A first project to break in a new furnace

Before you laugh at the Halloween themed furnace, I could not help it, the container was the perfect size and had for free. I thought the paint would burn off after the the third time the furnace has been fired, but it seems my refractory is that good, despite the sloppy novice looking concrete work


So recently, I built the furnace I was talking about that would be much better than the one in a previous post, and here it is, In the above picture. Unfortunately, I didn't get any pics of the building process. This new toy of mine has a lining of 3000 deg F rated castable refractory, 7 3/4 diameter burn chamber, and is souped up with a Ron Reil propane burner. The first firing consisted of charcoal and a bit of forced air to burn out the center form- a core on which paper would be wound onto at the mill. The second firing was a test of the propane burner I built during which I melted a couple handfuls of brass keys. It was a roaring success.

This post details the third firing, for a more meaningful project. I have a good friend who has been battling throat cancer for a while now, so I decided to make him a little something because he is interested in what I do when I melt metal.

Last night, I carved the pattern for the piece to be cast from lost foam. I have not yet built a hot wire foam cutter, so a big bread knife was used to cut the shape. After that, a small screwdriver heated with my propane torch made an engraving tool, followed by sanding with some emery cloth. As you can see in this pic, I covered part of it in drywall compound. Why not the whole thing? Because this project is also a learning experiment for me.

The next day, the drywall compound was reasonably dry, so I fired up the furnace loaded with aluminum drink can ingots I made in the past.

Once the metal melted, I skimmed off the dross. There wasn't a lot of it either. The pour went well. Here is the raw casting:

And cleaned up a little:

It is just a little decoration with my friend's initials and a cancer ribbon. Despite the casting coming out perfectly as it should, My head slumped in disappointment, And I learned I have a great deal to learn about workmanship. This is my third lost foam casting, but the first on something I want to do, rather than screwing around, and It is back to the drawing board.

First (Controlled) Aluminum melt

This hole saw tool is bullocks

After spending at least a year reading web pages and watching videos on the internet to learn how to properly build a foundry, I had finally decided to stop screwing around and finally just melt something. I had been studying and overthinking every little aspect of home foundry work up to this point. I was so determined to do everything perfect from the start, that a year had passed before I actually melted some scrap. Needless to say, my mind had become so overwhelmed with information, that the planned perfection was thrown straight out the window by this time. 

Here is my first setup:

Lets start with the furnace cobbled together vessel that generates heat. For this, I used an empty freon can. My father is a HVAC serviceman, and happens to have an endless supply of these in his junk pile. Since it was free, it was a donor specimen by default. I began to turn this into a furnace the same way any other would, puncture it and cut it open. This was all the farther I had gotten a year ago. 

Skip ahead to November, 2015 when I performed the first melt. After a long 12 hour shift at the paper mill, I came home on a Sunday morning, and got straight to work. 

Here are my modifications to turn a Freon tank into a furnace:

1. The lid was re attached with a hinge, and a 3 inch hole was made in the center

2. A hole was made to accommodate a 2" pipe nipple about 2 inches from the bottom. Said pipe nipple was held in place with sheet metal clippings and hose clamps
3. Three holes were drilled around the perimeter and bolts were fastened into them with washers and nuts to accommodate the shelf my crucible sits on. this was made out of a drip tray from a stove. all I did was cut some excess metal off the diameter of the drip tray. Three flat spots were hammered into the tray that corresponded with the location of the bolts I also drilled holes all over it to allow air to the charcoal briquettes that fueled it.

As a crucible, I cut the top off of a 1lb Coleman propane bottle. Before cutting, I removed the relief valve with two small screwdrivers. Its the same principle as a valve inside the stem on a tire, just larger. You could also find a circular metal bar of a diameter that fits the hole where the valve resides and grind a slit in it, but that is a lot of screwing around. I would advise against doing this anyway, as this crucible was only good for one melt.

Here is a shot with the furnace, if you want to call it that, fired up, and I am pushing pop cans into the crucible. To start, I packed some Kingsford charcoal briquettes around the crucible and lit them as you would a grill. Once they were burning, I connected the vacuum cleaner, set to blow air, up to the pipe nipple on the bottom with a rubber coupling. I had a roaring inferno going in it and the outside of the freon can was glowing red at one point. I found that I had too much air going in. To combat this problem, I disconnected it and set it about 3 or 4 inches from the pipe, as you can see in the picture, and this worked much better. 

 Once the crucible was glowing red, I started putting pop cans in, and once I started to get a pool of aluminum, I began pushing them under the surface of the pool with a steel rod. Safety sissies will tell you that you can't melt pop cans with moisture in them. Safety sissies tell that if you do, boiling hot water or aluminum or what ever other liquid name they can pull out of their ass will splatter all over your hands and face and eyes. It's all bullocks. And I defiantly didn't lose my eye sight, as I can clearly see to type this post. I can already hear some one whining, "But wait, you set them in the pool open end up so the liquid could boil out before being submerged! :'0" Well, no, I took the liberty of plunging some straight to the bottom of the melt open end first, and still, not blind of burned. All that happened was the aluminum bubbled a little in the crucible. No metal left the crucible, no violent explosions, none of that. Just a fart in the bath tub. It just goes to show, that when you work with things like this, all you have to do is use common sense, and of course, you can not be scared when your doing things like this. If you are, I suggest you take up, Popsicle stick art, ant farming, video games, or some other dangerless hobby that you can find on Pinterest, and leave this kind of thing to better qualified people. (To hear more rants about this kind of thing, check out this guy. If you are interested in home metal casting, his videos could be of some use to you.)

