Beginner to melting cast iron.

Discussion in 'General foundry chat' started by Ironsides, Mar 21, 2023.

  1. Ironsides

    Ironsides Silver

    I had a viewer make a comment on my channel that because of me he had a go at melting cast iron and does not want to melt any other metal. Great to see another backyard melter watching my videos and making some great house numbers. He uses graphite as a coating on his sand molds and the sand comes off cleanly. He made two short videos about those castings, have a look at them.



     
    Tobho Mott and Tops like this.
  2. Tops

    Tops Silver Banner Member

    Very interesting small pieces!
    Do you know how he is making patterns? Some neat background textures and crisp lettering.
     
  3. Melterskelter

    Melterskelter Gold Banner Member

    Does he have any vids showing his methods? What I THINK is see is that he is using bound sand---probably sodium silicate which is quite practical for those palm-sized plaques. The bound sand is enclosed in a mold frame more than a flask. By adding 5 to 6% sea coal or graphite to his sand he should expect his sand to separate from the metal just as he shows or with a distinctly shiny surface and excellent get very detailed rendition of detail as this is what I see every time I use such a slilicate core. He is probably 3-D printing his patterns---also very practical for one-offs or few-offs and would offer background texturing.

    Now let's see how far off base I will likely be on this...

    Denis
     
  4. Ironsides

    Ironsides Silver

    Have close look at the second video, you will see the layers where he has used a 3d printer on the smaller signs. I would say that the larger house number was made the same way. 3d printers are the way to go for making patterns if you can afford buying one and the on going costs buying the plastic wire.
     
  5. Ironsides

    Ironsides Silver

    Definitely not bound sand (silicate) because I used it for many years, it is green sand because it peels of the casting in large amounts. When I used silicate sand it would leave very little on the casting because bound sand is so strong.
     
  6. Ironsides

    Ironsides Silver

    I forgot to mention that he melts cast iron with propane which blows out of the water the myth that propane will not melt cast iron.
     
  7. Melterskelter

    Melterskelter Gold Banner Member

    So does he or do you intend to fully inform this forum of his techniques so we can learn from him?

    I am sure some folks considering propane might like to know what burner and methods he uses to do that.

    Similarly, others may wonder what his sand formula is. How does he apply the graphite. How much?

    Just to know he does something arouses curiosity but does not help us move forward.

    Denis
     
  8. Ironsides

    Ironsides Silver

    All you need to do is look up kursor612 on youtube and comment on one of his videos so you are getting it straight from the horses mouth.
     
  9. Melterskelter

    Melterskelter Gold Banner Member

    I did post a multi-part question/comment on one of his video this morning. Let's see what we learn.
    Denis
     
  10. ESC

    ESC Silver Banner Member

    The block, heads and water pump of the engine in my avatar were poured in cast iron using only propane for fuel in a Petrobond mold. I built the Gingery Crucible furnace which had an 8" bore and accepted a#8 crucible. The build included the centrifugal fan and gas burner inlet.
    Ironsides sketched up an oil fired burner for me at a North American Model Engineering show in 2006 or so which convinced me to use waste oil. Around 2015 I built a Nudge burner that used a bounce house fan, but the small bore required a minimal flow of propane at the same time to maintain combustion. I have seen temperatures on the back wall of 2700 F with an optical pyrometer.
    That original lifting body furnace lasted twenty years on the castable refractory.
     
    Last edited: Mar 23, 2023
  11. Al Puddle

    Al Puddle Silver

    I have a beginner question. Are laminations from small motors and transformers good stock for iron casting?
     
  12. My friend Peter with the small foundry has been accused on occasion of using "special gas" by people wanting to know where he buys it. It makes for some interesting discussions when people flat out refuse to believe it's propane.
     
    Ironsides likes this.
  13. These days they are typically 4% silicon steel if good quality: grain oriented silicon steel GOSS. So the melting temp would be higher than iron and you'd have to get carbon into the melt to make iron. Brake rotors can be a good source of iron.
     
    Last edited: Mar 23, 2023
    Ironsides likes this.
  14. Ironsides

    Ironsides Silver

    Mark gave a good reply but I add one more thing, Sheet metal can be a poor choice in any metal to remelt because of the poor recovery rate. Sheet metal can be very thin and burns in a furnace unless a flux cover is used. Aluminium swarf is a text book example of what not to melt.
     
  15. Melterskelter

    Melterskelter Gold Banner Member

    Well, no response so far after posting a comment/question early yesteday morining. another possible binder for his sand could be epoxy. My experience with epoxy which I have used only a few times as a binder has been that it has registered excellent detail and the sand does simply revert to a dry unblound condition after pouring iron in it. It also has yielded a very nice sirface finish. Too bad he has not responded....

    Denis
     
  16. Ironsides

    Ironsides Silver

    I had a look at all his videos and could not find your comment.
     
  17. Melterskelter

    Melterskelter Gold Banner Member

    Ya, he must have deleted it. I was hoping he might share information. If you look through his casting vids, you will see he has no.comments whatsoever. So, it must be that he just deletes them.

    Denis
     
    Last edited: Mar 29, 2023
  18. DaveZ

    DaveZ Copper

    It appears to me that there is very little draft on those letters and numbers. I viewed his channel and asked him about that. He replied that he cuts them with a laser and in fact doesn't have much draft. Don't know how they pull cleanly, they are fairly deep.
     
    Tops likes this.
  19. Tops

    Tops Silver Banner Member

    He may be getting a little extra release from the charred edges of the patterns acting like a graphite or parting powder.
    I would imagine the laser making a tapered kerf too.
    Any inkling if he's running CO2 or UV laser?
    I did some UV lasered cereal box cutouts glued to existing patterns and the detail was pretty good, but it was maybe only .020" /0,5mm deep.
     
    Last edited: Mar 30, 2023
  20. DaveZ

    DaveZ Copper

    I believe he said CO2
     
    Tops likes this.

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