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Kang

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About Kang

  • Rank
    Master
  • Birthday 01/17/1973

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  • Gender
    Male
  • Location
    Ottawa, Ontario, Canada
  • Interests
    My wife and kids, backyard metal casting, A Song of Ice and Fire, minis

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  1. Rammed up a few test molds over the weekend and cast one of them in Everdur silicon bronze. My first time casting this alloy as well as the first casting poured in the new sand. Also made up an ingot mold with some of the new sand. Also made a couple of styrofoam skull belt buckle patterns to cast in the same bronze alloy. The new sand did not have as much "green strength" as the commercially made sand I'm used to, meaning that the molds were more crumbly. The sand casting and ingots came out of the mold with the sand stuck to the castings in a thin layer that I had to remove with a wire brush. Sand that does this is known as having poor 'peel'. Carbonaceous sand additives like powdered sea coal are known to improve peel, but is normally reserved for ferrous (iron/steel) casting. I need to level up a few times before taking a run at cast iron, cripes I almost burst into flames manupilating a crucible containing 30# of molten silicon bronze! That's closer to 1000 than 500F cooler than cast iron. Organic additives are said to improve peel, and corn flour supposed improves green strength... So I'm thinking of adding some so that it makes up maybe 1% or so of the sand's dry weight. The ingots has scabby looking marks on their undersides which I have identified as being caused by metal penetrating into the sand. Maybe I could have done a better job ramming up the I got molds, no big deal. I'm far more bothered by the peel. The sand casting did not fill, but I had not added any venting to the mold, and the same casting in aluminum had failed to fill in similar fashion when I molded it without venting in the old sand too. The bronze also has pinholes in some areas which could come from all sorts of things, but I suspect my having left the mold to sit overnight and dry out slightly was a likely culprit. I was surprised how brown the casting came out of the mold, like it had been given a patina. My aluminum bronze axes always came out looking like shiny metal, but then, non-molten aluminum bronze is resistant to oxidization and will not take a patina easily... The belt buckles... One was a great success. The other, a dismal failure. The Dreaded Sand Float strikes again! I knew it was a failure when I saw the sand on the surface of the mold get pushed upwards from below during the pour. Sand Float defects are so weird! The top part of the casting in the mold gets pushed upwards on a raft of molten metal, separating it from the bottom part. - See how one side of the belt loop stayed right against the back of the slice of skull, while the other side got floated? So bizarre... Back to the lab to see what I can do to get my sand working right... I thought building a muller would make it easy to make my own greensand. Turns out it also makes me have to do a whole bunch more research on what actually goes into good greensand. Lucky for me I enjoy this sort of thing... Here's about a 15# ingot preheating next to my dross skimmer by the exhaust vent in my furnace lid: One more craziness that happened during that session: See the turnbuckles used to support the weight of my furnace lid? I found out their tighteners are NOT made of steel when BOTH of them melted and fell apart halfway through melting the bronze! Kang PS. All pix were taken after I brushed the stuck on sand off the castings.
  2. Last post was Big Bucket Mull chewing up some old greensand to bring it back to life; here is the true test of his functionality: making new greensand! https://youtu.be/CNzKwx2Qb0s If you enjoy watching noisy machines go round and round, you might just get a kick out of it. Here's a pic of a test mold half I rammed up after making four 15kg (dry) batches: All in all, a great success. Woohoo! Next upgrades will be to attach a repurposed microwave oven timer so I can set the muller to run for so many minutes then automatically stop and beep at me to let me know, as if all that racket suddenly stopping won't be enough of a clue... And casting a wider wheel so it will roll over twice as much sand with each revolution. Kang
