Good day!
While I normally don't barge into an established online community and ask for help without first attempting to contribute to said community, I find myself lacking specific knowledge that I hope you seasoned pros can help with. So I hope you'll forgive me and I thank you for your time in advance! I'm attempting to build my first forge but I'm not sure exactly what materials, burner, and fuel I should be using.
Design and Considerations:
I want to build a small, safe, and hopefully somewhat efficient forge, to anneal mild steel sheet (low carbon) pieces. These would range from 10 gauge to 18 gauge. But this is where it gets interesting. The forge would be used in the backyard of my apartment/townhouse, which means proper coal forges and oxy-acetelyne torches w/ rosebud tips are out. You know...don't wanna scare the neighbors (or landlord). Most importantly, these pieces will be of various sizes and shapes so I can't stick the piece in the forge's chamber without making a huge forge. So the forge's mouth would need to be vertical and the pieces resting on top of the mouth, moving the piece around until it has been heated all over. And after built has to cost less than $100.
My uninformed idea:
My initial idea is stacking several soft fire bricks and carving a bowl shape into it. The carved out bowl shape would be maybe 8 inches in diameter and maybe 6 inches deep. The forge would rest in a metal support with legs to stabilize and contain it. The torch's flame inserts into a hole in the bottom, while the workpiece rests over the bowl-shaped mouth. A hard fire brick acts as a door, resting on top of the piece, sandwiching it.
Begin Newbie Questions:
- I'm thinking Propane or MAP gas for fuel. I don't have experience with either for metalwork: is MAP worth the extra money per bottle because it will heat faster or is propane sufficient? I just have to anneal to dull-red or cherry-red color.
- I'm looking at the Bernzomatic torches. Some are "pencil" tipped, some appear larger. Does the tip matter much in this use?
- Since the forge is facing skyward, can the torch's flame enter from the bottom? Are there safety considerations regarding where the torch is positioned?
- Because the piece is receiving heat from below, and is not sitting in a forge's chamber, can the chamber be shallow like I mentioned?
I really appreciate your time and any information you're able to give! I'm normally stubborn and go solo on my ideas but I'm plainly just lacking expertise here. And I'd rather not blow something up!
-Mike