here was 8 mm diameter at its exit (bottom) and 13 mm diameter at its top 100 mm up. this gives a taper of a little over 1.4 degrees per side. I use this former for most of my casting work and that would castings in aluminium from about 0.2 Kg to 2 Kg. The runner bar should really have the same cross-sectional area as the sprue base or perhaps a little more. Gate area should be 2 to 3 times this depending on the mould height which on my case is usually between 80 and 110 mm. For smaller work I have a sprue that has an exit diameter of 6 mm and for larger work or where a very quick fill is required a sprue of 10 mm exit diameter. I have tried a sprue with an exit diameter of 12 mm but it passes metal so quickly that keeping even a big pouring basin full is very difficult. If the basin does not run full for the entire pour air will be sucked in much to the detriment of producing good castings. Note that all my sprue formers are round, this dates from when I first got a lathe and was able to turn these tapered sprue formers. A better shape for a sprue is like a slot as it is easier to blend it to a horizontal runner and it also has slightly more friction which helps to slow metal velocity. Keeping the same cross sectional area this would give a sprue exit size of 10 mm * 5 mm .The idea being to radius this to a runner of 10 mm width and perhaps 6 mm depth. The gates, coming probably off the top of the runner, would have a total area of 100 to 150 sq mm. Spin traps are quite a good idea IF DONE PROPERLY. The need for them increases with increasing sprue height i.e. with increasing metal velocity. I have not tended to use spin traps as by the time I learnt of them the bulk of my casting career was at an end, also with the sort of low mould heights I work with metal velocities are relatively low and the need for things like spin traps diminishes - but it does not vanish and were I still casting I would definitely make use of them - do note however, that they can be difficult to fit in..... Martin

Walter, Thank you for your loverly comment. I too watch way too many YT videos - and my wife keeps telling me so 😊Waste of time she says. But I too sub to very few. I suppose I should at least sub to more of those I watch regularly but they all seem to have so many subs that one more would not help much. I guess I am more than a little jealous of their success! Sadly, my health makes it very hard to make new videos. I still intend to try as I have many, many ideas that need showing. But years of shoveling sand and humping moulds around has destroyed my back and even just standing up is now an exercise in how much pain can one bear - old age is a crock of crap!.......Martin

Pirate, Thank you for saying so. I just wish that I was well enough to put out more videos like this. I have a lot more in mind but doing them is for me all but impossible....Martin

Walter, Well, no it would not create any more downward pressure. That is determined by the height of metal in the feeder and has nothing to do with its shape. Its the volume to surface area ratio of a feeder that is important as this is what determines how long it will stay liquid for. That said many of my feeders do have quite a sharp taper for the bottom 1/4 or so - I do this for feeders positioned on top of a casting as it is one way of ensuring that there is no hot spot (and associated shrinkage) where the feeder attaches to the casting. However all that said a slight taper on a feeder is useful as it makes withdrawing the feeder former from the mould easier....Martin

Cris, The exothermic I put on the feeder tops is called "Ferrux NF" it is made by "Foseco" although I believe it goes by slightly different names depending on which country you are in. Its basically just an exothermic formulated for use on non ferrous metals. Its job is to catch fire and generate a lot of heat, this helps to keep the feeders liquid for longer so they are better able to provide feed for the solidifying casting underneath. My advice is to start small and simple - do something simple first and work up to the more complicated parts. I am unsure what a "drum lug" looks like but perhaps try just one or two at first. You could send me a photo via olfoundryman@gmail.com and may be Ican be a bit more specific as to how you might cast them....Martin

Sirkay, Comments at any time are good! Advice to someone just starting out - boy - that's one big question. I shamelessly suggest that you watch all of my videos. Look closely at what I do and ask yourself why I do it and why I do it that way - if you don't know the answer to those questions then ask me that's what Iam here for. Be very wary of most YT casting videos, even those by long term producers of casting videos - most of these people make the most horrendous mistakes. I watched the most recent casting video by one of these people and I was horrified - in 14 plus years of practice he has learnt nothing and still persists in using the most appalling methods. Similarly be wary of most of the older casting books out there as they tend to stick to the "6000 year old technology" that is know to be very wrong. See if you can find some of John Campbell's books. This video of his is well worth watching ua-cam.com/video/9_w3OZ2b02A/v-deo.html&pp=ygUWSm9obiBDYW1wYmVsbCBDYXN0IGNvbg%3D%3D .... Martin