  3. Oh gosh, seems like I forgot to post the video where I installed the second scraper! Well, too late now, you can find it on my YT channel if interested, but this one is gonna be way more fun to watch... which may not really say all that much. Well, maybe not, the last one did have my first attempt at blacksmithing in it, which was a lot of fun... Which you would think I would do more often, given that my youtube name is Tobho Mott... If there were any metal casters in the (ASoIaF) series, I'd have used their name instead. Drogo vs. Viserys doesn't count; there's no way you can melt gold medallions in a soup pot over an open fire like that, sorry George. Anyhow... so, we had a nice weekend, rain free for a change, at least until after dinner on Sunday... Point being, I actually got to put my Tobho Mott hat on and get some work done out in the Forges of Qohor (Northern Branch), AKA my backyard foundry! Long story short, I finally got the muller working, and chewing up some real greensand! Short story long, there is video! Ok the forum is not giving me the usual option to display that as a link instead of an embed. If a mod could fix, I'd be very grateful. It won't even let me remove it! Not quite working perfectly yet, but it is working and it is mulling sand. The one change I made to the muller before testing it with real greensand was rotating the 2nd (center) scraper a bit to improve its angle. So far I've only used it to recondition my greensand (purchased from a foundry products supplier here in Ontario), not yet for making my own greensand from the ingredients pictured earlier. I wound up putting way too much water in the first batch, and maybe a little too much (not 100% sure) in the second. Pictures! Mixing dry to see if it will break up lumps (it does this better with water added, though the big lumps take some time to make their way under the wheel either way): Way too much water: Squeeze test: far too wet but super sticky! Another batch, used less water this time: Seems to handle half a 5 gallon bucket of greensand just fine, though 3/4 of a bucket was too much for it when it had way too much water in it, it got so sticky (technical term: "stickier as frig") it just sat there in a big clump when I tried to dump it, the drum kept turning but the sand held together and let the drum just spin/slide under it and would not turn over. That part is at about the 12 minute mark if anyone wants a laugh at my expense. Still getting used to just pouring the water in I guess; I always used one of those little pump-up garden spray bottles before this, to add it as more of a mist. But with a muller, that is no longer necessary. Youtuber Olfoundryman, one of my home-foundry heroes, left a comment saying I should ease up on the spring tension because he thinks my wheel is pushing sand to the side instead of rolling over it. He does not use a muller but he REALLY knows his stuff; Youtuber Chirpy's Tinkerings (a friend and fellow metal caster) thinks I need a wider wheel, and I do not disagree; Youtuber Worldtraveler (another friend, who does lost wax casting) says I was right about moving the wheel over an inch so the whole width of the wheel is rolling over the area where the sand was sticking to the wheel as it stands now, rather than just half of it. I'll agree with basically anyone who says I'm right, so that's good too... :) I'd like a wider wheel and IMO that would accomplish the same thing as moving the one I have over a bit as well as making it harder for sand to get pushed to the side... I would cast one if I had a lathe to finish the job. Or I could buy another wheel like I have and put them side by side, though they would have a gap between them. A guy on one of the casting forums suggested I could cut off the part of the hubs that stick out past the edge of the rims, to make 2 wheels able to sit flush against each other and not leave a gap between them. It's a possibility... I think it is working pretty well, so any more changes would be just to make it work a little better, or perhaps work just as well only a bit faster. Mind you I haven't tried making new sand yet, possibly I will learn about more flaws in my build when I try that... Hope you guys are enjoying this look at my OTHER weirdo hobby... Kang
  4. Well, the muller build has slowed a bit. Easy enough to blame going on vacation and the kids both having their birthdays last weekend, but to be honest work has me a little burned out, so I've just been too tired to get out in the shed and work on stuff... But I did get the first scraper built and tested fitted... Click image to watch the YT video: Since then I have also mostly finished building the other scraper and fitted it, but it needs some bending, which means I need to find my torch to heat it up so I can hammer on it and make it move. That will be my first attempt at forging, I'm looking forward to that! Then I want to caulk up the gap around the edge of the muller floor to keep the sand from slipping down there as mentioned in the video, and it'll be finished... aside from minor adjustments. THEN I can try to make some new greensand! I have the ingredients readu to go too: finely powdered bentonite clay, and fine silica sand... The sand is a respiratory hazard, silicosis is no joke, but I will be working outside and once the mixture is mulled and tempered with water, it should stay moist enough to keep the particles from going airborne and getting inhaled. Kang
  5. Kang

