Saucer Cup & Spoon – The Lost Foam Edition

Discussion in 'Lost foam casting' started by Al2O3, Mar 22, 2020.

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  1. Tobho Mott

    Tobho Mott Administrator Staff Member Banner Member

    Amazing!

    Jeff
     
    Tobho Mott, Apr 1, 2020
    #41
  2. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Thanks for the comments and Likes fellas. They are much appreciated.

    With Spring and relief from the cold approaching for the Northern Hemisphere and Fall and relief from the heat for the Southern Hemisphere, and the call to arms to combat the global pandemic with social distancing and all, I DECLARE IT CASTING SEASON!!!

    Time to start the next project.

    Best,
    Kelly
     
    Al2O3, Apr 1, 2020
    #42
  3. Mark's castings

    Mark's castings Gold

    Yep the winter casting season is upon us too now, the weather is finally cool enough to run a furnace without heatstroke.
     
    Mark's castings, Apr 1, 2020
    #43
  4. OMM

    OMM Silver

    Kelly, (sorry about the edit but) these are very wise words.

    Most nonessential services have been closed down in my area for good reason. A new pandemic lift might be in the way with a new self declaration form.

    Have you or anyone you have been in contact with in the last 14 days been outside the country?
    Have you or anyone you have been in contact with in the last 14 days being in groups of larger than 50?
    Have you or anyone you have been in contact with in the last 14 days been a hospital or any knowledgable infectious disease center?
    Have you or anyone you've been in contact with in the last 14 days used public transit?
    Have you or any of your direct family household have had any contact of above?

    We have personally been given another two weeks... With a one-week start up protocol. It looks like three more weeks from today at best.

    So I agree a lot can be done in your backyard in the next three weeks!

    Please play safe as the fire department, ambulances and hospitals... tick off personal contact above for you and your family members.

    p.s. I did need those videos to see what you meant by the overhead vacuum. The plastic bag made total sense!
     
    Last edited: Apr 1, 2020
    OMM, Apr 1, 2020
    #44
  5. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Thanks Mark.

    I wish the film membrane was my idea but that's pretty much been standard procedure in the commercial setting for many years, and it's quite clever. The thin disposable bag is just a convenient material choice for me because they are transparent, pliable, fit the flask well, and are free & abundant.

    When I first used the vacuum method several years ago, I put a rubber band around the rim of the flask and cut a hole over the sprue, neither of which are necessary nor produce any detectable benefit. We're not talking high vacuum here and the 2-3" of sand pressure on the film/bag contact against the flask seals remarkably well and pouring through the 1" diameter of the membrane over the sprue is a drop in the lost foam bucket. One thing that does happen when you pour is the membrane melts away outward from the sprue and eventually becomes several inches in diameter. That's where the additional flow/volume capacity of the vacuum cart is helpful.

    My vacuum cart measures the level of vacuum at the cart inlet. I can't measure any difference between the cart inlet and the bottom of the flask but I'm sure the vacuum degrades as you progress upward through the flask and approach the film opening around the sprue.

    I have had several questions regarding vacuum use on the YouTube posts. The good news for lost foam aluminum casters, I almost never use vacuum, and most all issues can be avoided with a reasonably thin permeable pattern coating and good casting feed system design. For me, it's only been necessary in the extreme circumstances like very thin walls or very long metal travel distances. But......Most of my castings are ~1/4" wall and still have relatively high surface area to volume ratios (SA/V), so they vent well through the pattern surface.

    For the the 100+ carburetor castings in my last project, I don't think I saw nary a flash or puff of smoke in the pouring cup but in the vacuum pours in this project I did see some. I think that was because sprue and feed system were lower SA/V, and the vacuum was advancing the metal and evaporating foam faster than it could vent through the feed system area. So if you are casting objects with high volume and low area, you'll likely see the liquid and gaseous foam buoyantly bubble back up through the sprue and burn on the surface of the pouring cup when it contacts air. I try to avoid that.

    It's a lot of analytical nuance but does tell me I have my coating & process pretty well optimized for my typical castings.

    For iron lost foam casting, vacuum seems to be much more important. The very high temperature of iron and the higher density/sprue pressure make it evaporate the foam pattern at higher rates causing gases to evolve more quickly. The commercial ferrous lost foam coatings have higher permeability and the vacuum greatly aids removal from the pattern evaporates. Bronze is a tweener.

