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Aluminum furnace crucible

08-01-2009, 04:04 PM
I made a new crucible for my aluminum furnace today. It was a fun project involving my CNC plasma cutter (Longevity ForceCut 80 powered) and my Longevity WeldPro LS 160P.
I first cut the circular base (made four of them) with my CNC plasma cutter.
Then welded the base to a 4"ID well pipe 7" long and gave it the water test, no leaks. I welded two lugs on the circumference for hinge points and a nut on the lower back to put a hook in for pouring. I heated the rim and hammered out a lip for pouring.
What is not pictured is the new device for hooking the pot and grabbing the nut for pouring. That is just two hooks on a handle that go over the lugs to pull the crucible from the furnace and is used as a pivit point for pouring.


08-01-2009, 04:05 PM
More photos

08-01-2009, 04:18 PM
Nice Job Gaget. When do you plan to do your first pour?

08-01-2009, 04:26 PM
I've been pouring for well over 15 years Keith, I'm just upgrading some of the equipment.


08-01-2009, 04:42 PM
I ment with the new crucible...

08-01-2009, 05:53 PM
Nice ideas on the crucible. The one I made looks very similar, although only about 5 inches tall, 4" OD pipe (Schedule 40?) though. The metals place I buy a lot of my material from had pre-cut circles that I used for the base, 1/2" thick. I too welded two pieces of 1/2" steel rod for the lifting ears, but wasn't sure what to do for the tipping lug. The large nut looks like a good solution.

I also like the pouring lip, I may try that. I did a pass on the inside of the crucible to eliminate the possibility of melted metal creeping in between the pipe and base and later causing problems. I read somewhere that it can be a problem as the metal expands and contracts. It wasn't too bad welding inside since the crucible was shorter. I just used a couple of new rods (longer) and later used the short stubs for other projects. After having used my old AC buzz box welder for years, the Longevity was so much smoother to use.

Although I haven't tried it yet, I'm hoping that the crucible isn't too thick for my tiny furnace (charcoal fired), although it should retain good heat as I transfer from the furnace to the pour.

HerbD 8-)

08-01-2009, 06:31 PM
With a half inch base I'll bet it will hold the heat very nicely.
I only welded the outside of my original pot and have used it for many years without trouble. I would think the uneven bead inside may lock the aluminum as it cools for any remaining metal in the pot but that probably would only be a thin film.

---------- Post added at 08:31 PM ---------- Previous post was at 08:18 PM ----------

I ment with the new crucible...

Sorry, I musunderstood. It will probably be next weekend before a pour, I'm going to look at a boat tomorrow. That and a 15 mile long run will probably take up the entire day.

08-02-2009, 12:06 PM
Great looking job, When I was in High School we had a small furnace for melting Aluminum. It was fun to mess with and make stuff. That was a long time ago though.

08-04-2009, 03:38 PM
Nice weld. I wish mine looked good enough to post close ups like that.