    Ral Partha Friendly Cleric, comparison shots

    Ooh, I like how you threw in a bonus old school mini there. I have the potbellied guy somewhere too, possibly even with all his parts intact! Kang
  6. Cool! Haha, yeah Mary, I've never used a mill or any other real machine tool either, but I've become aware of what they can do through my metal casting hobby. One thing I know for sure is, the machines are quite hypnotic and relaxing to watch running. I could spend hours watching a shaper do its thing... Hey Djinn, do you know about David Gingery's 7-volume "Build your own metal working shop from scrap" series? Gingery literally wrote the book on building your own milling machine. The individual books (1: charcoal foundry, 2: lathe, 3: shaper, 4: milling machine, 5: drill press, 6: dividing head & accessories, 7: sheet metal brake; then there are numerous other books not in the numbered series as well.) are cheap and can be ordered online or downloaded from the kindle store, and may provide some ideas and/or inspiration. If needed. Kang
  7. Kang

    DSM7989, Maid Marian the Fox

    Nice. I expected a red fox like Disney's Maid Marian, but I like the way you went with it! Kang
  8. More pix of Big Bucket Mull's scraper assembly clamps, 2 of which are now finished up and functional... They tighten up well, I think they'll be able to keep the sand from making the scrapers push out of alignment. Also, a new video showing how I made the clamps, plus a close up look at the big homemade melting furnace I call Balerion the Black Dread. AND some gratuitous fire scenes. If you look closely you'll see me using Tong Belwas for the first time, to add ingots to the hot crucible. That went well, and cleaning the chunks of blubber out of Lightbringer the waste oil burner's needle valve worked wonders! Adjusting the fuel/air mixture just got so much easier with that done. https://youtu.be/z4MYJhq6HQ Enjoy! Kang
  9. Good weather at last! Finally. Good enough to get out into the foundry, fire up Balerion the Black Dread (the melting furnace), and cast some parts for Big Bucket Mull (the sand muller)! 8 clamps (more than I need, always pays to cast extra when using lost foam casting in case one or two don't come out right) for attaching lengths of pipe to the crossbar. The pipe sections will hang down and have the sand scrapers (that push the sand into the wheel's path) attached to the bottom ends. The clamps have since been cut off their sprues, cleaned up on the belt sander, had their bolt holes drilled, and a slot cut out of the ends that you can see in the pic were attached to the central pouring sprues. A bolt will be tightened up to close up this slot so the clamps will be tight on the pipe and keep it from moving. In theory anyhow. If that doesn't work, I'll simply re-melt the clamps and try something else! :) Follow up from some earlier posts: Tong Belwas (the pliers-tongs) worked great, and Lightbringer (the oil burner) worked better than ever now that I've scraped all the chunks of blubber out of the needle valve. AND I even found my long lost favourite sand scoop while I was setting up the molds! Yup, gonna be a good casting season, I can tell already. Kang
  10. Ah, gotcha. Thanks for watching and asking, I'm not trying to be mysterious, so I'm glad you reminded me I hadn't explained it all... To sum up, all that mashing and smearing etc. causes each grain of sand to end up with a thin layer of clay coating it, in a much less boring and laborious way than hand- and foot-mulling. Not to mention faster and more effective. Kang
  11. It is Big Bucket Mull, former cement mixer and current partially built sand muller, designed for making and rejuvenating the molding sand which I use for casting historical replicas of the Valyrian Bronze axes George R. R. Martin keeps forgetting to mention having been used by the First Men of the Dawn Age of his fictional world. And such. It rolls and plows and squishes and squashes and smashes and bashes and mashes and scrapes and smears the sand/clay/water mixture into suitable fluffy sticky awesomeness for use, or rather it will when I'm done building it. Having become inexplicably obsessed with backyard metal casting during an annual late September camping trip in 2013, I have been gradually building and upgrading the Northern Branch of the Forges of Qohor in my backyard over the past four and a half years or so. Most of the pictures I have posted earlier in this thread are being held hostage by Photobucket but I have linked serveral videos from my 'Tobho Mott' youtube channel (where A Song of Ice and Fire fandom and backyard metal casting intersect) above if you're interested in seeing more about the greensand and lost foam casting processes, how I make molds and operate my homemade foundry equipment such as Balerion the Black Dread the big waste oil fired melting furnace, Lightbringer the drip injector waste oil burner, Ser Robert Tong the crucible lifter, King Robert's Rammer the sand ramming tool, and a host of other beloved characters and artifacts. Thanks for asking; check it out, I believe you'll get a kick out of this particular internet weirdo's OTHER lunatic hobby! Kang
  12. It's alive!!! But it still needs scrapers and sweeps and plows installed and adjusted. Edit - Oh dear, my animated .gif has been removed, thanks for bringing my post into compliance and apologies for not realizing/remembering those attachments aren't permitted! The rolling muller wheel that was in the gif can be seen toward the end of this video if anyone's interested: https://youtu.be/KDHYGShp048 Sorry about that, won't happen again. Kang
  13. Kang

    Boxer Rebellion: Box-Turtle Folk, WIP

    Castings look great, it's almost a shame they're only for making armatures... Edit - this comment was not intended to diminish the role of armatures. :) Kang
  14. Kang

    01608: Diva the Blessed

    Makes.me want a pic of the mimic chasing the yellow wizard! Great stuff as always, Kang
  15. Kang

    My Journey into Lost-Wax Metal Casting

    You can get small amounts of LoS (still probably last you ages for this small stuff) on a popular auction site for quite cheap compared to the big sculpture supply people, get the solid form; premixed it won't keep. From what I've read... Kang
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