I just hvent been doing enough naked women lately

Discussion in 'Lost wax casting' started by Mantrid, Aug 27, 2022.

  1. Mantrid

    Mantrid Silver

    Bit thick for solid pour. The main sprue would have to be at least as thick as her waist to avoid shrinkage and metal tearing. Also it would be a little on the heavy side. Its said that a good bronze can be defined by how thin you can make it.

    Im looking forward to the welding. Its something I enjoy but I am so out of practice.

    How is the magpie going?
  2. DJN Holistic

    DJN Holistic Silver

    I'm very interested to see your welding work. Of the whole process, it's the part I have the least experience with.

    The magpie is having a snooze on my shelf. I wanted to adjust the angle of it's head but that threw off some other parts. I was feeling a bit frustrated so I side-lined it for a while and moved onto another project that was halfway done. I can't do any casting until summer anyhow, so no point in rushing it. I'll post some pics of the second project once I've finished the moulding. It's a fairly large piece and needs seven moulds total. I've done the body and head, just got to finish up the rest.

    Attached Files:

  3. Mantrid

    Mantrid Silver

    The kangaroo is the new project? How big is it that it requires 7 moulds. It looks more bas relief than a conventional sculpture Should be fairly straight forward.
    I will take some photos of my welding before grinding so you can see just how bad it is. I'll be going away for a month so wont e for a while.
  4. DJN Holistic

    DJN Holistic Silver

    Yeah, the Roo is the new piece... well kind of. I made it about a year ago as an experiment to see if I could sculpt with common hardware store materials. Settled on cement and tile grout. I wasn't planning to do anything with it, but it ended up being my most upvoted post on social media, so why not go all the way? It's about a bit over a foot tall and long. The 7 pieces are body, head, tail, 2x legs, 2x arms, but it'll make more sense when you see the wax.
  5. Mantrid

    Mantrid Silver

    Went a bit thicker than needed on the shell. Just being over cautious to avoid any nasty suprises

    Tobho Mott likes this.
  6. Mantrid

    Mantrid Silver

    Cast this today. Got a good cast after some unusual behavior in the crucible. I had some bronze sprues and a pouring cup from a previous casting. Also had some measured out copper wire and manganese and silicon.

    I started with the bronze silicon and manganese in the crucible. The plan was to melt that then add the copper wire.

    All melted well, then I added the copper wire. The bronze was very fluid and well above the melting point. But some of the wire wasnt melting. I thought maybe the wire wasnt copper but steel. So I fished it out and replaced it with the same weight of copper pipe.

    However, much of this wouldnt melt either. So I decided to fish it out and cast with what I had that was liquid.

    The cast came out great, however I initially thought it was copper not bronze because of the colour. But it turned out just to be some sort of oxidation on the surface.

    Left in the bottom of the crucible was alot of black material which broke up into a powder when I scraped it out. Never seen that before.




    Last edited: Jan 19, 2023
    Tops likes this.
  7. DJN Holistic

    DJN Holistic Silver

    Looks very coppery, so some of it must have melted. Is the gold patch on the elbow from the metal being a tad too hot? I've noticed that happen from time to time, sometimes with crystalline patterns in it?
  8. Mantrid

    Mantrid Silver

    The copper colour is just on the surface. You can see the actual colour of the metal where the sprues have been cut off. And it appears to be the usual colour of silicon bronze. Its was certainly very hot in the crucible while I was trying to get the copper to melt. Its really strange why some of it wasnt melting
  9. Mantrid

    Mantrid Silver

    the colour of the elbow is the normal colour I see on my castings. It is picked out due to the rest of the casting having this surface copper colour.
  10. Huckleberry

    Huckleberry Copper

    Looks great, show more pics as you go!
  11. Mantrid

    Mantrid Silver

    After a full sandblasting I could see all the defects in this casting. I spent some time with the grinder and welder doing some repairs however it dawned upon me that it ould take a long time and considerable effort. Also the corrections would change the sculpture from the original too much. So I decided to scrap this one. However I did get to practice welding the two part together, which went well.
    These defects are things I was getting in my castings many years ago before my long break. It seems I am repeating mistakes from the early days. Have I forgotten everything I learned? Time will tell.






  12. DJN Holistic

    DJN Holistic Silver

    I think those lumps in the crevices are the result of your slurry rather than your casting. What kind of slurry are you using? Those kinds of defects seem to happen when the mix is off, or if the wax was either too greasy or too clean. They can be fixed with a repoussé chisel to a degree, but there seems to be quite a lot on your figure.

    Nice work on the welding. I remember a while ago you said you made your own rods to match the bronze. Been meaning to ask you how you do that?
  13. Mantrid

    Mantrid Silver

    yes pretty sure its the slurry. Im not one for being precise with my quantities when making slurry. tend to just add the flour until it looks right. I will be more accurate on the next go.
    i use this as my flour
    this as my binder
    and these as my stucco layers

    In this case for the welding I just used the sprues as rods, as precision wasnt needed. Other occasions I cast thin wax rods that I attach to a suitable location on the sculpture and join to the pouring cup. They have two functions. They act as vents allowing air to escape and they partially or completely fill with bronze forming nice welding rods. The mould for these wax rods are made using an existing welding rod and silicone rubber to capture its shape. I use a syringe to squirt wax under pressure into the mould as the diameter of the rod is too narrow for the wax to flow into under gravity.

    Another technique that i havent tried yet is to stick a rod of wax around the circumference the piece you want to weld onto the sculpture (at the wax stage of course). This is usually a pattern to create a square piece of bronze to close a window in the finished sculpture. After casting this will result in a ridge of bronze already in the right place ready to melt down and fill the gap between the two pieces you are joining.
    Chazza and DJN Holistic like this.
  14. Chazza

    Chazza Silver

    Fantastic work Mantrid! I enjoyed your movies as well,

    Cheers Charlie
  15. Mantrid

    Mantrid Silver

    Thanks. Im Glad you liked them.
  16. Mantrid

    Mantrid Silver

    Its been along time coming but I've finally got around to doing part 3, the final part of this video series with this sculpture. Essentially the three videos details mould making and casting a wax copy. The videos leads on nicely to 4 others I did earlier that shows the casting process. Some time in the future I hope to do a few more on chasing the bronze and patina application and possibly mounting on a marble base. I learnt alot about editing videos and have better equipment for the future so hopefully the next ones I do will be better.

    Last edited: Mar 21, 2023
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  17. Jason

    Jason Gold

    I use Radnor c655 tig filler and the rods are a perfect match for the CMX sil bronze I buy. No need to make filler rods unless you really want to.
  18. DJN Holistic

    DJN Holistic Silver

    I'd like to get a Tig set up, but I'm a little intimidated to learn how to use it. I've used a bunch of filler rods before, but I find that even if the colour is 90% match, the chemical make up causes extreme differences with patina. Sulphur will turn the bronze black and the filler a toxic yellow colour for example. Heat applied patina like ferric will mask it to an extent, but it's not ideal.
  19. Jason

    Jason Gold

    I'm a one trick pony and only use sulfur. Never a problem for me. :)
  20. Zapins

    Zapins Gold

    Tig welding bronze is pretty easy. Even if you dip the tip into the puddle it still welds (unlike steel). Just pick up a torch and give it a go. Its easy.

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