Metal Casting Zone

I have made 2 crucbles useing a commercial refractory with heating wire for reinforcement. I played around with useing clay to make one but have not tried to fire/melt in one yet. I know some have done it and have used them to melt iron in.

For someone wanting to try it, here is a PDF on about how it is done.
Two ways are talked about, slip casting and ramming.

www.copperstarways.com/Downloads/MakingCrucibles.pdf

great job. Thanks for the input

How long would a crucible made from a fire extinguisher bottle last? I have several around the shop that could be sacreficed for the cause. Also have an old CO2 bottle from a beer keg tapping setup. Never found a place to get it refilled! That would be on the same lines as a propane tank with out the hassle of trying to make the tank safe to cut by torch or cutoff wheel.

I think you should carefully cut it after the pressure is out and measure the thickness and guess the strength.

You probably will not know until you try, then let us know. i have about 15 fire extinguishers myself.

good thinking,

i haven't tried it but it sounds good.

i like non-flammable bottles to cut.

the extinguishers may be perfect.

be safe but give it a try...

irontwig

Ya might know. Found a dead fire extinguisher in the shop. Wrote down the Manufacturer, model, class, etc, and looked it up. BC Class dry siliconated sodium bicarbonate. Cool, safe stuff. Took it outside and pulled the trigger, no pressure left. Good again. Proceded to remove valve and dump powder into a plastic coffee can. Headed to the bench to cut it up. Valve and handle were aluminum, AAAuurgh!!, Melt! Thought, this canister feels kinda light, checked with a hd magnet, no attraction. Scraped with a carpet knife, AAAuurgh!! Aluminum! The fire extinguisher canister was aluminum!
Well, that's Chuck's Law in a nutshell! Nothing is what it should be unless you haven't thought of a use for it... Well, other than the painfully obvious that I can't tell red painted aluminum canisters from red painted steel canisters... Oh,by the way, the other, still good fire extinguisher is ina steel canister... Magnet tested. Fire anyone?
Nuf rambling. Guess I'll have to let someone else try making a crucible from a fire extinguisher canister, my gut tells me not to waste the good one, I'll probably need it

AAAuurgh!!AAAuurgh!! Melt!

Thanks for the update.

I found another fire extinguisher hidden away that was probably 30 years old or more. Pressure gage said it was still good, but when I went outside to test it it ran out of pressure long before it would have done much good.
After the last fooh-pah, I checked it with a magnet and it was indeed steel. Looked like it was assembled from 2 pieces, perfect ring around the middle to use as a sawing guide. As before, I unscrewed the valve after discharge and pored the remaining powder into the coffee can used before. Now have a 1/2 of a 3 lb can of powder, will it make good parting dust? We'll see.
I secured the empty tank/cannister in my vise and hacksawed along the aforementioned line. Here's what I got: 3" x 5" can wall thickness a little less than exhaust pipe. That probably won't last too long but should do a few melts. I'll test today... Had to put the pic on my geocities website, couldn't get it to attach here...
www.geocities.com/chucketn/casting/Fire_extinguisher_crucible.JPG

Let us know how it goes. I am going to attach your picture for you.

Just came in from melting a pot in the fire extinguisher flask. Posted 2 pictures at

www.geocities.com/chucketn/casting/

. Layout shows furnace,open top sand mold was in the bucket, the plastic bottle I used as a form in the sand bucket, and the resulting ingot approx 2 1/2" x 4". I actually had more melted than I thought.
This is what I was getting at. Baby steps I know, but I'm a slow learner. I now realixe the ingot is too big for my intended purpose, so I'll remelt it into another form.
This was mainly an exercise to show it can be done simply, safely, and on the cheap.
I also learned how much casting sand is 'burnt' by casting. The burnt sand was about an inch thick when I dug the ingot out of the bucket.
Next melt will be for something usefull!