TECH- How to SAND CAST Aluminum Car Club plaques at Home!!!

Thanks for all of the great words I appreciate all of it. I'm only 25 never had any sort of shop cl*** in highschool. Didn't even have wood shop, the school got a little pissed when I used the burnout oven for ceramics to melt some metal to cast a frankenstien skull I did in art cl***. Well that just goes to show you where theres a will theres a way. I worked at shops my whole highschool career. Start building cars at 14, just cause its not in school does give people an excuse to be lazy and complacent ...in my humble opinion.
-Thanks,
Chris

 

Very cool I will have to try that. Thanks

 

Pins & Needles, dunno what your day job is but you've definitely got a solid grasp on foundrywork. Awesome job of covering the process and making your own tools & fixtures. Especially like that you're melting with the torch instead of spending days making a furnace. Man, even the correct terms were used.

There's one real, super important thing to add. You need more coverup during pour, even for that little mold. Every now and then the hot metal will ignite fumes from the sand binder inside the mold cavity. And it sorta pops. The pops are unpredictable and sometimes cause it to burp metal. Liquid aluminum sticks to skin and will not bead and roll off.

Great tech post! Great!

 

Yeah, I know there were a few things left to be desired in the safety areas, sorry for that. It was a situation where I wasn't doing the project at my normal location and left a few things behind... such as my leathers and what not. (not to mention my larger crucible...but that I just rolled with and made). I appreciate anyone who notices those things and points them out, in foundry work or any sort of torch work safety it #1, there really aren't any close calls, if something happens and you are not wearing the proper gear the out come it going to be really bad. Thanks again for all the kind words!
-Chris

P.S. I acutally work in the computer industry sitting in a cubicle all day long, That is until I get off then its off to the shop to do what I really love! Hey gotta pay the mortgage in California somehow!

 

This is plain great.
Wont be in the near future as i already have too many things to do, but i sure will put this into practice.
When its gonna happen i will post a tech w/ a link to this one and many thanx to you for the how 2.
Thanx m8, Nick.

 

Heres one I made in my youth.

 

Great post, thanks for sharing!

 

Very educational and a complete joy to read and see the different steps. Thanks so much for taking the time to post your project. I learn something every day on Hamb and thats makes it the best there is.

 

Any material with appropriate draft that will survive tamping will work. Many of the tricks here are for durability. But always make sure your pattern will make at least 3 molds if you need one finished piece. S**** rate can be extremely high during the learning curve.


The bodyman's best friend is also a pattern maker's best friend. Know what a lot of guys use to finish pattern bucks or maintain them? Bondo. That's right, experienced mudslingers are a step ahead of the game.

If dimensions are important, buy a "shrink ruler" for the alloy you're pouring. It's compensated for how the metal will contract as it solidifies and by using it for the pattern, you'll get closer to the bullseye. Notice I didn't say hit it. Foundrywork is as much art as science.

good luck!

 

Pins&Needles, here's your next challenge

http://www.foundry101.com/racert2.htm

Seriously, you appear to have the process down well enough to be doing loose piece molding which opens a world of shapes. Good luck

 

My wife is gonna be so pissed!Now Ill be in the shop all weekend!Damn you!!!!

EVIL

 

Spread it out, real thin, in the Sun, on a hard surface,
to get the water to evaporate. Wind also helps speed the process.

Then check the instructions real close.
Water sounds like a bad idea, if you are casting hot metal.

 

very cool tech,and very dangerous.although,i think the next task i would try is making a kiln to heat the aluminum or what ever you're trying to smelt,and let me say,fumes are really bad.and propane is cheaper than ox and accetalene (did i spell that right?)hmmm,maybe make some sand cores and make some manifolds?think of the possibilities.

 

Was it water-bonded sand? Olivine with a dusting of clay? Or some kind of moisture activated chemical resin?

If it's just water bonded "green sand" then you don't really get it wet. More like get it really humid. Never wet enough to shine. Know the old spaghetti trick? Throw it against the wall? Same deal. Big clump should stick. Grab a fistful, squeeze hard, and when you let go should see your hand's creases perfectly reproduced including some fragile knife edging between the fingers. Your hand should feel humid, but should not have squeezed any kind of water to make spots shiny/wet looking. That's how perfect green sand acts and making it is an art itself.

Chemical bond sand is the only way to go for a home user making small things. The molds are not as time/technique sensitive. Green sand is for economy when making tons and tons of mold sand.

 

This is a GREAT tech thread...thanks for the info. What kept me from doing this was thinking I needed to build a crucible, but your method looks MUCH easier and I have many cast iron pots I no longer use. I wonder if there is a way I could use an old pot belly cast iron wood stove as my melting oven...any ideas? Also, I'm ***uming that you're using Oxy/Acetaline there...am I wrong?

