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Kang

Kang's Kreations - Molten Metal Madness

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Borax is a very good general purpose fluxing agent.

Another is Dolomite, which is available at most Building Material Dealers in sacked quantities, or from Pool Supply Dealers.

Do a web search for Fluxing Agents and you will find more information than you need for this project.

GEM

Edited by Green Eyed Monster
Additional input.
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Geez, looks like I missed a couple replies!  Thanks, and sorry to all for not checking back sooner.

 

Fluxes are compounds that reduce the melting points of other things so they will flow better and farther.  Other things like metals... or like crucibles and furnace linings.  Borax is a flux that is used for bronze foundry as well as brasses and other copper alloys, and (I believe) precious metals.  I know it is not used for the type of aluminum foundry work I normally do, but the explanation of the reason why would be boring.

 

I do not plan to melt the chips from sawing up my ingots.  Extra flux (to help clean metal flow out of the dross more easily when it is being skimmed off) means extra wear and tear on my crucible and furnace, so if I'm only wasting a dollar or two in shavings by tossing them in the recycle bin or just shelving them, it's not worth the effort and the wear and tear on my gear that reclaiming it would entail.  The shavings would probably cause more trouble than they're worth anyhow; the chips would almost instantly become dross (due to being almost entirely surface area), and when I skimmed that out of my crucible, I'd be taking some more clean metal out with it no matter how well I fluxed the stuff.

 

I have tried melting aluminum cans once when I was just starting to play around with foundry work.  Waste of time, that metal is so thin that most of it burns (oxidizes) rather then melting.  Literally more than half of what you get is dross (junk) that needs to be skimmed off before you can pour anything, and that is after crushing the cans as much as possible to reduce surface area and taking the time to push each can beneath the surface of the melt to reduce oxidation.  I'd expect melting chips/sawdust to work about as well.  If I had been using some kind of cutting lube (I wasn't, but it's probably advisable), then that would mean getting even more junk in the pot to become dross and/or cause porosity defects inside the resulting casting.

 

I save the dross from my aluminum melts.  I could turn it in at a recycling center, not sure what it's worth but note, aluminum oxide is what the grit on most sandpaper is made of, so it does have some value.  Perhaps it could also be used in the making of refractory products used to line the next guy's melting furnace.  Probably some day I will try to melt a bunch of it down (well, melt the clean metal out of it would probably be more accurate) and flux the heck out of it to see how much metal I can squeeze back out of it.  I'm in no rush though.

 

Don't precious metals (gold, silver, etc.) come as shot pellets or something small like that, rather than ie. 30# gold bars (about the size of my ~15# bronze ingots, near as I can guess)? 

 

Hey, if you actually do ever find yourself cutting up 30 pound gold bars with your chop saw, you should definitely shoot some video...  Me and the other internet weirdos I mentioned in that video would truly enjoy watching that!  :)

 

Kang

Edited by Kang

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1 hour ago, Kang said:

Don't precious metals (gold, silver, etc.) come as shot pellets or something small like that, rather than ie. 30# gold bars (about the size of my ~15# bronze ingots, near as I can guess)? 

 

Hey, if you actually do ever find yourself cutting up 30 pound gold bars with your chop saw, you should definitely shoot some video...  Me and the other internet weirdos I mentioned in that video would truly enjoy watching that!  :)

 

Kang

 

:blink::lol:

 

No, I don't even intend to cut any gold on my chop saw. At $1300 an ounce, a 30 lb bar would cost $625,000.00.  It will be a while before I can afford that.  No I was actually referring to the filing that one does on say a gold ring after casting and cutting it from the sprue.  It is so valuable, that it is worthwhile catching those tiny filings and refining them.

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625K, eh?  Jeez, you could almost buy a tiny little house with no driveway and barely any yard in Toronto with that!  Almost, but not quite...  Just ask my sister, who the house number plaque I've been working on is for. 

 

I'm sot sure which I'd rather have TBH.  I'm not set up for (or much interested in) casting jewelry, but on the other hand, big city living is really not my taste either - some of my hobbies don't seem like they'd mix too well with incredibly close proximity neighbours, who would more than likely send the PD and the FD right up my, er, nose, every time I fired up the Black Dread to melt something.  I mean sure, sometimes it'd be nice to have places to go that I could actually walk to...  But I value having a little more elbow room and privacy more. 

 

I guess I'd probably just take the cash instead.  It wouldn't be enough to retire on yet, but I could pay off my debts...  Pretty sure there'd still be more than enough left over to build and equip a nice heated workshop out back too... with a little more elbow room than the 2 cramped and frozen sheds I'm using now.  ::D:  I'd definitely sink some of it into foundry upgrades.  Like a big boy sand muller and a much less pathetically underpowered welding machine, a big air compressor, and a nice big kiln for heat treating stuff and curing refractory and burning out lost wax molds in so I could try some of that...  Maybe even build a small forge, so I could play around with hammers and red hot metal!  Of course then I'd need some really good ventilation too...  OK, now you've got me dreaming about winning the lottery!   ::D: 

 

Kang

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So, 2 weekends ago while it was oddly warm for a mid-January day in Ottawa and my sand was temporarily thawed out, I finally got the mold made up for casting my sister's house number plaque!  There's video on my youtube showing how I made the mold if anyone's interested - I'll link it here.  It also shows how I almost destroyed the mold accidentally gouging a bunch of sand out of the top half of the flask trying to open the mold to remove the pattern...