After I had melted the bag of cans, I poured the metal into this mini muffin tin. Once cooled and time to remove the ingots from the tin, I found myself scratching my head, and saying "Shit." when they wouldn't  fall out. Turns out the cheap ass muffin tin I bought from Family Dollar was Coated in tin or something, and it caused the ingots to solder themselves to it. I had to mutilate the hell out of the pan to free them, ultimately giving up and remelting them at a later date and fishing out the parts of the steel once the alum had melted. 

 Here is a shot of the crucible I built for my second melt. I did not have a choice, as I found a weak spot in my first one when wrapping on it with the corner of a chisel. This one is a 5 inch chunk of 4" diameter steel pipe with a piece of plate steel welded on, and it works great. Especially for melting metal that creates excessive dross, as you can really bang it on the concrete and not have to worry about breaking it.

 So there you have it, Simple and easy aluminum melting. This crude method is good if you are as indecisive as to how you want to build a furnace as I am. This pile was contracted up in about an hour one morning when I got sick of doing research and just wanting to melt some damn metal. Goes to show you can too. 

First attempt at green sand

For about a year now, I have had an itching interest in doing my own metal castings. I particularly want to make belt buckles, and maybe some machine parts and what have you. From the get go, my mind has been flooded with a LOT of information, and a lot more bullocks. Thankfully, there are a few people who know what they are doing so I am starting to figure this out. So, as my first posting, I will write about how I made green sand what ever the hell this is, so far. There will be updates as it happens. 

Here we have some cat litter from wally world, which said Bentonite clay in the ingredients and some play sand in a 50 pound bag from Home Depot. To start, I measure out 5 pounds of cat litter, and ran it through that hamburger grinder clamped to my wire spool work bench. Ya know how some times you go to rummage sales and buy some trinkety little thing for no apparent reason what-so-ever, and your spouse looks at you like your a moron for wasting the money? This grinder was one of those, after loads of haggling and minutes of listening to some crap from the dude conducting the yard sale wine about how it was his mothers, "blah blah blah, its a family thing, very sentimental, yet I am going to sell it in my yard sale, blah blah blah." Any way, cat litter goes into grinder...

...And then gets sifted through this window screen. What ever did not fall through went back through the grinder. This was about 2 hours worth of work its self. At one point the grinder came unclamped from my work bench. After I finished this batch, I weighed what I had and then weighed an amount of cat litter to make up for what spilled. I have found that the litter ground up into powder quicker with less passes through when the hopper was kept full at all times, making it harder to crank as the trade off. When it came unclamped, I had the pitcher full of litter resting on the hopper to keep it full, and this spilled too.

Intermission

I had worked up quite an appetite at this point...

... So I stopped and fried up some deer meat. These in particular are rump steaks. I started by adding a sizable chunk of butter to that pan and letting it melt. Once this was achieved, I added the steaks and cooked them fairly quick on both sides to a rare to medium rare. I then proceeded to eat them at the kitchen counter since I didn't want to tease my dog who was in his crate in the other room.

I then brought him outside and left him chew on that bone for a few minutes. He is a beagle and presumably blue heeler mix. His favorite toy is that shoe behind him

Back to work

 Now with what I thought was the hard work finished, It was time to mix the sand. I poured the whole bag of sand on top of the powder in that pink tub. Big mistake. I should have mixed the powder and sand in smaller batches because it was harder than hell to mix thoroughly. That being said, I mixed up as well as I could. I am not too concerned though, because as you ram up molds, that will help somewhat to distribute things out better as it is used, I hope.

I scooped a small amount of the mixture onto this bin cover and sprayed it with that water bottle...

...Then mounded it up like so. The next step was to beat it with that rubber hammer. Now I have read one of C.W. Ammen's books, in which he talks about conditioning foundry sand. He talks about shoveling it into windrows and giving it a sharp blow with the shovel to smash it down. He also talks about tamping it with the rubber peen on the handle. After reading that, I tried to apply the same principle here on a smaller scale.

I repeated the above process as many times as necessary until I got something that held together and got something resembling somewhat of a clean break... kind of.

Once this was achieved, I threw the batch into the container with no regard to moisture at this phase.

Eventually, I noticed the hours slipping away, so I started mixing the water into the whole container full of sand that needed to be worked. Like mixing the powder, I probably should not have done it this way, because I was only about a third of the way through the mixture at this point. But having no regard for moisture content at this phase, I pulled the trigger on it. Once all the sand was moist, I scooped it out as before and beat it with the hammer until there was a manageable amount in the metal container. At that point I used a plank in place of the hammer and performed the squeeze test as I scooped it out.

Once all 55 pounds of the mixture had been worked, I covered it up with the bag the sand came in and set those ingots I have from another set of catastrophes to seal it. Referring again to C.W.'s book, he says this will allow it to peculate and the moisture will distribute. I shall let it sit for a period of time and check up on it later.

There are two reliable internet sources of information that I have been going by, and if you have not checked them out, you should, they are very informative.

1. Lionel Oliver II's page at backyardmetalcasting.com 
He has a lot of great information on his happenings, and was the first page I saw pertaining to metal casting at home when I started doing research.

2. Myfordboy's page at myfordboy.blogspot.com
Even more and better information here. And not only metal casting, but he thoroughly explains how things are done from furnace building, to casting, to cores, fuel burners, to machining, and MUCH more. I would highly recommend checking this out, if your not already familiar.  

-More shenanigans to come soon-