Stuff I made in metalcasting class...

Post all your artwork here!

Moderator: Moderators

Post Reply
Message
Author
User avatar
Alibi
Merchant
Posts: 163
Joined: Mon Oct 06, 2008 12:07 am
Location: Joplin, MO

Stuff I made in metalcasting class...

#1 Post by Alibi »

I guess making stuff out of metal counts as art? Mods, sorry if this is the wrong forum :?

So this past semester I transferred to a new college since my last one... well.. it sucked to put it lightly. Their engineering program was a joke. Anyway, so I'm going to a new school in Pittsburg Kansas (about a 40 minute drive one way) to work for a Manufacturing Engineering degree. One of the main things I really like about this school when I considered transferring was the fact that they had a really, really nice building and equipment. There are several rooms dedicated to the metalcasting department alone: melt lab (couple of furnaces, piles of sand, scrap metal piles, boiler/autoclave, oven, etc.), investment casting lab (sand for slurry, mixers, wax melting equip), a wax injection lab (dies, injector machine, cleaning instruments, etc), a finish/part prep room (grinder, cut-off wheel, band saw, files, etc), a storeroom for patterns and matchplates, and of course a classroom. My old school... had... um... the classroom and that's about it.

Anyway, part of the class was a lab where we got to play with melting metal and study various casting methods hands-on. I thought it would be neat to take some pictures along the way so I'll share some of what I did here. In the end, I had to pay for 9 pounds of aluminum for all the stuff I brought home (mostly from the 13 ice cream scoops I made for x-mas presents :P ).

I'll start with what I have the least amount of pictures for and then work my way up... (some of the pics are cell phone pics = fuzzy)

First is the basic cope/drag green sand molding. The general idea is you have a pattern, compact sand around it (green sand means it has moist clay mixed in to make it stick together), pull out the pattern, and fill the hole the pattern left with molten metal. Its fairly easy to do as long as the part is relatively flat. My first part didn't turn out right since there was too much moisture in the sand (moisture plus molten metal = kablooey) but the next part came out pretty well. I made an alligator nutcracker out of aluminum. I made two of them using different methods but I only kept the one that I used the match-plate because the finish was much better since the parting line was pre-made on the plate.

Image
Image

Next we worked on Evaporative Foam, AKA "Lost Foam" where a part is cut out of Styrofoam, coated, sunk in a container of sand, and then metal is poured in which melts off the foam and fill in the cavity left behind. The coating is to protect the surface finish of the foam from the abrasiveness of the sand. Since we used standard foam the surface finish is kinda crappy since the sand filled in the large pores of the foam.

JUST FYI, most engine blocks are made this way. GM actually donated a cast block and a foam pattern to the school. I should have gotten a picture of them come to think of it... maybe once school is back in session.

Anyway, I didn't get a pic of the part in form form but here is the tree just after being pulled out of the sand. The brown chunks/residue is from the coating:

Image
Image
Image

And then the whopper project was investment casting. I made 3 trees worth of ice cream scoops to give away as presents for x-mas plus a tree of random stuff (a sculpture and some coasters).

First the die must be sourced and coated in release agent:

Image

Then its clamped in the wax injector. Too much pressure or wax will make it shoot out...

Image
Image

Then the parts are removed from the die and allowed to cool. Pictured is a wax tree along with parts:

Image
Image

The parts are then attached to the trees with molten wax, a ceramic pour cup is added to the top, and the tree is dipped in a ceramic slurry and then coated with a fine sand for the first few coats and later with courser sand to build up the strength of the final shell:

Image
Image

After the shells are thick enough (about 6 coats), the are put into an autoclave at 100 PSI and 150* F to melt out the wax:

Image

After which you get a big pile of ceramic shells:

Image
Image

Now the shells have to be "cured" in an oven for 2 hours at 2000*. The can then be removed but the metal must be poured in immediately before the shells lose their heat (hot metal + cold ceramic = kablooey).

Image
Image
Image

The metal is allowed to cool (which takes longer than sand since the ceramic insulates heat better), the ceramic is chipped/hammered off (outside in the cold and snow/ice too):

Image
Image

And the parts are cut off the tree and set aside for finishing, at which point I ended up with these:

Image
Image

These ice cream scoops are destined for x-mas presents but I need to polish them first.... anybody know how I would go about doing that?

In the end my 9 pound haul was this:

Image

Investment casting:
-13 ice cream scoops (someone threw a couple of theirs into my pile)
-3 coasters (but someone stole 2 of them! Grr! :( )
-One....erm... "artistic" sculpture that would make my momma blush to post it so I'll just provide some links here in a bit)

Lost Foam:
-Pac man
-Ghost
-random skull thing

Green Sand:
-Alligator nut cracker (doubt the aluminum would hold up well though)

For this kind of hands-on learning the 40 minute drive to my new school is sooooo worth it :cheers:
-Eric Avatar Awesomeness Compliments DrMcNinja.com :D

Natani x Keith Fan :D~

User avatar
avwolf
Templar Inner Circle
Posts: 7006
Joined: Wed Jan 17, 2007 5:33 pm
Location: Nebraska, USA
Contact:

Re: Stuff I made in metalcasting class...

#2 Post by avwolf »

That is really cool, Alibi. And a really interesting set of processes. I didn't realize how involved some of them are, but that's an amazing end product. Well worth all the effort.

