Bronze Hands Lost Wax Project

Ohio...

 

I found the video I was thinking of it's: Anchor Winch Rebuild - Part 10 - Plaster Block Mold Bronze Casting - Got One

 

I made one of those but haven't had a chance to test it on my burnout kiln. It is definitely on the list.

 

I was super close to winning with Stullers. They have a service which you give them your wax model and they will cast it for $20 + the cost of the metal grain but they only do precious metal and they won't use outside grain.
The university professor that deals with metal working & jewelry said they only do small jewelry scale casting but he directed me to the professor in charge of the sculpting department. He also said they have a ceramic mixing machine, so I sent her an email. Hoping to hear back today from her.

i'm nearly done with the rubber coating... i've got the fingers secure, and i'm going to do one more coat over the entire model to make it smooth. then onto the plaster mother mold creation!
lets go!

 

Sitting here at stullers looking at one of their catalogues and see that they have silicon bronze listed. I may try to call again and see if they’d do it in pure silicon bronze. The lady I talked to yesterday obviously wasn’t familiar enough with their stock grain.

 

If that price is by pound that’d be pricey. prol around $400. But the cost to have a company create and cast something like this was around 5-10k last i checked so it could be an option as a last resort.

at least the ultravest 50lb box only cost me $55.

 

If you still need bronze, check out this thread..
http://forums.thehomefoundry.org/index.php?threads/bronze-lancaster-foundry-supply-co.908/

 

Good news I'm just waiting on the wax to come in and the rubber mold is pretty much done now. And best of all I was able to find a pottery casting shop in town that will fire cure my block mold for $50 once it's done. Also I was able to pick up a 50 pound box of casting mold material from Stuller's this morning so besides the wax I'm almost ready to rock.

 

Cool. I'm interested to see how it turns out.

Usually molds are poured into when hot so the metal doesn't touch cold mold material and freeze on contact. Might not be an issue since your hands are not very thin and twisted so the metal won't have far to go before solidifying.

You should try cast into the mold as soon as it is finished firing because it will start absorbing moisture from the air immediately on cooling down. It will chemically bind moisture out of the air like one of those drying agents.

 

Thanks for the tips, zap.
With that in mind ill try to cast as soon as it’s done, but just to be safe I’ll prol wrap it up in a contractor trash bag to keep moisture out.
Also in my largest forge I should be able to heat the block up without a direct flame. I won’t try to heat it up to the same temp as the bronze but getting it higher than room temp should at least help prevent insta-freezing.

 

A good friend of mine came over the other week and was taking a look at my process. He noticed that I didn’t have a crucible large enough to fit all 20 pounds of bronze so he kindly ordered An extra large crucible for me. It amazes me how many people are pitching in to make this happen

my basic mother mold is done and drying. I’ll be firming it up with mesh wire and POP powder tonight. Then I’ll be able to take the hands out of the rubber mold. praying there’s no glitches at this stage. Still waiting on my wax to come in. Wish they had given me a tracking number but at least I know it’s in transit.

 

not sure where in Ohio silly train is at. But there's a couple of kilns listed for sale on FB market place in the Notheast of Ohio (near me) for $325-350. Two months ago you could find them everyday for $100-250. Must be a seasonal thing

 

I'm in Louisiana crazybillybob. but thanks for checking!
that seems like a steal David! do it!

 

I thought you were posting Ohio laws .... just assumed Sorry about that

 

Zapins, i know you've done alot of work with spruing. Do you think i'll need to add sprues to my bronze hand wax model? or do you think the width of the wrist openings and fingers will be enough without sprues?

my plaster clamshell didn't quite work out the way i wanted so i scrapped it and put two more layers of rubber. i did one more layer of the rubber molding that i've been using, and then all i had was some liquid latex, so i put a decent coat of that over the top and that's drying now. i should be ready for demoulding tonight.

 

I think the hands will be fairly easy to cast with minimal spruing. I'm guessing you're going to hollow cast these? I'd add 3 large square shaped sprues to the base of the arm. Make a tripod over the opening in the wrist and add a large pouring cone to the top of the tripod.

I'm not sure how thick the walls will be of the arm but your sprues should be about 30 to 50% bigger than the wall thickness it is feeding and the pouring cone needs to be fairly large to ensure enough material is there as a reservoir to feed the arm as it cools. I'd make the sprues about 3 inches long so the base of the pouring cone is about 3 inches above the arm hole.

You'll be pouring the arms separately right?

If you do a solid arm (waste of metal) then you'll need to add a very large and tall sprue to the bottom of the arm. Maybe 8 inches tall and 3 to 4 inches wide to ensure it fills solidly. The metal will pull a void in the center if the sprue isn't tall enough. It can pull the void quite far into the piece, just a pure hole down the middle usually many inches long. Also unpleasant to grind off this kind of sprue when finished. I had to do this on my octopus and it was not fun to clean up.

 

No, I’m going to solid cast them. It’ll just be from the wrists down. With that in mind do you still think spruing is necessary?

 

If I cast my own hands, my guess would be each would be over 5 pounds. If you are giving this to someone who is elderly, weight might be an issue.

 

If you solid cast them you'll need that 8 inch tall by 3x3" sprue or you'll get a big casting defect running down the middle like I mentioned above.

Why not cast them hollow? Its roughly the same prep.