Show Us Your Foundry!!!

Home enthusiasts discuss their Foundry & Casting work.

Moderator: Harold_V

Too_Many_Tools
Posts: 27
Joined: Mon Jul 31, 2006 3:25 pm

Show Us Your Foundry!!!

Post by Too_Many_Tools » Fri Mar 30, 2007 9:22 pm

I would like to set up a home foundry and am looking for ideas.

Could you post a picture of your foundry setup?

I would like to make my foundry mobile so it can be stored between runs.

Thanks

TMT

4catmom

Post by 4catmom » Fri Mar 30, 2007 9:59 pm

TMT,
Here are some pictures of my setup. I use charcoal in my furnace and have cast aluminum, brass, and iron. The casting shown is for a steam-powered water pump and is brass. The blower is an electric leaf blower. The sand is petrobond, an oil-bonded sand.
Attachments
Furnace_A.jpg
PumpCasting.jpg
Last edited by 4catmom on Fri Mar 30, 2007 10:15 pm, edited 1 time in total.

4catmom

Post by 4catmom » Fri Mar 30, 2007 10:09 pm

Here's a picture of my molding bench and a finished mold. Basically it is a sheet metal pan about 30 X 40 inches sitting on top of the table saw. The pan keeps the molding sand from falling on the floor. I break open the poured molds into the same pan, then pour the sand back into the storage containers for the next session. The "muller" is a 1/2 electric drill with a drywall mixer. Also shown is the patterns attached to a "matchplate". Kind of a misnomer in this case because it is a one-sided pattern, therefore nothing to match. But it makes removing the pattern from the mold easier.
Attachments
Mold_D.jpg
Last edited by 4catmom on Fri Mar 30, 2007 10:16 pm, edited 1 time in total.

Harold_V
Posts: 17692
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Post by Harold_V » Fri Mar 30, 2007 11:05 pm

Dan,

Let me be the first to compliment you on your nice work, particularly with such humble equipment. I'm particularly fond of the idea of using an electric leaf blower for your air supply. That would likely be a decent source of air for a gas (natural or propane) furnace as well. I've always used old upright vacuum motors, but they're not exactly recommended for the job, due in part to the prolonged running time. I had one quit on me in the middle of a heat, but it was at a point where it wasn't troublesome, just annoying.

Can you talk a little about your experience with melting iron? I've gone a long ways out of my way to insure I can do that without problems when I finally get my shop up and running, yet you appear to have handled it with ease. Are you getting iron that's machineable, or do you have trouble with the carbon content? I'd also be interested in hearing about the crucible you use.

Very impressive, Dan..

Harold

4catmom

Post by 4catmom » Sat Mar 31, 2007 9:32 am

Harold, thanks for your kind words. I'll try to answer these questions in order.

I've said before that my iron technique is a work in progress, and that's still true. I'm attaching a couple of pictures of iron castings I've made before. I used to use petroleum coke when I lived in Louisiana, but don't have access to that fuel anymore so I'm using charcoal now. I don't think there is much difference in the temperature achieved, however; the charcoal definitely burns up faster!

The first picture is not really a cast part, but an iron "muffin" which I sawed in half. Although there is some porosity in the middle, it seems to machine pretty well. I was just messing around experimenting with my air preheater (see next post) and poured the iron into an old muffin tin when I was done.

The second picture is of an axlebox. This was a test casting, and I borrowed a pattern for the test. I'm not building that locomotive, so only poured one casting. As you can see, the outside surface is very rough. This is because of the lousy sand I was using, much too coarse. OK for manhole covers, but not for loco parts. By contrast, the inside surface (from the core) is pretty good.

One benefit (and liability at the same time) of using a crucible for iron, is that the crucible supplies some carbon to the melt, albeit by sacrificing some wall thickness. I've coated a clay graphite crucible on the inside with refractory to try to keep that from happening. My plan is to add some charcoal dust to the melt to add a little carbon. We'll see what happens. I also have some silicon additive to add to the melt.
Attachments
Axlebox.jpg
Ingot.jpg
Last edited by 4catmom on Sat Mar 31, 2007 12:01 pm, edited 2 times in total.