@@olfoundryman8418 Thank you so much for your time and advice. I have so many questions and I really appreciate the dedication to helping people and the advice you give. I see a lot of people poking air holes in their casts around the pattern, but I noticed that's not something you do. I assume its one of those mistakes people make but I'd love to know why its not needed if it is a mistake You said in a different video that you melted your metal just hot enough to melt but didn't go any higher than that. Is that a standard thing you do, and is there such a thing as melting your metal too hot? What safety equipment and practices do you recommend? Are you able to sand cast things that have curves such a bowl or mask? The curvature of it seems extremely difficult to make a working cast of. Is it possible to make the holes for your riser and spruce after you've packed the sand in and removed your pattern rather than making them during that packing process? And lastly, how do you care for your crucible long term? I see a lot of talk about tempering or seasoning your crucible, but I'm not sure if it's actually helpful. And how do you clean your crucibles?

@@sirkay9 Let’s see if can answer some of those questions: - 1, “Hole in the casts around the pattern.” This is to let mould gases escape easily through the mould rather than blow back through the metal. The gases are mainly steam generated from the water in the mould. The idea is to use a thin stiff wire to poke holes too just shy of the pattern and to do this particularly in areas of the mould where much metal is in contact with the sand so that more of the gases might be produced by the greater heat in that area. It certainly is not a mistake but I do think that many on YT overdo it and often do not need to do it at all as the sands they are using are on the coarse side and thus have high permeability and are naturally venting. I do use venting like this quite a lot and I am surprised that you have not noticed me doing it. I tend to do it around feeders for example as I have found the area around the base of the feeder (where it joins the casting) can have quite high gas evolution and if not vented the gas can bubble up through the metal mould interface - this can make a bit of a mess of a casting. I remember a job that was a 200* 250 mm plate and had 8 large fins running in the 250 direction on its underside. There was a lot of draft on the fins so they were easy to mould but the wedge of sand between each fin got so hot that the gasses blew right through the metal and made a dreadful mess of the casting. So, I used about 80 vents between the fins - problem solved - and several beautiful castings produced. My sand is rather fine and therefore of low permeability so venting is often needed. 2, “Metal just hot enough to melt” Well, No! some super heat above the actual melting point - or more accurately above the top of the melting range - is necessary to make sure the metal does not solidify before the mould is properly filled. The amount of super heat needed depends on the alloy being cast and how thin/extensive the casting is. However, hydrogen gas pickup by molten aluminium alloys increases rapidly above about 760 Deg C so one should avoid going any hotter that that if possible. Some alloys -piston alloys for example - need to be cast with as little super heat as possible. 3. “Bowl or mask” Sand casting is the most versatile casting process there is. Providing the moulder is of sufficient skill there is little limit to what can be cast. All sports of curved and bowl shapes are quite possible with practice. It just depends on how the mould is rammed up. 4, “Crucible care.” Another often over done area! It seems to be just an excuse to make a video. I have never tempered/seasoned a crucible. Mind you I do buy good quality crucibles - no fleabay rubbish. It is said that crucibles can absorb moisture from the air if left on the shelf for a while so it might be a reasonable idea to put them in and oven sat around 200 Deg C for a hour or two if you haven’t used it for a while! I did this once, weighing the crucible before and after and no weight loss so I assume it hadn’t absorbed any water anyway. 5, “Crucible cleaning” With aluminium alloys this is usually quite easy. I do not scrape the crucible out. I just let it cool down and just before the next use pull the skin of remnant aluminium out of the crucible - it usually comes away very easily. NOTE - I throw this skin away. The bronze alloys I use all contain some aluminium and again I can usually just pull the skin out. Brass is a bit more difficult particular if fluxes have been used as these tend to be sticky and can leave a lot of gunk stuck to the crucible, in this case its probably best to scrape it out while the crucible is still hot from just having been used. Note that commercial fluxes used on aluminium alloys do not leave/make a sticky product. Opps almost forgot safety - I am probably not the best person to ask about this as I am a bit careless 😊 However, always wear safety glasses. Have all skin covered - radiant heat is nasty. Make sure that all clothing warn higher on the body overhangs clothing warn lower on the body thus there is no gap that metal can easily fall into -with luck any spill or splash onto your clothing will just fall off to the floor. All clothing to be natural fibers. Leather shoes that can be removed easily and quickly. Do NOT dress up in a mood suit that restricts your vision or movement. Just my ideas and minimums at that. Hope this helps…. Martin

@@olfoundryman8418 thank you so much the answers have been extremely helpful. I'm planning on picking up some of John Campbell's books and continue to learn as I go!

