Metal Casting Zone

No ... really I'm stuck! I cant get my center form out. I took some pics and here's how my day went.
I used a "stove pipe" that I bought from Lowes to be my center form.
Hers is a side view.


I modified the Gingery method a little. I had 2 circular pieces of plywood to sturdy the form.
Here's the top view.


Instead of using pieces of wood to "shim" the form in place I fastened it to the bottom of the bucket with screws and a piece of wood.
Here's what it looks like from the bottom.


I packed it with yo ole trusty Sand/Fire Clay/Perlite refractory...
It looked as such.


I've never done any refractory packing before so I packed it TIGHT! ... er a little too tight ... the walls began to buckle a little.
I thought "no prob, I'll just lighten up a little" ...

Well when I finished packing and removed the top brace of the form, this is what I saw as I went to remove the bottom brace.

HELP!

Any ideas on how to remove a round peg from a square hole?

So, we're looking down from the top and your stove pipe is basically crushed. You may have packed it a little hard. Or, that's really thin stove pipe.
I think I would try to pry apart the seam on the stove pipe and get it to collapse. Since it's a clay base lining you should be able to scrape it and shape it back to a cylinder shape and get the form out of the bottom. If you can't get it out, just go ahead and fire it up. It will burn out. You'll have to get the pipe out though. I did about the same on mine, it didn't buckle but I couldn't get the pipe to come out. I was using a refractory cement so it had set up like a rock. Finally got it out with no visible damage. The clay should be like a very stiff sand until you put the fire to it.

Good Luck!!

I can't collapse it, the bottom piece of wood in inside the tube. And yeah, it's both flimsy pipe and packed tight...and these don't mix well.

I think I'll use my dremel to cut through the pipe with a cutting disk. then I can remove it and work on packing the bottom with refractory. Here's a link to my photobucket album. These pics are a little bigger and give a better view of what's going on.

http://s589.photobucket.com/albums/ss333/firestix/?albumview=grid

You must be like the Governator or something.

I'm not sure, maybe OddDuck would know, since it is a clay based mix, as a last resort you may be able to knock it all out, smash it up , rewet it and start over. I know you can mix up your clay and keep it sealed up until your ready to use it. Some people advise doing this so it can soak better and be more plastic.

I see you have worked on the pipe seam, those don't come apart as easily as you think they would.

Jammer wrote:
I see you have worked on the pipe seam, those don't come apart as easily as you think they would.

Yeah ... but maybe that's a good thing. I mean, imagine it coming apart if I were using it for something crazy like ... uh ... I don't know ... an exhaust pipe for my wood heater!

Don't laugh ... ppl do crazy things with sheet metal rolled into a cylindrical form.

Poke a hole through the bottom of the bucket and smash the bottom former out with a small pipe or metal rod. After that former is out, just crush one side of the pipe. You can then smooth out the interior with a trowel or something, it doesn't have to be perfectly cylindrical, especially where you are using charcoal. You want a drain hole in any case for WHEN, not IF, your crucible springs a leak mid-melt. Barring that. and if you really want to save the inner form, just dig out the clay and start over. As long as it isn't fired, you can re-wet and use it. Might even be better second time around due to the inadvertent mulling you did by ramming it into place. Next time, don't seal the seam up, just overlap it and tape it. drill a hole in the top former and fill your form with dry sand, this will help weight it down and will give some resistance to buckling. Also, rework the bottom former a little and sand or cut off about 1/4" on the diameter, so it is a hair smaller at the bottom. This will seriously aid in removal, and will not affect performance in the least.You could also make a sleeve for the form with wax paper or plastic, so the clay doesn't even touch the form. Just slide the form out of the sleeve when you are done, and peel the sleeve off the clay. More than one way to skin this particular cat...

excellent advise odd duck and jammer i cant add anything more or less.

I'm not worried about salvaging this pipe, but in the future can I just use a Sewer pvc pipe from Lowes .... I figure that with the wax paper trick should work wonders.

Think it'll work?

As for removing the former, I think I'll follow the advice of a friend at church. He told me to get an 18" extension and use a paddle blade to cut the former enough to remove it.

yes anything like that should work. personally i would just burn it out.a bit of heat isnt going to affect the lining but if you decide to burn it out leave it for a few days.

Just get a chunk of sonotube. Pvc may give off some nasty fumes when it is burned out, and the somotube would be just as rugged, and probably cheaper. One sonotube for under ten bux would be enough to do three or four of that sized furnace.