 

5a6a12b52902a_moldinghousenumbers.jpg.bac9c04140901da43415ba155c860aba.jpg 

 

I decided to keep that mold  anyhow, just means some extra grinding to remove an unsightly lump from the back of the casting later on to clean it up.  If I find I don't like the result, I can always re-melt it and try again, perhaps in bronze instead of aluminum...

 

I wound up storing the mold in my molding bench for a week until I got my chance to pour it just this past Saturday.  I wasn't sure how well it would have kept; greensand molds prefer to get poured right away, but I figured the frigid conditions would help keep the mold from disintegrating once it began to dry out.

 

This seemed to work OK.  Not my very best casting ever, but I think it is usable...  I shot video of melting the aluminum and pouring the mold as well, which I will also link here for anyone who wants to see some fire and molten metal action. 

 

5a6a146742432_castinghousenumbers.jpg.8e604423c88bf182785d591c4f554a0d.jpg

 

I do have a couple of pictures also, for those who don't care about video:

 

20180120_232534-1040x780.thumb.jpg.8b4f2090777175e25673c4c82f440290.jpg

 

IMG_20180120_233152590_HDR-585x1040.thumb.jpg.c92cee4cdbc9aeddcbc050873d4072d2.jpg

 

IMG_20180120_233129872_HDR-1040x585.thumb.jpg.f07e5cc0a64748798f6a043c03230dc8.jpg

 

Looks a little rough around the numbers in places; that is where a bit sand broke off the mold.  Wish I could blame it on letting the mold sit so long, but this happened while I was making the mold and drawing the pattern out of it.  Hopefully once the background is painted a dark colour, that won't be so obvious...

 

Hey, I was reading in an FAQ/guidelines post somewhere how the mods would prefer people link to YT videos rather than embedding, and I've been following that recommendation.  But plain links are so boring... so I got to thinking and figured out a way to use a screenshot of the video embeds as they appear on another forum as a hyperlink to the video, that way the thumbnail appears like an embed, but the video won't load and use up people's bandwidth unless they click on it.  So, all the imagey goodness of an embedded video, but without eating people's mobile data...  What do you folks think about this approach?

 

Kang

Edited by Kang
added 2nd youtube link
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More progress on the house number plaque project: 

 

- Gating has been removed using the new bandsaw

- Edges and corners ground/sanded smooth using oscillating edge and spindle sander

- Raised surfaces roughly hand-sanded (100 grit)

- Spray-painted black

- Paint sanded off raised surfaces

 

housenum.jpg.96654a84851288a4c00e0d48eaf207ac.jpg

 

Still to do:

 

- Upload new edit - click on pic above to see video of all the aforementioned sanding and sawing and sanding and grinding and sanding and painting and sanding. 

- repair scratched paint and greasy fingerprints the kids left on the paint job last night when I turned my back for a second.

- Higher grit sanding of raised surfaces & cleaning up a few little casting defects (pits/pores) as best I can (left edge of the "6", center of bottom border, etc.)

- Seal for outdoor use

- Select mounting hardware

- Send to my sister!

 

Thanks for having a look!

 

Kang

Edited by Kang
added hyperlink to video and updated the to do section
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I cheated a little and used some of my minis tactics to clean up the little dings on the left side of the 6 (silver craft acrylics and a fine tipped beater brush).  Then I sprayed on a few coats of gloss sealer to hopefully protect the shiny for a while when it's sitting on the front of my sister's house.

 

Still have to figure out what sort of surface it is going to be mounted on so I can figure out and buy the proper hardware to send along, but otherwise this is a finished project.

 

20180210_080857-800x600.jpg.11e6eaf6298cdaf53328d39487a346e7.jpg

 

Probably the last casting before the snow goes away - I've officially surrendered in the war to keep my melt/pour area clear - the snow just won't stop!

 

20180209_170254-1-645x484.jpg.18e91e394d714b62ea1600016b27d039.jpg

 

Kang

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Just a quick update to post a close-up of the silver paint touch-ups on the left edge of  the 6:

 

20180210_101138-800x600.jpg.3360603a9e862d89ab1833ad1a0ff826.jpg

 

Kang

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With the melting furnaces snowed in for the winter and the greensand frozen in my molding bench, I need to keep myself busy doing other things to avoid going crazy and ending up on the evening news.  This means extra D&D sessions (Pathfinder actually), plagiarizing a fellow internet weirdo's ingot tongs design, dredging up months-old arguments with my wife as to the existence of possibly hallucinated local woodland creatures (in yo face, Mrs. Kang!), cleverly naming my homemade foundry tools after A Song of Ice and Fire characters, or whatever it takes...  This is what that looks like.  You have been warned.

 

Meet Ser Robert Tong!

 

https://www.youtube.com/watch?v=EwmNFKKvCeQ

tongthumb.jpg.e566094a61b84d0ba069767782be3186.jpg

 

Kang

 

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