Introduction: Gasifier Forge
This is a light weight portable forge used for melting down aluminum cans as part of a scout project. The required materials are as follows:
metal 5 gallon bucket, outer body of the project
8 inch diameter stove pipe 1 foot in length, inner belly of the beast
1/2 inch diameter pipe 2 inches long, used as a lighting tube
12 inch by 12 inch piece of expanded steel, used as a grate
several short screws to hold it together
12 inch by 12 inch grate from an old grill
metal wash basin with the top about the same size as the 5 gallon bucket, used as a blower base
4 inch diameter sheet metal dryer vent tube about 1 foot long, used to keep the fan away from the heat
80mm - 120mm Computer Case Fan and power supply (12V +/-)
8 inch to 6 inch chimney reducer, used as a reducing top
Drill with bits to fit your screws, 1/2 inch pipe, and making air holes, hole saw can work.
pipe or bar used to make the air flow nicely within the system
screw driver (short) for screws
tin snips (straight will work, left or right are nice, opposite of your dominant hand)
Marker or pencil for planning out and marking metal
scratch all (optional, but useful for marking and starting drilling points)
Step 1: The Body of the Project
Using the 5 gallon bucket and the 8 inch pipe the body of the gasifier is made.
important concepts are that the gas needs directed back into the 8 inch tube, thus holes around one end of the tube, and those holes are attached into the bucket, near the bottom of the bucket, will be the top of the body.
Turn the bucket upside down and mark the opening needed for the 8 inch pipe, this may already be one of the rings on the bottom of the bucket.
Mark on the expanded steel where the pipe fills, as the sheet will need cut so that it can sit inside the pipe with some flaps to hold it in place with the screws. This cut piece will need to be 1/3 to 1/2 way up the 8 inch tube, and would be worth drilling the holes fore before the tube is in the bucket.
Mark on the top of the bucket where you want your air intake holes to be (the side with the handle)
You will also want to mark the bucket and 8 inch tube for the placement of the 1/2 inch pipe, this will need to go through the 5 gallon bucket and the 8 inch tube, preferably at a horizontal location just below the tabs on the expanded sheet metal inside the 8 inch tube.
Step 2: Measure Twice, Cut Once
Once you have all of your marking made, and have done a test run that it will all fit together, it is time to cut it out.
Start with the 8 inch tube, placing your many air holes around the one end, this willl be the top.
Cut the expanded sheet metal, I used bolt cutters, but be careful, so that you have the size to fit in the tube, and bend down your tabs for support.
drill the pilot holes in the 8 inch tube for the grate, and screw it in place, a short screw driver will be nice for the close quarters.
Double check that it supports some weight, adding more screws if needed, and then double check that your 1/2 inch pipe is still below the grate and not running into any of the tabs.
drill the hole barely large enough for the thread of the 1/2 inch pipe.
Onto the 5 gallon bucket...
The bottom of the bucket is going to need most of that area for the 8 inch pipe removed, I recommend about a 6 inch circle centered inside the 8 inch circle, it may be the next ring towards the center of the bottom of your bucket.
The remaining inch can be cut like a pie or pizza, using the difference as tabs to hold the 8 inch tube in place, you may want to have a couple pointing up to center the 8 inch to 6 inch reducer over the hole. ( this will make sharp pointy pieces on the top of your bucket, and will not make it sit correctly when traveling)
Double check that the 1/2 inch pipe lines up with the 5 gallon bucket, and drill the hole just large enough for the thread into the 5 gallon bucket.
With the 8 inch tube in the bucket, screw the 1/2 inch pipe into both pieces, may need to have someone with skinny arms help, so that it is secure.
Drill pilot holes for the 8 inch tube to attach to the tabs in the bottom of the bucket, and screw them together.
The tube should be inside the bucket completely, and fit solidly, the gasifier body is done.
Step 3: Bottoms-up
Remove the plastic flappy pieces from the dryer vent, you want the air to go in the out.
attach the fan to the plastic frame, goop or screws work well for this, the goop holds without pointy screws to snag things on.
print out a 4 inch circle, or draw one on a piece of paper, and tape it to the wash tub, this will work as a template for the hole you need to make on a very odd and curved surface. Place the tube and fan combo up against it to make sure they sit nicely.
Cut out the hole for your fan combo, and make sure it will slide into the hole. Tight is not needed, but it should fit in nicely, and not wobble like a child learning to walk.
Confirm that the stove great sits on top of the wash tub, and will support a bag of charcoal being placed on it.
Step 4: Prepare for Ignition
In a safe place to watch it burn, put the wash basin on the ground, attach the fan combo, and put the grill grate on top.
place the 5 gallon bucket on top of the grill grate, so that the handle is down, and out of the way( if it still has a plastic handle, it will eventually burn off.)
dump small twigs, some kindling, charcoal, paper, what ever you are burning into the 8 inch opening on top. don't pull a cave man and stuff it solid as a rock, but fill that thing up.
put the 8 to 6 reducer on top over the hole, and find a torch or long matches or lighter.
Using the 1/2 inch hole insert your lighting tool up under the fuel of your forge, and let it get going with some heat. if your don't used a bunch of kindling and fire starter, you will want to use a torch that can be left in the pipe for a bit.
Once you finally get it up to temperature, and have some flames coming out the top, power up the fan, and turn off the torch.
With the added air you will be lucky if there is not flames coming 6 feet up from the ground, and it will be very hot, I have had temperatures reaching 1400 F / 760 C
Step 5: Final Thoughts
We use this to melt aluminum cans and cast them into other scout objects: a pocket hatchet, mess kit, challenge coins, metal muffins, sling-shot ammunition
The fire, body, base, fan tube, handles, top, and area all around the forge is very hot, like McDonalds Coffee but mixed with Lava! Don't burn yourself and think you are special, we all do it, and learn the hard way. It isn't my fault, I am not liable, and you need to learn the hard way like every one else.
Competent Adult Supervision is Required
Have fun, and let it cool for hours after you are done, do not place this in your car, truck, van, or SUV right after you are done.
I use fire place tongues to help move things around, along with welding gloves and pliers. The flames will take off your arm hairs, eyebrows, bangs, Justin Bieber hair cut, back hair, leg hair, skin, knuckles, and silly clown shoes.
I wear leather boots when working with this, I might recommend that you don't go barefoot or wear sandles as the skin on your feet is very sensitive to burning hot liquid metal and red glowing iron.
I have done my best to keep it simple, please don't be stupid.