In this Instructable I will be explaining how to convert that old barbecue grill sitting in your yard next to all that junk into a furnace capable of heating up steel to forge long items such as knives,daggers,and small swords. Before we begin I would like to say I am not responsible for any injury or damage caused by reading and/or following the instructions in this Instructable and working with hot items will always have associated risks. I would like to give credit to Tim Lively as I watched his movie called Knifemaking Unplugged and have based 1 of my refractory mixtures and the design of the forge off of what he uses. Great movie. I ordered it off of Amazon Unbox.
Step 1: Clean That Crap Up!
First we will want remove all the internal components such as the rack and burners. Strip it down to the bare grill body. Remove all knobs and such so that all you have is the metal grill. Remove and throw out the handle, if it is plastic. Now we will use a blowtorch to heat up the grease that has accumulated from you chowing down. We will heat up a section of the grill with the torch and scrape the the heated section with a metal scraper. Now we will heat it again and this time we will wipe it down with a paper tower. Once your satisfied that it is nice and clean proceed to spray it with oven cleaner, just to make sure. Let this sit for a while and then spray off with a hose. Let the grill dry.
Step 2: Constructing the Tuyere
Now we will construct the tuyere. The tuyere is a pipe that delivers an air blast from a blower to the fire that allows the charcoal to heat faster. We will need black iron pipe 1 1/2" diameter that is just a little longer than the length of your grill. We will also need a 1 foot section of 2" black iron, a 2 - 1 1/2 reducer coupling, and a 1 1/2 end cap. Now we will put the 2 inch pipe into the reducer and screw it on. Now we will screw in our 1 1/2 inch pipe into the reduce. Now we losely screw the cap on. The cap is to allow for easy clean out. Now we drill holes in the pipe every inch about 1/4 inch or a little less. Remember the more holes you have, the more oxygen to fuel the fire but, also the bigger a blower you need.
Step 3: Adding the Tuyere
Now that the grill is dry, we will use a circular hole saw and cut as close to the bottom off the grill n the center on both sides. Make sure the hole is just large enough to accomodate the tuyere. Slide the tuyere in and screw the end cap on.
Step 4: Adding Refractory
Of course, to keep the forge body cool enough so it is not damaged, we need a layer in between the fire and the grill. I will use Mt Savage refractory cement, although you may use 1 of the following recipies, a 1 part furnace cement and 4 part perlite or 50/50 of sand and clay. We will want to fill the forge right to the tuyere and have a 70 degree angle upwards to provide a trough to hold our fuel and blade. Let dry.
Step 5: Get Fancy
If you haven't noticed, I have been fancy with my grill and added a plywood shelf underneath to hold my charcoal and tools and I have added a small plywood table where 1 of the plastic ones used to be. I will be adding sheetmetal to the plywood surface to keep it cool.
Step 6: LOAD AND FIRE!
Now we will load it with charcoal and light it up for use. We will begin by adding some newspaper at the bottom and then placing small dry wood kindling on top of it. Next we will top that with charcoal. Preferably homemade charcoal as it burns better, doesn't stick to your blade, and it has less flying debris. Light the news paper and wait for some of it to catch fire and then turn on a blower device connected to the 2 inch pipe. I personally use a shopvac. Enjoy. Be careful. If you now have a forge but no idea how to make anything, stop by livelyknives.com or amazon.com and buy Knifemaking Unplugged. And im sorry but i have no photo as all this was taken while i was waiting for the cement to cure.