Oh, and unless I'm greatly misinterpreting the intentions that Sage and Tom had with this thread, your post here is totally fair game. Unless Sage posts differently, you're safe in my book. ;)
Image

User avatar
[Yokel]
Grand Templar
Posts: 2047
Joined: Tue Dec 02, 2008 9:49 am
Location: Brisbane, Australia.

Re: Stuff I made in metalcasting class...

#3 Post by [Yokel] »

I gotta agree, that was a really interesting look into casting proccesses. Where else would I have learnt all that?
And tops work Alibi, I'm probably most impressed with the Alligator Nutcracker, but I bet those scoops are going to be handy this holiday season...
Go vertical.

User avatar
Cupil
Templar Master
Posts: 456
Joined: Fri Apr 11, 2008 8:15 pm
Contact:

Re: Stuff I made in metalcasting class...

#4 Post by Cupil »

The process was very informative, and it's always cool to see the kind of effects different materials will have on the process and/or end product.
I really like the crocodile nutcracker, I think I'd also use it for non-nutcracker stuff like. . . I don't know, maybe put something in its mouth to hold?
How light are the ice cream scoops?

User avatar
Neko-Maya
Council Member
Posts: 502
Joined: Fri Dec 19, 2008 2:34 pm
Location: Finland
Contact:

Re: Stuff I made in metalcasting class...

#5 Post by Neko-Maya »

Coooolll! :D really nice work! I like it when someone can make art from metals and such x3
And you even post some steps from the working, I like it, its fun to see how something is actually done. I envy you for your skill. hehe.
HI, I'M NEOTHETA. BLUBBLUBBLUB and I'm inactive here!
DeviantArtFuraffinityWebsite

User avatar
Alibi
Merchant
Posts: 163
Joined: Mon Oct 06, 2008 12:07 am
Location: Joplin, MO

Re: Stuff I made in metalcasting class...

#6 Post by Alibi »

I do a lot of step-by-step stuff on my car forums so I'm used to taking pictures :D

I wish I had thought to take more, to be honest. Theres really some neat stuff that can be done with casting even with home-made foundries. I ran across a site a while back where a guy developed a way to melt down pennies (1982+ were mostly Zinc) in a pretty easy way to make little custom parts... I'll have to see if I can find the link.

Figuring out the runner and gating system is an art form in of itself. There are calculations to reduce turbulence, keep metal flow velocity the same from the front the back of the part, trap trash in a well, etc. Theres also using risers to feed shrinkage of the castings since the metal cools so much to freeze that it needs extra material. Heh, maybe I'll scan a couple of the worksheets in :P

Heres a screenshot in Catia of a mock-up for a part I did for an assignment:

Image

Well, I still owe you guys some pics of the sculpture I did. I actually have a wax mold here at the house still so I can use that to compare against the metal piece. The wax part should be just a hair bigger since the aluminum would have shrunk some (about 7%) but its not all that noticeable.

I'm not sure what I'm going to do with the alligator yet... It will probably just sit on my desk somewhere, maybe with some pens in his mouth. The pacman and ghost are going to get painted and glued to a board so I can hang it somewhere to enhance my nerdiness :D
-Eric Avatar Awesomeness Compliments DrMcNinja.com :D

Natani x Keith Fan :D~

User avatar
Alibi
Merchant
Posts: 163
Joined: Mon Oct 06, 2008 12:07 am
Location: Joplin, MO

Re: Stuff I made in metalcasting class...

#7 Post by Alibi »

As promised, here are some pictures of the sculpture I cast. I did not make the original mold (some art student left it behind several years back), but I did make the wax pattern, cleaned the pattern, attached it to a tree, dipped the tree, and poured the aluminum so in that respect its my piece now.

Um... the sculpture is of a naked lady so I don't know if that's a no-no but considering it is "art" and this seems to be an open-minded board I'll post the pictures in their full glory :P If its an issue, I can remove the image tags.

It took me a bit to figure out how to take pictures of a shiny piece of metal and not get too much reflection before I remembered that I could use a wax pattern to help compare. The pattern I used for the aluminum piece was dropped and I had to "glue" it back together (with molten wax) so its kinda funky but I kind of like the lines in it.

Anyway, on to the pictures:

Image
Image
Image

And I just couldn't resist |D

Image
-Eric Avatar Awesomeness Compliments DrMcNinja.com :D

Natani x Keith Fan :D~

User avatar
[Yokel]
Grand Templar
Posts: 2047
Joined: Tue Dec 02, 2008 9:49 am
Location: Brisbane, Australia.

Re: Stuff I made in metalcasting class...

#8 Post by [Yokel] »

You had to go ahead with the last picture, didn't you... hehe.
Go vertical.

User avatar
Alibi
Merchant
Posts: 163
Joined: Mon Oct 06, 2008 12:07 am
Location: Joplin, MO

Re: Stuff I made in metalcasting class...

#9 Post by Alibi »

Hehe... what else could I possibly do with two identical naked lady statues? :P |D
-Eric Avatar Awesomeness Compliments DrMcNinja.com :D

Natani x Keith Fan :D~

User avatar
[Yokel]
Grand Templar
Posts: 2047
Joined: Tue Dec 02, 2008 9:49 am
Location: Brisbane, Australia.

Re: Stuff I made in metalcasting class...

#10 Post by [Yokel] »

Good question. If anyone has an answer, chuck it on a 3X5 card and mail it this way, would you?
Go vertical.

Post Reply