Mini Arc Furnace And Small Castings

idbruce

As many of you know, I am interested in the subject of metal casting, however my current setup is labor intensive and is restricted to an outdoor activity. Over the years, there have been many times that I needed a small and simple cast, and furthermore, many times this need occured during the winter months. So occassionally I have been doing a little research on building a small indoor furnace, to handle such tasks. While researching mini arc furnaces this morning, I stumbled across this YouTube video, which caught my interest, and thought that some of you might like it also.

https://www.youtube.com/watch?v=JIlZsuRc9jQ

EDIT: And here is another one of his YouTube videos, which shows other aspects of this project:
https://www.youtube.com/watch?v=VTzKIs19eZE

Heater.

Wow!

I just happen to have a huge old microwave oven transformer here....

Publison

Cool find Bruce. Reminds me of running the carbon arc projector in our High School auditorium back in th 70's.

idbruce

@Heater and Publison

Besides being informative, there are several things that I really like about these videos, but most importantly is the recycling of a couple objects to obtain crucial parts. Additionally, I like the idea of creating two furnaces (crucibles) from one inexpensive fire brick, however, I will most likely store the carbon rods in a seperate brick and perhaps create a seperate furnace for brass, bronze, aluminum, copper, and steel.

Those videos definitely present possibilities.

Heater.

Recycling...ah yes...takes me back to my school days. We were sand casting aluminium in the metal shop using a ferocious gas powered furnace. Can you imaging 14 year old's being allowed to do that in school now a days.

Anyway, between us we needed a lot of ali to cast bases for steam/hot air engines and whatever. All of a sudden all kinds of coat hooks, door handles and rails were disappearing from all over the place.

Let's say it was premature recycling

RobotWorkshop

Do you happen to need any small diameter carbon rods like that? They are similar to the negative rods used in the large WWII searchlights and some of the ones used on the smaller carbon arc lights and carbon arc projectors.

I have some that are too short to use in a searchlight but would work fine for this. Also have some that are longer and were probably for a projector and don't really have a need for those either.

Robert

User Name

Taking apart dry cells for the carbon rods was an important part of my misspent youth. But the heyday of dry cell batteries has long passed. Fortunately there are much better choices. The pic here shows (poorly) what any old Joe (or Dave) can pick up on ebay for a few drachma.

idbruce

Let's say it was premature recycling

Premature recycling..... Yea, there is a lot of that going on New homes stripped of wiring and copper plumbing. They catch those premature recyclers all the time around here. Nice phrase.

"But your Honor, I was not stealing... I was just doing a little premature recycling to make my pockets a little greener"

Ttailspin

Say..What are you guys up too?

http://mad-science.wonderhowto.com/how-to/melt-metal-with-modified-microwave-oven-transformer-0139556/

Phil Pilgrim (PhiPi)

Publison wrote:

Reminds me of running the carbon arc projector in our High School auditorium back in the 70's.

Wow! Your high school was on the bleeding edge for the 1870s!

-Phil

Heater.

idbruce,

"But your Honor, I was not stealing... I was just doing a little premature recycling to make my pockets a little greener"

Ah yes. Of course back in the mists of time and at that place the issue would not have been escalated past the Headmaster. We could have argued:

"But Sir, we were only doing a little premature recycling to support a valuable part of our education here"

No doubt that would have resulted in a severe caning and a week of detention after school. Bet they don't do that in schools now a days either.

Anyway, it was a lot of fun doing that sand casting.

idbruce

Anyway, it was a lot of fun doing that sand casting.

Pouring molten metal into sand and then breaking away the sand to see the result.... Cool stuff. I am sure I would have a lot more fun with it, if I had a special location set up for just casting, and a better furnace/burner setup would be nice also.

For instance, I have been wanting to make this burner for a very long time, but it just doesn't make sense, until I build a new furnace:
http://www.backyardmetalcasting.com/oliverburner1.html

EDIT: And here is the rough draft of my new furnace that I designed many years ago, but still have not made it yet.

frank freedman

Bruce,

Here is a device I used to maintain while stationed on the USS Hoist. (Filthy thing to maintain let me tell you) Maybe get some ideas for the automatic feed of the arc. rods....

http://www.maritime.org/doc/searchlight24/index.htm

FF

idbruce

Frank

Pretty cool document. Thanks for sharing.

prof_braino

I know what we're going to do today Ferb!

RobotWorkshop

If you want a few more details on carbon arcs and how they worked in the large searchlights I have one of the old Sperry product catalogs posted up here:

http://www.searchlightparts.com/searchlights/wp-content/uploads/2014/03/SperrySearchlightCatalog.pdf

They are pretty cool to see running. The GE had a more elegant method of controlling the negative feed with a dual magnetic clutch and is a bit more tolerant to voltage drops than what Sperry used. Otherwise they work the same. They keep rotating the carbon so it burns evenly. I don't think many of the regular arc lamps did that...

Robert