 

Holy ****! you just blew my mind... looks like I'll have to quit my day job, and become a hermit in some shack in the middle of the desert with a water tank, a huge propane tanks and some refractory blocks... Ah that would be the life... all the possibilities!. On a serious note That cup saucer combo is amazing! I've always wondered how to get hollow spot in casting, like that of the cup handle. Is that two pieces in the handle that make up the mold? How do you get the sand to hover in hollow casts? A good example of this is the cast intake logs for early hemis like the wieand drag star?

 

Yes it was a green sand mix that I bought online. I apparentkly read the directions wrong and added too much water. NOt enough that it is shiny or squeezes out but it just never seemed to stick together well enough. It might have been that I did not pack it hard enough. Where did youi get your sand? Again, nice tech article. I took a summer college course and we did lost wax. I have been longing to do it again since. Your tech article certainly helps.

 

Buzznut, here's the beauty of the oxy torch.

When you build a furnace, the furnace has to survive temperatures higher than the melt point of aluminum since it's the source.

When you torch melt in an iron pot, the heat is directed at the aluminum workpiece, not the cast iron pot. The cast iron always has one side exposed to cool temps. This allows you to use a much simpler melting rig.

Seriously, when you get into it, there's plenty of work and trouble just in patterns and molding. Don't feel you have to engineer yourself some kind of production melting process. Foundrymen melt by the easiest way possible, because it's actually a small portion of the overall process. From the outside looking in, melting IS foundrywork. But really molding will make or break you. Good luck!

 

Depending on how large the pot belly stove is you might be able to use it if you can find a bag or two of castable refractory which is kind of like cement but withholds tons of heat. You might be able to use fire brick as well but you'll have to trim it into shape, and it gets expensive. One of the most difficult things in casting is the original buck, pattern making is exhasuting, laborious, and quite honestly very un-satisfying, because once you are done with that you still aren't even half way there yet! I'm definately not trying to put anyone off or convince them otherwise. But all too often I have seen friends want to get into casting spend a whole bunch of money putting together a blaster with white fire brick, all the right propane set ups, and gear, only to get to the pattern making part and loose interest. If you can get through the pattern making part with the correct valleys in the part and the right degrees on the pieces you can definately cast it! My humble advise (as I myself am still a novice) is to keep it simple, start with a small simple piece (such as a finned fuel block off plate or something) and make the pattern! You can definately cast it if you have a small oxy-acetylene set up, and an old cast iron pot. If you have the app***ude for it keep getting bigger until you do what you really want! You can skimp on all of the equipment but make sure you don't skimp on safety gear. I can't stress this enough.
-Chris

 

WOW Coffins?... how original.....

 

Ahh foundry magic.

The secret is the mold is bigger than the part and the cores attach to the outer mold outside the finished casting. So everything is cutoff and the consumer never sees it.

You can also use low temperature "chaplets" to hold a core in place. They're usually little thin pieces of tin or wax or anything low temperature that will burn away as the metal sweeps thru, because the metal's density supports the core at that point.

 

awsome tech man,, one of our guys just stared messing around with that stuff not to long ago,, heres a practice one he did ,,thanks for doing this tech

 

Well in this case, I'm not going to spin my wheels.... I'll use the cast iron pot and torch process as my foundrywork and get right to the hardest part first. I'm familiar with wood carving and have the tools so I'm going to start on a buck as soon as I'm done moving. Thanks again guys...

 

I got a whole kit from a local casting supply house before it went out of business. If you look at the pictures I have a close up of the can in one of them with the name of the business. this is a really great kit for small pieces and the sand is really fine stuff so the casting comes out smooth. If you need to do bigger stuff one of the internet casting supplies probably sells pre-mixed sand in larger quan***ies. I've had problems with the green sand myself pre-mix is the way to go.
-Chris

 

Now this is a great tech !

So now when guys put up plaques that you made for sale , now we see why the price might seem high . There is a lot more work then some might think !

 

awesome...i want to try this now.

 

Wow, wow, wow! This is awesome. Thanks so much for doing this, I hope you win!

 

this is a great post, definately gunna bookmark this and try it soon!!!!

 

Man that looks great Nice Work!

All the work is in the buck/pattern. Once that is done the sand casting part goes really quick and is acutally a lot of fun to do, but there is a reason I don't do this for a living. There is also another way to make the buck/pattern for a car club plaque. It is an acid etch process on a metal (magnesium I think but I'm not sure) plate. I don't know much about the process but I think its much like the way you make name plates. You use mask to cover up the part that you want raised in the end, and then expose the other parts to the acid, which eats away the metal and leaves nice valleys at all of the intersection points. Quite a few plaques are done this way (including the plaques with a lot of writing on them such as at museums). But the letters don't stand off the back as far as you would get with a wooden pattern, and the process doesn't seem like something that can be done at home very easily.
-Chris

 

nice post, but i don't remember getting mine.