Bronze Hands Lost Wax Project

Fritz had this video on the subject of shell creation:

 

Thanks for the tips Jason! I've been trying to do wax casting in algenate but after looking at some silicone mold making videos, i bet that would work WAY better. i swear i'm going to be a pro after failing this many times. XD

 

You'll get it. Keep trying.

 

Can't agree more with Jason. He's spot on with wax comments as usual. The molds are strange. I think they have some kind of natural oil layer in the rubber that either helps or interferes with making wax copies. Not sure why and I haven't investigated fixes for it. It does however cause bubbles to form in the surface of wax castings.

Much easier to fix the waxes as you want when before having to chase it all in metal. You need expensive tig welders to repair mistakes in bronze.

Alginate molds are one time use and I doubt they can be used to make hollow castings.

I'm not familiar with the device you got to cure the plaster mold. Will be interesting to see what happens. It is important to get plaster up to a hit enough temperature or the moisture that is chemically bound to it won't be removed. It's not the same as moisture that surrounds / saturates/ makes plaster feel wet to the touch. Its bonded chemically and can only be removed at a specific temperature not by blowing dry air on it.

 

Thanks Zap.. Once that oil layer or whatever it is wears off, it's always been smooth sailing for me.

 

Thanks for the tips guys! The silicone mold worked famously. I ended up solid casting the hands in wax and then coded out the wrists/palms with a drill since those were the thickest parts. The hot air gun should get it to the temp it needs to be. I’ll use my new high temp laser thermometer to make sure that’s happening.

 

Quick question about degassing with a vacuum chamber. Do you degass before you set your wax into it or after?

 

You arent degassing the wax.. You degass your liquid investment before pouring it. Then you pour it around your wax part and degass it again. Next time the vac pump is used is when you pour metal. Investment is pourus so you pull a vacuum on it and dump in the metal.

 

Still not dead yet!! I’ve been steadily working on the project plowing through setback after setback. Learning curve’s an expensive teacher.
I built my own vacuum chamber, block mold casting box, and welded together a metal crucible pouring frame. So I’m completely ready for my next casting attempt. Last night was my first attempt at an actual pour. My block mold had a crack in it but I decided to pour anyway just for kicks even though I knew it wouldn’t make a final product. And it leaked bronze after I poured as expected.
I know what happened to my block mold though. My setup uses two high temp hot air guns that can go up to 1300F and the gun that heats from the side was accidentally set at max temp at the beginning for several hours before I discovered the error which cause uneven curing temps leading to the crack. I’m pumped at the results though for the fingers that actually came out. Amazing detail down to fingerprints!

I plan on a second cast in about a week and a half after I get back from traveling for work. I’m ordering all the extra supplies I need today so it’ll all be in by the time I get back.

I also wanted to share about the supplier I found after extensive research for everdur. They charge $6/lb
16.50 shipping for orders weighing between 4+lbs-35lbs
Clay-planet.com
Instead of ordering online it’s best to call them to order a specific weight ingot over the phone.
(408) 295-3352‬
I got a 9.5lb ingot for $70 including shipping.



thanks again for all the advice and tips!!

 

Remind me what investment material you are using... One tip with investment, it is highly recommended you use distilled water for it and always follow burnout temps and times to the letter until you gain experience with it. You cant know how sweet victory is until you've had a mouthful of failures.

 

I’m using R&R Ultravest. I had the same thought and did end up using distilled water. A friend of mine who works for a fertilizer company is trying to get me some deionized water to take it to another level. Besides the snafu of the wrong temp for my heater I think I may have made the block too narrow so I’m going to make it thicker this next go around.
ive got plans in the works to build a diy electric kiln. Just need to research wiring it up and get my best friend who’s an electrician to come wire up a dedicated 220v outlet for me in my garage to properly power it. Then I can move from rednecking it to proper temperature control in the future.

 

Lancaster supply in lancaster PA is around 4.10 per lb with 16.50 shipping.

Good details man. Very encouraging. The crack and drainage are easily fixed.

 

If ya look around here, There is a thread on setting up a PID. When you want precise control of your burnout schedule, they are worth it big time! I went with Auber instruments for my PID. Super easy to control your kiln.

 

See this thread on how to contact them:
http://forums.thehomefoundry.org/index.php?threads/bronze-lancaster-foundry-supply-co.908/

 

Thanks for the link! I’ll have to order from them next time!
I really think by fixing my error on the uniform curing time and then making my block mold alittle thicker in girth I’ll be seeing my first successful cast here in the next two weeks.


I’ll start another post to discuss the electric kiln build. I’d love some extra input on the project from you Jason since you’ve already gone down that path before. I’d rather learn from others and avoid the pain of mistakes when and where I can.

 

I havent had to scratch build a kiln yet, but it's a no brainer. The guys here helped me get the pid squared away. It's not hard. Kelly is the electric kiln builder. I just buy kilns that reek like cat piss.

I have to ask.. When you poured your bronze, did you have the flask under a vacuum??? Also, what temperature was the flask at when you poured metal into it?

 

I didn’t even know some people pour while the flask is vacuumed. So no lol.
I had the flask up to about 1000F. One of my heaters went our after I had it cured so that’s as hot as I could get it before the pour.
I knew the crack would fail but I had poured some anyway just to get an idea of what details would look like. Attached is a gif of my redneck cast attempt.
Http://imgur.com/a/isE7F2i

 

it's not some people.. its everyone with a flask. watch some jewelry casting videos. ya see, that investment is gas permeable and by sucking on it while pouring gets the metal everywhere it needs to go.

 

I’ve seen the centrifuge jewelry casting, but I didn’t realize those centrifuges were vacuum sealed.
I could understand the need for that with the tiny intricate details and low mass of jewelry molds, but with the volume and weight of the size I’m doing do you really think that’s necessary?

 

Yeah a vacuum process won’t be feasible for how I’m doing it since I’m not even using a flask. But that does give me some ideas of how I can put some steel bands around the block before the burnout cycle to help hold it in place and I may even try to rig something up to make it easier to transfer from the kiln to the pouring station.