    Best,
    Kelly
     
    Al2O3, Apr 2, 2020
    #45
  6. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I mounted them.

    32 Mounted.JPG

    The project is wall art now.

    33 Wall Art.JPG

    That’s a wrap.....

    Best,
    Kelly
     
    Al2O3, Apr 4, 2020
    #46
    Tobho Mott, Gippeto, FishbonzWV and 1 other person like this.
  7. Mark's castings

    Mark's castings Gold

    Can you make a bowler hat that can be frisbeed at attackers as a weapon like the Goldfinger villain Oddjob?
     
    Mark's castings, Apr 4, 2020
    #47
    Mark Kravchenko and Gippeto like this.
  8. rocco

    rocco Silver

    We're all pretty sure he could so, I think the correct question is would you?
     
    rocco, Apr 4, 2020
    #48
  9. Mark's castings

    Mark's castings Gold

    Mate, if I could make a cast aluminium tactical bowler hat (available in a wide range of flocked colours) they would be for sale on Ebay already.:D
     
    Mark's castings, Apr 5, 2020
    #49
    Mark Kravchenko and Gippeto like this.
  10. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    -Crack me up :p

    K
     
    Al2O3, Apr 5, 2020
    #50
  11. rocco

    rocco Silver

    I don't know, it's a little hard to be inconspicuous wearing a bowler, you'd be giving away your tactical advantage, I mean when's the last time you actually saw somebody on the street wearing a bowler hat?.... Now, on the other hand, if you could design an effective cast aluminum tactical ball cap, you might be on to something.
     
    rocco, Apr 5, 2020
    #51
  12. Peedee

    Peedee Silver

    Come to England, we all wear bowlers a pinstripe suit and sing chim-chimeny whilst waiting for Mary Poppins........ ;)

    All joking aside I have given serious thought to opening a hatters/millners in the hope of ripping off the rich/wannabe posh folks in this village.

    Edit: For refernce I wear a flat cap but I'm not from Yorkshire and I don't own ferrets.
     
    Peedee, Apr 5, 2020
    #52
    Mark Kravchenko, Redwolf947, Jason and 2 others like this.
  13. Mark's castings

    Mark's castings Gold


    That description reminds me of the dustcover biography for Douglas Adams in one of his books: "He is not married, has no children and does not live in Surrey".
     
    Mark's castings, Apr 5, 2020
    #53
  14. Stevan

    Stevan Copper

    Totally frigging impressive. Never imagined you could cast something so thin. Will be giving this sort of thing a try. I tried casting a foam cup once in greensand and only got the bottom half.
     
    Stevan, Jul 23, 2020
    #54
  15. Jason

    Jason Gold

    That thing has been like a right of passage among metal casters for years. And no, I won't be casting a spoon,cup and saucer. I've got F all to prove to anyone.

    I guess in my next video, I'll have to pull out my flat cap for Peedee.
     
    Jason, Jul 23, 2020
    #55
  16. rocco

    rocco Silver

    Yeah, but not like this! Kelly is the only one that I'm aware of that's pulled it off using the lost foam method.
     
    rocco, Jul 23, 2020
    #56
  17. Jason

    Jason Gold

    You're right! Coated lost foam or ceramic shell lost wax would be child's play compared to doing it the way the professionals do it. Not to take anything away from Kelly's work
    by any means, but sand casting that thing from patterns would be a king sized pain in the ass! And DON'T even try to guilt me into doing this. Not a chance in hell!;)
     
    Jason, Jul 23, 2020
    #57
  18. rocco

    rocco Silver

    I'm constantly stunned and amazed with what Kelly's able to accomplish with foam. As for the cup, saucer and spoon with conventional sand casting, I'm with you, not a chance in hell for me either.
     
    rocco, Jul 23, 2020
    #58
  19. HT1

    HT1 Gold Banner Member

    i've said it before, I'll say it again
    Kelly does more with Foam then I thought was possible. and I'm hard to impress,

    and well:cool: maybe if someone offers me a pay raise, I'l do another out of brass just for S&G
    [​IMG]
     
    HT1, Jul 23, 2020
    #59
    Mark Kravchenko, Jason, Tobho Mott and 1 other person like this.
  20. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    HT1's saucer cup and spoon required molding skill........mine required no molding skill........just dump in the sand and rattle it in place.

    A brass one would be cool HT1.

    Best,
    Kelly
     
    Al2O3, Jul 23, 2020
    #60
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