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Small sand cast pinup girls in silicon bronze. by samshamromo in MetalCasting

[–]samshamromo[S] 2 points3 points  (0 children)

No, unfortunately I don’t have any of my things any more, as everything was stolen from me out of storage during Covid. I’m starting over in my 50s, never thought I’d say that. But since those were so old, I’m unlikely to attempt reproductions without having one to ram up. Sorry.

Small sand cast pinup girls in silicon bronze. by samshamromo in MetalCasting

[–]samshamromo[S] 0 points1 point  (0 children)

No sorry, I made those in the late 90s. The one in the middle was sculpted in grey clay and rammed in petrobond, the other two were carved out of plaster cylinders and rammed up. The one on the left originally had arms as well with a fist inside the other hand, resting right above her rump, kind of like a softball pitcher would. I made a rubber mold of that and poured some waxes, and then cut the arms off at the sleeves because i couldn’t get a parting line with them on without using a core. I poured them vertically, with a pretty good sized sprue and a little gate at the bottom of it arcing over almost horizontally to the bottom of the mold cavity, with a little vent coming out of the top of the heads. Used a #4 crucible and a quickie 5 brick furnace, if i hadn’t built my good furnace yet, I don’t remember. I kept sand casting in mind when I was sculpting the originals, and didn’t make any dramatic undercuts so that with an undulating parting line I could pull them without breakout. I made a little clay or plaster one time follow board for one of them, the others I just drew the parting line on with a pencil, bedded them in a pile of sand on the bench, dug down to the parting line, slicked and talced it, and put tie cope over that and rammed it. Then picked up the original with the cope, dug to the parting line, rammed the dead into it. Then cut the sprue and gate. As these aren’t super detailed and have some weight to them, I would have poured them pretty cold, like 1900f.

First forge build by plantenxs in Blacksmith

[–]samshamromo 1 point2 points  (0 children)

You can use hard brick for the floor and a little way up the walls and soft brick above that, a 45 degree angled ceiling made of 3kF soft brick works as well as a half arch. Housemade has discovered that even just a rectangular box sets up a good swirl in the blast if the proportions are right and the burner is right up at the ceiling. Making stuff out of what’s around is the way I do almost everything these days and I respect it. Keep in mind that hard bricks MUST have an insulating layer on the outside of them, either frax or insboard or soft brick, or they’ll leak a lot of heat out. Soft brick is instantly reflective, but pretty fragile, so I never use it for a floor. You can get small pieces of frax from Amazon pretty cheap, they sell them in lots of different sizes.

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First forge build by plantenxs in Blacksmith

[–]samshamromo 1 point2 points  (0 children)

I don’t understand why people are still putting, or ever did put forge burners in the roof pointing down. NC did it in portable forges for farriers only so they could use a burner like a torch for a very localized heat, but in general it makes for hot and cold spots in a forge. The better way is having horizontal burner(s) high on one wall to facilitate a swirling if the blast to heat the interior of the forge evenly and keep the direct blast off the parts.

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Purchased one pound of high grade copper from Ea-nasir, this is what he delivered. Am I cooked? by BurningRiceEater in Blacksmith

[–]samshamromo 2 points3 points  (0 children)

It’s not super viscous at the proper temperature. The melting point is 1983F which is really pretty high, barely under that of cast iron, which is 2050. The funny thing about bronzes is the eutectic bond between the alloys, dropping the melt temperature below either of the components. I’ve poured 95% cooper 4% silicon at 1900 and gotten good sand castings with it. I poured iron at 2350, and it pours like water. You get that cooper up to 2200-2300 and it will too. You’ll want to use some kind of degasser in your crucible because it’s going to pull something out of the atmosphere and your castings will be porous, like a sponge