Youtube Video Question

Discussion in 'Sand Casting' started by Sirgei, Aug 5, 2021.

  1. Sirgei

    Sirgei Copper

    Here is a video about casting on YouTube.
    At about minute 13, guy shows casting Aluminum into a mold made out of MDF.

    I went to local builders merchant and bought MDF board.
    Made holes with rotary saw and pouring channel.

    When I poured metal in - MDF BURNED. It produced a pillar of smoke.
    It filled with metal only halve way, and then pouring channel collapsed.

    How can he show it working on youtibe and in reality it don't work?
    Did he threaded his board with something?
    Like vinegar for example?

    I have fully read that book that was suggested to me on another thread.
    About Charcoal Foundry.
    Author saying it is fine to use steel crucible or cast iron pot, while metallab said that steel no good for crucible.
    Who is right?

    Before making charcoal foundry like in book, I am making a small one for a test.
    I will post picture else where when done.

    So, may be someone here can explain how this youtube guy casts into MFD and for me it hasn't worked.
    I am casting parts for bigger drilling stand using sand and gypsum.

    Thank you all
  2. rocco

    rocco Silver

    Easy answer, that's NOT aluminum. That melting set-up would never be able to melt aluminum and at around 11:58, he refers to the metal used in the sand casting, "a low temperature metal", he probably used the same low temperature metal for the MDF mold.
  3. oldironfarmer

    oldironfarmer Silver Banner Member

    You can use steel or cast iron in which to melt aluminum. It is not recommended because iron will contaminate aluminum and alter it's properties.

    I have used stainless steel to melt aluminum with good results. If you are not making a structural casting which needs to be durable then you can get by with a steel crucible.

    It is best to buy a proper crucible such as a Super Salamander.

    They both are right depending on the level of sophistication you desire to attain.

    I would not subscribe to the YouTube channel you posted. It is full of misinformation and poor techniques. Look for guys who know what they are doing. Some excellent ones are Myfordboy, Olfoundryman and Luckygen1001. You can trust everything they do.
  4. Oldarm

    Oldarm Copper

    Oh dear! At the very least this video needs a heavy edit explaining clearly and exactly what metal he is employing. This along with a warning not to even think about using anything else, not even lead. Already it has caught somebody unaware of the consequences of confusing aluminium and low melt tin alloys. At the very least, somebody is going to get "wet feet" when the wood mould self destructs or worse, a mini Vesuvius when the moisture in the wood mould is turned to steam
    I'm sure the video was produced with the very best of intentions but all the safety gear exhibited could be for nought.
    Having said that, I would like to know how he kept his flash/joint line down to just about zero in his sand casting especially if he was pouring an incredibly searching tin alloy.
    Jason likes this.
  5. Jason

    Jason Gold

    Ahh youtube experts.. The best place for bad information.

    He's obviously NOT pouring aluminum. You see that burner? It's some shitty camp stove. Looked like lead to me.
    Last edited: Aug 6, 2021
  6. rocco

    rocco Silver

    That particular video needs to be put in context, it's primarily just a demonstration of a foundry kit designed for use in classrooms with the intention of getting kids interested in the foundry industry.
    Last edited: Aug 6, 2021
    theroundbug and Melterskelter like this.
  7. theroundbug

    theroundbug Copper

    That's not even zinc. I've spilled molten zinc on mdf before and it didn't ignite, but charred and smoked like a mf, and my zamak castings always smoke petrobond and greensand. It's probably pewter, which makes it kind of funny he's wearing so much safety gear. But I do understand it's an educational video for classrooms.
  8. HT1

    HT1 Silver Banner Member

  9. 3Dcasting

    3Dcasting Copper

    As already commented, it is definitely not an aluminum alloy. I was going to say it's lead (that yellowish color) or some other low temp alloy.

    And generally never pour metal on MDF molds. This thing is nasty to inhale as is, not to mention the fumes it will make when burnt.
  10. Peedee

    Peedee Silver

    You can pick up a few kilo's of petrobond equivalent on UK ebay for around £20. Perfect results once you have fluffed it up by hand.
  11. Billy Elmore

    Billy Elmore Silver

    I have never gotten any flash when pouring tin. Dont think it likes the thin sections too much.
  12. Oldarm

    Oldarm Copper

    Certainly in a well made rubber or plaster mould I would not expect flash or even a significant joint line. However, take a wee look at the frozen introduction frame for the video. I see a very poorly formed joint line which is not reflected in his casting. (Suspecting a little clean up before displaying?) Been there, done that!
  13. Oldarm

    Oldarm Copper

    Sorry, I meant to add that tin and it's alloys are in my opinion incredibly "searching", that is why they pick up such incredibly fine detail. On my next RTV mould I will add a sprue for a fingerprint and see what happens.
  14. rocco

    rocco Silver

    That kind of surprises me since many types of solder contain a high percentage of tin for example, standard lead free plumber's solder is 95% tin, and it sucks into gaps like nobody's business, or as Oldarm says, it's "incredibility searching", I'm surprised it wouldn't do the same in a mold.
  15. Peedee

    Peedee Silver

    I think the 'wetting' reaction on something like copper would produce that nice flow, I'm not sure the same would be said for an inert material. Melt tin alloy on a silicone mat and it just balls up with lots of surface tension. That said, I remember having tin soldiers as kid so it must conform in the right circumstances.
  16. Billy Elmore

    Billy Elmore Silver

    I have very little experience with tin...played around with it for a couple of weeks setting up foundry in a box for school kids. I found it to have a very high surface tension and quite resistant going into small areas. Having said that it does pick up small detail with amazing accuracy as I too have seen fingerprints on the small castings we made for the school kids. Maybe it was the alloy or the zirconian sand we were making the molds with or the temp we poured them at...lots of variables.
  17. Peedee

    Peedee Silver

    I don't think we have played much with tin here, could be an interesting discussion.

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