Hey olfoundryman, me again. I had another question that's really been a sticking point for me that im having trouble getting through and wanted some advice. I'm having trouble getting my patterns out of the mould and its been probably the most disheartening part of learning so far. The patterns I've picked to start learning with I'm realizing haven't been the easiest but they've shown a glaring issue with my understanding of how to do the sand casting part. If there's ever some kind of an uneven slope or lip of some kind, sand end up getting around it and when I pull the pattern out the packed sand ends up taking more sand with it and totally ruining the mould (its hard to show without pictures of what I've been using so hopefully that makes sense). I've also run into the issue that because the patterns im using aren't 3D printed, there's no easy way to get the patterns out of the sand as there's no easy built in way to grip the pattern. If you have an email or something I could keep in contact with to show pictures that'd be extremely hopeful. Thank you so much for all your time

danish, Yes, I do have a video of sand casting frangible couplings, see here ua-cam.com/video/1L1RDNTR2n8/v-deo.html Martin

Chi, Yes, I would just scale down on the sprue size. The one I used here was 8 mm diameter at the bottom and I have one that is just 6 mm diameter at the bottom and for small work that is what I would use. Don't make the pouring basin to small or in particular too shallow - you need a reasonable target to aim at... Martin

@@olfoundryman8418 Thank you so much for the response! I look forward to putting your knowledge into action 👍.

email, Thank you for saying so..... Martin

Old, I am glad that the info was useful. Sharing is my pleasure.... Martin

rtert. Are you telling me to stop making videos or are you asking why there have not been more?.... Martin

Heil. Unfortunately my health is no longer good enough for me to make such a demanding video. however Luckygen 1001 has a few videos on building the sort of furnace that he uses to melt cast iron. I suggest that you check his channel out. This video ua-cam.com/video/1DyeESQpac0/v-deo.html&pp=ygUUbHVja3lnZW4xMDAxIGZ1cm5hY2U%3D of his would be a good starting point but he has others on furnace building that would also be worth a look.... Martin

heil, the sand I use is called a "natural sand" because it came out of a quarry almost ready to use. The quarry was about 30 kilometers from where I live. All I had to do was sieve out some larger grains and adjust the moisture level. Deposits of ready to use sand like this were common but most have now largely been used up. Now the best one can do is either buy petrobond sand (expensive) or get as fine a silica sand as possible. this is not easy as sands fine enough are not common, but one possible source is to buy the sand used for sweeping between just laid pavers. You then need to add about 10% of bentonite to the sand mix well and then add just enough water to make the sand about as moist as soil for a seed bed -- damp but not wringing wet.....Martin

@@olfoundryman8418 Thank you very much brother Martin for your response and recommendation

joell, Thank you.... Martin

Joell Thank you (twice 😊).... Martin

Leaded, I did not machine the pistons, the pattern maker concerned did. But it is I think usual to do it much the way you have suggested....Martin

Batch, Yes, I guess I should have showed more. The runner connecting the sprue bottom to the feeder bottom and hence the casting were cut into the drag mould. You can see the runner and gate etc being cut at 27.00 to 28.00 in this video ua-cam.com/video/7Y5eWT1lPtE/v-deo.html hope this helps... Martin

Daniel, Glad to have been of help... Martin

Will, The wife was very loath to loan me one of those jars - she has a fair number and the were her mothers - irreplaceable now of course. She was terrified I would break it. Fortunately for my access to a warm bed I did not break it.... Martin

Lon, Thank you..... Martin

thedude, You have hit upon one of the reasons for undertaking foundry as a hobby - the ability to make bits that are otherwise unobtainable or to expensive. It can be a very rewarding thing......Martin

Dennis, Can't find one? Who would have thought? I would have reckoned that they would be everywhere. Your fascination for Military vehicles is obvious and I can understand it - I drove an Austin Champ for about 30 years - at least they can be driven on the roads and I do have pistons for them 😊. Sadly I am not well enough to help you directly but if you come to me at olfoundryman@gmail.com I will put you in touch with the foundry that took over my work when I retired, he has recently cast pistons for a couple of others..... Martin

crazy, Metal casting is a great hobby to get into. There is a bit of a learning curve but you can do such useful stuff with it. I started (on my own) at age 11 - just fishing sinkers in sand moulds lined with cardboard but it was enough to get me drawn in. Encourage the 8 years old's interest in "stuff" - so much better than in Facebook or whatever. Good luck.... Martin

@@olfoundryman8418Thank you for reply. My father was repairing a clutch or throttle cable for motorcycle when I was 8 or 9 (1960's) in the living room in front of fire. (mother was out shopping). He had some very old moulds so made some lead soldiers and a dreadnought from WW-I. I got a history lesson as well