Introduction: Build a Forge: the Ceramic Tile Layer Cake
Essentially a forge is a place to stick cold metal to make it tremendously hot. A coke or coal forge is a bed of embers with air blowing through it as needed. It's a cozy place for your billet to hide while waiting to be smashed against an anvil.
A propane forge is very different. Instead of a bed it is a tunnel with a burner blowing down on the metal. When I started designing a forge I didn't know that both ends of a gas forge are often open so that a long workpiece can be passed through and heated along its length.
This forge design is meant to be done dirt cheap, easy as pie (cake!) and with commonly available materials. Everything here comes right off the shelf of one hardware store.
Watch my video and read these easy instructions to make your own portable DDC Forge
-A cheap steel cake pan or lasagne-type pan, as big as you can find
-10"x14" ceramic wall tiles (15 or 16)
-3"x6" tiles (10)
-One bucket outdoor firebrick mortar
-Tile hole saw to fit the burner nozzle
-The burner depicted in my post:
-Hardware cloth or light gauge steel mesh (optional (but not really optional, it turns out))
Step 1: The Space Shuttle Is Still an Inspiration. Forge Assembly
Not everyone knows this but the belly of the Space Shuttles were covered in tile. The tiles provided insulation against the extreme heat of high-speed reentry. It is thought that damaged tiles caused the Columbia to break up, tragically killing all the brave crew on board.
The stakes are not as high on this forge. But the heats are comparable where the tile is concerned.
You may need to tweak the sizes of tile depending on the size of the cake pan you find. Do a dry assembly of the base and sides to see what might need adjustment. This will make things easier when the cement is in play.
Lay a bed of mortar and perlite mixed 1:3 by volume. The perlite is very light and fragile but down at the base it will be protected by the steel pan.
Lay a bed of layered large tiles centered at the rear of the pan. Coat each layer with straight mortar so they stick together. This base is best if it can come up to the level of the pan rim.
Pack the left and right sides with the 1:3 mixture. Taper this to the angle of the side tiles.
Stack the rest of the large tiles on the sides, overlapping their top edges in an alternating pattern. Add mortar to the back of each tile to get them sticky.
(Major design correction note: After heating this forge the first time I discovered that the expansion of the tiles leads to a cracked top seam. I should have added steel lath or light hardware cloth between the layers of tile. When I build this again I will cut pieces of some mesh and a lay them over the center joint. This should prevent separation of the top seam and reinforce the side tiles in general.)
Fill up the remaining space in the pan with the smaller tiles and more mortar. Pack any major gaps with the 1:3 mix, then grout and coat all the joints with more mortar. Wipe everything down with a damp cloth for a pleasant, finished surface.
Step 2: Adding the Burner
Installing the burner is easier than falling off a lowboy and breaking your hardhat (true story) but you have to wait a couple days for the mortar to cure.
So why not go putter around your local hardware store while you wait? Say 'hi' to AJ and Yvonne from me if they're working. You'll need a tile hole saw or two. I bought one the size of the burner nozzle OD (1 3/4") and one the size of the ID (7/8") . Don't hesitate to buy one at least; whether you're cutting a drain hole for a pot, an extra faucet hole, a drain hole in a cool bowl-soon-to-be-sink or an opening for a shower stem, a ceramic tile hole saw is an indispensable tool to have around. And it really chooches through this tile.
Mark center of one interior wall and translate that to the outside. I did this with a speed square and a pencil. If I cut the hole at the center of the outside it would come out too high inside. Here's the long form video.
Skip to 10:16 to see how to easily lay out the right spot for proper burner placement.
Cut the burner OD hole at this mark until the center drill bit comes through the inside. Remove the material. Now cut the rest of the way through with the smaller hole saw. This smaller hole supports the nozzle and protects it from melting like a snow cone in Phoenix.
Install the burner by sliding it into the hole. Your forge is done dirt cheap!
Thank you for reading,