Are You a From Casting Builder?

[cfellows]

This is an intresting topic. Has anyone here made your own engine castings from scrap metal?? If you have please tell me about your experience since I find the idea of making a steam engine from absolute scratch fascinating.

I've done some casting although not a lot. Aluminum is pretty easy to cast, requiring furnace temperatures on the order of 1500 degrees F to melt and pour. Zinc / Aluminum alloys, typically called ZAMAC melt at even lower temperatures, around 900 - 1000 degrees F. I've used an 88% zinc / 12% aluminum alloy that yields a metal that's reasonably good for flywheels since it's only a little lighter than cast iron. I've never tried Brass or Bronze since those both require temperatures more in the 2000 degree F range. And of course, cast iron requires temperatures of about 2700 degrees F.

There are lots of home foundry sites on the web and several casting forums on Yahoo Groups.

Chuck

 

[robert1352]

Thanks for the info Chuck. Did you make you own foundry ?? If so was it terribly difficult? Also, what other problems did you encounter that you didn't expect? Did you use sand for the molds? Thanks again, Robert.

 

[Powder keg]

Did you make your own alloy? did you melt the aluminum first then add the zinc? Please explain?

Thanks, Wes

 

[cfellows]

Thanks for the info Chuck. Did you make you own foundry ?? If so was it terribly difficult? Also, what other problems did you encounter that you didn't expect? Did you use sand for the molds? Thanks again, Robert.

Building your own foundry furnace is not terribly difficult. Basically, you start with a container, like a large coffee can, popcorn can, 5 gallon bucket, etc. They can be powered by electricity, charcoal, or propane. I would refer you to one of the following sites for more detail:

http://metalcast.boorman.us/foundry_1.html
http://myhomefoundry.com/
http://www.backyardmetalcasting.com/

I would also caution you to read and observe all the safety concerns. A quart of molten aluminum has a lot of stored up energy and can cause devastating burns if it gets away from you.

For the molds, you can buy oil based casting sands or you can make you own from silica sand, water, and a few other ingredients. Again, the above sites have more information.

Chuck

 

[cfellows]

Did you make your own alloy? did you melt the aluminum first then add the zinc? Please explain?

Thanks, Wes

Wes, I did make my own alloy. I had some zinc bars that I had picked up on ebay. I just put the zinc and the aluminum pieces in the crucible and melted them together. One variant of the alloy is also called pot metal, which is used in a lot of products. Unfortunately, pot metal isn't viewed as a very strong alloy, but the problem is that it's usually cast in a very thin cross sections which makes it weaker.

Chuck

 

[Powder keg]

I have a bunch of zinc. Were those measurements by weight or volume? Probably weight:O)

Thanks, Wes

 

[cfellows]

I have a bunch of zinc. Were those measurements by weight or volume? Probably weight:O)

Thanks, Wes

As I recall, it was by weight. If you Google ZAMAC, you can find info on the different alloys at a number of sites. ZAMAC, as listed by the various sites, also has other traces of elements in it. However, I just used aluminum and zinc and it worked fine.

Chuck

 

[robert1352]

You are a wealth of information Chuck. Have you ever tried to melt iron? Best regards,Robert.

 

[cfellows]

You are a wealth of information Chuck. Have you ever tried to melt iron? Best regards,Robert.

No, never tried iron. Iron requires temperatures in excess of 2700 degrees fahrenheit. Also, you have to use Silicon Carbide (expensive) or fired clay (easily broken) crucibles to melt it in whereas you can use homemade steel crucibles for aluminum, zamac, or bronze.

Chuck