u/Doubledot_dot

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So here is my third attempt at casting. And my first successful casting with my homemade investment.

This is a horizontal door bin pull for my cabinets.

Yesterday my first recipe of plaster and refractory materials ended up too wet. It cured anyhow but cracked on the burnout. I tried to use it but molten metal dropped out the bottom.

I suspect maybe it was the silica i was adding and some quartz inversion hullabaloo.

I was trying to match prestige oro. Although i used the same weight to water ratio mine was like pancake batter not sour cream.

My thoughts were that I was using pure alpha calcium sulfate hemihydrate, which doesnt demand as much water as beta calcium sulfate hemihydrate. Hence why so runny.

Also i wanted to just get rid of silica altogether.

So i adjusted the recipe to include some of the beta via regular pottery #1 plaster, to end up with a water need matching prestige oro, or just under. Replaced the silica with some alumina oxide and added a bit of wollenstinite w30 for some crack resistance. Using some mulcoa grog and the zircomax as the other refractories.

I made two recipes, one with a high load of zirconium from the zircomax plus. I used that and dipped my wax and sprue in it and vacuumed it just by itself to suck it down onto my cast.

I added the second to top off and vacuumed in between each time.

After two hours i put it in the burnout oven with another two hour 65C hold before activating the staged and ramped burnout schedule

While cleaning it up i dropped it and knicked one of the antlers. Oops. That didnt take long. At least i can make another.

This has been a very fun rabbit hole. I wanted to have some location specific brass cabinet hardware for my kitchen cabinets I am building. So why not cast the hardware?

I have a bunch of electrical copper wiring, so I stripped it, and melted it down into bars.
I got some ferrosilicon 95% si content, some Manganese.

I'm targeting 3.33% Si from the fesi95, and .9% Mn, with just a dash of .25% Ag from some scrap sterling.

I picked up an elegoo saturn 16k ultra, and some Siraya royal blue casting resin.

Some fiverr help from a talented jewelry designer - shout out to Sohail, fiverr doesn't have the best rep but there are some genuine people wanting to help and he is one of them. He got me through the worst of the 3d design.

Printed my cabinet knob as two pieces, the face, and the stem. Used a bit of wax to attach them.

Put the knob on the sprue, sprue into the rubber base. Taped up the flask, invested, burned out over 12 hours with ramp using a cheap machine from aliexpress.

I made a vacuum casting setup from a vevor stainless chamber with an acrylic lid. Cut an oversized hole into the lid, placed a wood block with the flask sized hole in it with a channel for a silicone and graphite gasket stack. It doubles as a investment gas pull with a block off plate where the flask sits.

When I poured into the flask I thought it failed and solidified before the metal reached the knob. There was no where it sucked up that much metal that fast, but it did.

Vacuum pump made a screech when it pulled hard trying to pull the metal through the investment.

Overall I am happy with the first attempt at all this. The undercuts and shadows on the morning glories read well I think. Mt Hood to me shows exactly as it should. the flower and vine detail on the stem is exactly what I wanted.

It is heavy. I see lots of room to be better. I shorted the investment amount and had to go for a second top off, I think that's what made that flashing right at the face. a few bubbles got trapped behind the stem, I'm thinking a vibrator on a plate that the vacuum chamber is on so i can get a pull on the bubbles and jiggle them loose at the same time.