How would you core this?

Home enthusiasts discuss their Foundry & Casting work.

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Adirondack
Posts: 410
Joined: Tue Aug 23, 2011 6:59 pm
Location: southern CT

Re: How would you core this?

Post by Adirondack »

Sooo... Here's where the pattern stands. I completely redid it for more accuracy and detail. Shown here is 1 1/2" scale, but I can print it out here at the shop in any scale up to 5". The geometry around the legs and feet was a BEAR to get right.

Chris
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harp print 1.5 inch scale 5.jpg
harp print 1.5 inch scale 6.jpg
harp print 1.5 inch scale 3.jpg
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UPRR harp stand 2.png
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RONALD
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Joined: Sun Oct 26, 2003 7:27 am

Re: How would you core this?

Post by RONALD »

Looks great!

Here is a lot of info on using ceramic slurry if you view many of the videos shown on the right : https://www.youtube.com/watch?v=nVZ2PeUd5tw

I did my ceramic slurry work at the local junior college art department, there were lots of older adults enrolled in that evening school sculpture class.

I did RR parts, no need for sculpture; investigate what the local schools are doing.

I did my patterns in foam, most were working in wax, some of my molds have been cast others still wait to be poured.

Being ceramic they will be around for a loooong time.

That big shell mold is for an actual full size bell frame, it will be poured eventually in A319 Aluminum.

I did aquire a good size burn out oven as seen in the last photo.
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Adirondack
Posts: 410
Joined: Tue Aug 23, 2011 6:59 pm
Location: southern CT

Re: How would you core this?

Post by Adirondack »

RONALD wrote: Sat Jan 29, 2022 6:29 pm Looks great!

Here is a lot of info on using ceramic slurry if you view many of the videos shown on the right : https://www.youtube.com/watch?v=nVZ2PeUd5tw
Thanks Ronald. This info on the slurry process for investment casting seems very interesting. How many coats did you find that you needed for good coverage? It certainly seems less wasteful of the investment than the typical process. I've been using SILK from the UK and it is not inexpensive.

This video was suggested after yours, and it seemed helpful as well. https://www.youtube.com/watch?v=W951-Aj6DkU

Thanks for sharing.

Chris
Adirondack Car & Foundry
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A little locomotive with 4 wheels on the track is a lot more fun
than a 1/2 finished one with 16 wheels on the bench!
jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Re: How would you core this?

Post by jscarmozza »

Ronald, this incredibly horrible casting was actually a success! I'm going to try to develop the lost foam technique that you've obviously mastered. I spent all of 5 minutes hand carving a piece of white styrofoam packing with a Dremel and burr ball, then dipped it in paraffin wax to smooth the surface and to fasten the sprue. When the wax hardened I dipped it in a fire clay slurry, let it dry for a few days, packed it in dry sand and poured it in aluminum. I know it's ugly but the pattern was ugly to start with, I was surprised that it came out as well as it did with the materials I had laying around. Now that I have a rough idea about the process I'm going to invest in the proper materials and see if I can hone the skills.
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