Intro: Ultimate Guide to Making a Cheap But Effective Aluminium Forge.
There are many guides and many ideas I've collected and, being that I completed this (the first one... I made a completely new setup just for this instructible... you should feel special.) within two days and most importantly... cheaply.
My cousin /assistant / camera man and I created this instructable so we could share our wonderful smelting smelting experience and win the hearts and minds of the instructable community.
This instructible includes fire and molten metal.
BE CAREFUL and USE SAFETY EQUIPMENT!
Also; If you mortally wound yourself while duplicating this instructible, please delete this from your history internet history before dieing. i don't want to be held liable.
BACK ON TOPIC!
We shall begin.
Step 1: Parts / Tools
In retrospect, the parts / tools list quite long but it should be things that are easily available.
The most expensive thing was the torch. I'm really cheap but it turned out to be a rewarding investment.
The other parts are as follows:
Quick Setting Quickrete (I got a 20 lb bucket for under 10 bucks)
Something to mix the Quickrete in
Something to stir the Quickrete with
Large Coffee Can (6 inch)
Small Coffee Can (4 inch)
Hack Saw (or any metal cutting tool)
Drill (or metal punch or improvised hole making tool)
An empty 14.1 oz propane tank (make sure it's competently empty)
Scrap steel bar like from a printer, about a foot long (you can buy 5/8 steel bar at lowes)
A sharpie (or any marking tool)
Short (about 2 or 3 inches) iron or steel tube that the torch head fits in. (optional)
A ball peen hammer (any hammer will suffice)
Some propane gas (i buy the ones for camping stoves because their $4.38 for a 2 pack of 16.4 oz tanks.)
An oven (optional)
A vice. ( kinda optional. you could find another way but i find the vice necessary)
A mini muffin tin (optional. you just need something to pour the aluminum into.)
Some cheap thin steel wire (1/8 diameter max. but strong enough to hold some weight)
Step 2: A Suitable Crucible
So I took the empty 14.1oz and put it in the vice.
We used my hack saw to cut just under the seam then de-burred the edges.
If you look at the bottom you should see 4 holes. Use a marker to draw a line up the side in line with a hole.
Use the ball peen hammer (or any hammer) and bang out where the line is. This will make a spout. (may take a little working to get it right but as long as it's there, pouring will be easier)
Now draw lines up the sides from the holes adjacent from the side with the spout.
About 1/4 inch from the top, mark the line, and drill at that mark on both sides.
I used a drill but anything number of things could be used.
Make sure your metal bar fits in the holes.
Put on a pair of leather work gloves.
Now mark the center of the bar.
Heat it up over the torch.
When the metal turns red, bend it in half to make an acute angle but not completely in half. (see picture)
Quench the metal in some water and heat up the ends one at a time. Bend them in so they face each other.
Quench the ends and re heat the center bend. Unbend it and rebend it so the ends that you bent in fit into the holes in your half of a propane tank.
Quench the center bend and ensure that your new handle moves freely in it's holes.
You are now the proud parent of a crucible.
Step 3: The Forge
This is kind of difficult but has few steps.
Cut a hole in the side of the big can about an inch from the bottom.
Make sure the pipe fits. (you could use a piece of rolled up paper or cardboard.)
Use a can opener on the bottom of the small coffee can and cut a mouse hole shaped hole in the lower side. (make sure the pipe fits)
Wrap the small can in cardboard. (this is to make it easily removable.) and cut out the mouse hole in the cardboard.
Mix the quickrete. We used 11 cups of quickrete and about 2.5 cups of water.
Pack the quickrete tightly in the bottom of the can and up to the bottom of the hole.
Place the pipe in the hole and the small can in the big can with the pipe in the mouse hole. Try to center the small can.
You want the pipe to go in diagonally. This will help create a spiral of flames. (see picture)
Fill up the sides with quickrete and pack tightly.
We let it set for a bit then put it in the oven and set it to 400.
After 30 minutes take it out and pull out the small can and the cardboard.
Put it back in the oven for 2 hours. This will help eliminate the moisture.
Use oven mitts and take it out of the oven. and bring it to our work area.
Lite the torch and stick it in the pipe.
I suggest wearing eye protection.
This first firing is just to eliminate moisture. You may see steam coming from the cement.
Let it fire for about half an hour then let it dry overnight.
We put the crucible in during the first fire to help burn off the paint.
Step 4: Melting Aluminium
This is pretty much the most dangerous part so have water near by and wear thick leather or welding gloves as well as safety glasses and make sure the area is well ventilated.
You're going to want to fire it up and put in your crucible.
I'd wait until the bottom of the crucible is red hot. (just a personal preference.)
Start out with small pieces of aluminum. (I had "pipes" from an old wind chime.) You could use cans but they tend to have a lot of slag. I'd wait until you have a nice quantity of aluminum before using cans.
You'll probably have a rough start so go slow. After you get a good quantity of aluminum it will be able to maintain a melting temperature and you can melt down large pieces in seconds. I have found an old knock off of a razor scooter in th back of my garage that has worn out it's usefulness. I found a new use for it's aluminum.
I have found covering the crucible with the top half of the empty propane tank helps keep the heat in and keeps things moving along nicely.
I had a troublesome piece of scooter that didn't want to release it's steel screw so I dunked it in the pool of molten madness and that half didn't come back. A mallet made short work of the obstructing piece of metal and allowed us to make a deposit in our crucible.
After you either fill up your crucible or run out of aluminum, you need to scrape off the slag. The slag will be floating on the top and will look a little different than the metal underneath.
We used a scrap piece of metal to scrape off the slag. We used the same scrap to make a hook to pick up the crucible and another piece to fit in the holes on the bottom of the crucible so you can easily pour it. You could use a small screw driver for this.
Make sure you have something to pour the aluminum into. I am just going to save them for later so I'm pouring them into one of those "mini muffin" tins just because they're small and fit in the crucible. You could just use an impression in wet sand or something. Muffin tins are faster. But don't expect to use them for muffins again.
Pour gently into the mold of your choice. IT IS HOT! WEAR PROTECTIVE EQUIPMENT!
Because I'm impatient, I wait until the aluminum in the tins are solid then throw them into a can of water. The water may boil violently after a short delay. It is a sight to behold but dangerous.
You now have aluminum ingots.
Step 5: Now What?
We now have a lot of ingots. You now can use the rest of your free time planning on how to get a hold of a harbor freight micro-mini-lathe for $250.
I figure we could cast some blanks that can be worked in a tiny lathe but that's for later.
We'll Make an instructible on casting aluminum when we get it down to a simple science.
We hope you enjoyed this instructible and happy smelting.