4catmom

Post by 4catmom » Sat Mar 31, 2007 9:46 am

The other problem with iron is getting to a high enough temperature. Although iron melts a little above 2000 degrees, it really needs to be poured above 2500, and seems like those last few hundred degrees are the hardest to achieve.

The biggest problem from my experience is getting enough blast. You don't need all that much blast for aluminum, more for brass/bronze, and a WHOLE LOT for iron! With that much blast, the fuel burns at furious rate.

I know that large blast furnaces use an air preheater, so I've been experimenting with that idea too. The concept is to recover some of the heat from the exhaust of the furnace and preheat the air going in. See pictures below. The way it works is, the air from the blower comes into the top of the preheater through the tube at the left, then flows back and forth through ten rows of tubes directly exposed to the furnace exhaust, and exits the tube at the right. This is built from 1/8 steel plate, automotive exhaust pipe, and steel conduit or copper tubing.

I've only used this one time, and it seemed to work really well up to a point. That point was when I melted the copper tubes out of the bottom few rows! I've replace those rows with steel conduit and plan to try again. But first I need to arrange a better method of attaching the preheater to the furnace, and I'm working on that now. The new attachment will allow me to regulate the amount of furnace gas going into the preheater, so hopefully I won't melt it again!
Attachments
Preheater2.jpg

Too_Many_Tools
Posts: 27
Joined: Mon Jul 31, 2006 3:25 pm

Post by Too_Many_Tools » Sat Mar 31, 2007 11:18 am

I can't see the photos that are being posted...why?

Is there some icon that you have to click on?

Thanks

TMT

4catmom

Post by 4catmom » Sat Mar 31, 2007 11:26 am

TMT,
Assuming that you are logged in, there may be a firewall setting on your computer that needs to be fixed. Search for "firewall" as I had a similar problem. Or, turn your firewall off temporarily to see if this helps.

(On edit) Duhh, I guess you'd have to be logged in to post a reply! :oops:

Too_Many_Tools
Posts: 27
Joined: Mon Jul 31, 2006 3:25 pm

Post by Too_Many_Tools » Thu Apr 05, 2007 8:44 pm

I figured out why I couldn't see the pictures.

I am on a 24K dialup and the text would come up so one could read it.

IF YOU WAIT a number of minutes, the photos appear.

I suspect the more photos or the larger they are, the longer you have to wait.

I hope knowing this helps anyone else who might be having problems.

TMT

Harold_V
Posts: 17692
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Post by Harold_V » Thu Apr 05, 2007 8:57 pm

I routinely hook up @ 26,400 bps-----so I, too, have to wait for pictures. Folks with a high speed connection appear to forget what it's like to have a dialup, so they often post unnecessarily large files.

That's an ongoing problem that I fought on a daily basis until Marty changed the software so a large thumbnail was displayed instead of a full sized picture. We now have an option of downloading the larger file, or not. Still, when large files are posted, those of us with a slow connection suffer to some degree.

Given an option, I'd limit file size to 75 kb, max. I've resized pictures such that they will display without spreading text, and are still very acceptable quality-wise when the file size is reduced to as low as 30 kb.

Harold

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JohnHudak
Posts: 1060
Joined: Sat Jan 04, 2003 2:18 pm
Location: Ohio

Post by JohnHudak » Sat Apr 07, 2007 11:30 am

Hey Dan, This might be a dumb idea, as I don't really know how much forced air is needed for your preheater, but would one of those hand held hair drier/blowers work? I know that when the wife uses hers, it puts out a blast of hot air!!! I'm thinking that would be your forced air and your preheater all in one. Also, some of them have adjustable heat and speeds....they're cheap too..
John

4catmom

Post by 4catmom » Tue Apr 10, 2007 11:50 am

John, I don't think the hair dryer would put out enough heat or volume of air. I don't have a good way of measuring the degrees of preheat from the heat exchanger, but I'm guessing it is in the 600+ F range. It turns the pipe a straw/brown color.

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