small part in cast iron

Discussion in 'Lost PLA casting' started by dtsh, Feb 5, 2019.

  1. DavidF

    DavidF Administrator Staff Member Banner Member

    No noticeable difference in the top down or bottom up gating. No difference on the choked gates...
     
  2. PatJ

    PatJ Silver Banner Member

    That is very impressive indeed !
    Have you put a file to the edge to see if they are machinable?
    I see a lot of potential there.
    What about making a 3D printed mold to make the same parts in wax?
    Would that make sense?
    SW has a function that allows a corebox to be made from a 3D model.

    .
     
  3. DavidF

    DavidF Administrator Staff Member Banner Member

    I'm thinking permanent iron molds for aluminum castings ...
     
  4. Jason

    Jason Silver Banner Member

    Yay! Love it when a plan comes together. Nice job fearless leader.
     
  5. DavidF

    DavidF Administrator Staff Member Banner Member

    Oww, Oww Damn!! Think my ego just ruptured.... dont just stand there give me a beer quick!! :p

    Got the air compressor down to the new shop, brought the wiring, brought the shot peen cabinet.....Totally forgot the air line :oops: And have no idea where my files are at o_O I want to finish cleaning these things on up so I can put and ending to this project...
     
  6. oldironfarmer

    oldironfarmer Silver Banner Member

    Great work on the lost PLA.
     
    DavidF likes this.
  7. DavidF

    DavidF Administrator Staff Member Banner Member

  8. ESC

    ESC Silver Banner Member

    Beautiful David.
    You never mentioned what you melted, but sure is a nice clean casting.
     
  9. Jason

    Jason Silver Banner Member

    Shell is super forgiving. It doesn't care if you pour metal upside down or inside out. Love it!
     
  10. DavidF

    DavidF Administrator Staff Member Banner Member

    I was a cast iron flange off a pump. pretty sure its a 30 class grey iron. I throw in one big chunk and get it melted first while preheating more smaller on to of the furnace. Once the main chunk is melted I skim it then start adding the rest on bit at a time. This seems to really reduce the amount of slag that is formed. No additions were made to the melt....
     
  11. ESC

    ESC Silver Banner Member

    Thanks.
    I have been getting away from the steam radiator breakage lately, because the interior has so much rust from the years of usage that ends up as gobs of slag. I like it for the fluidity the phosphorous adds, but the oxides and other contaminants from the steam make a mess.
     
  12. PatJ

    PatJ Silver Banner Member

    I would have assumed that you added phosphorus to the melt to get it to fill so well, so that is impressive.
    Surface finish is first rate; I don't think I have ever seen better than that.

    Looks a little hard, but the surface tends to be hard on cast iron parts anyway, and it looks like you were able to break through that and so some filing.
    Even if the parts were chilled a bit, I think you could anneal/temper the parts and get them machinable.
    In the past the parts I cast in iron that were this thin were basically pure tool steel, and untouchable with anything but a grinder.

    It is my understanding that parts with phosphorus added can be brittle, but for small engine parts this may or may not be an issue. I have never used phosphorus so I can say definitively one way or the other on the brittleness issue.

    This is quite a process.
    Very impressive work.
    Hats off to you.....
    .
     
    Last edited: Mar 16, 2019
  13. DavidF

    DavidF Administrator Staff Member Banner Member

    Drilled one of the castings today with a 1/4" drill bit, cuts like butter with no surface hardness :cool:

    The surface does have a bit of a dragon skin look to it. This was caused by the way the first coat of slurry dried. Ill have to see what is needed to correct it on the next tests. What I did on this run was to apply the first coat of shell by itself with no additional backup sand. I though that by not adding sand to the first coat I would get a better finish. Now the question is did I need to just add a second coat of slurry without sand to correct it, or did I need to add sand to the first coat?? Guess I better go back and look at the directions LOL
     
  14. DavidF

    DavidF Administrator Staff Member Banner Member

    Yep, should have sanded the first coat....see at 2:55...
     
  15. Jason

    Jason Silver Banner Member

    Where the hell was that video when I started using this stuff?:rolleyes: Interesting they want ZR for the primary coat and then FS for backup coats for ferrous stuff. :cool:
    Learned something new today. Glad to see you got away with having just FS on your plastic parts.
     
  16. DavidF

    DavidF Administrator Staff Member Banner Member

    Went to the post office 3 times yesterday, parts are all boxed up and ready to ship, but ill be dammed if I'm waiting in a line for 30 minutes just to mail a box. There was only one person working and she seemed to want to have a 15 minute conversation with every one that came in...:mad:
     
  17. oldironfarmer

    oldironfarmer Silver Banner Member

    She was planning to be there all day anyway.
     
  18. Jammer

    Jammer Moderator Staff Member Banner Member

    My P.O. as well. Nicest guy you could meet, but has to talk to everyone for 10 or 15 minutes. I think some of the old people go just to visit. Wait.... I'm an old person and he is an interesting person. :rolleyes::rolleyes:
     
  19. PatJ

    PatJ Silver Banner Member

    LOL, the ones around here tend to be rude and surly, and have a chip on their shoulder.
    It is like they are doing us a favor by taking our tax money in that fat salary, pension, health insurance, etc., etc.
    And they are absolutely slow as molasses in the winter.

    I despise going to the post office.
    I would rather have a root canal.

    .
     
    Jason likes this.
  20. Jason

    Jason Silver Banner Member

    OMG, Don't get me started on the Post Office... I'd rather spend all day at the DMV standing in line, barefooted on broken glass!
    20190313_143243.jpg
     

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