Hebel Forge Build

[DylanK]

Well I have wanted to start making knives for ages so I decided to make a simple gas forge. I was originally going to use a coal forge, but decided gas would be better as its cheaper and neighbour friendly. After lots of advice from Jindydiver (thanks mate), countless hours spent reading on the internet, and a bit of cash, I got started. My dad also helped as he had seen these venturi burners used in Hungary to make pigs skin all crispy.

I got the idea from a website where two hebel blocks where used. I only wanted to use one though. Dimensions are 600mm x 200mm x 200mm. I apologize for the large pictures but resizing them in photobucket didnt work.



I then cut it to length, and then in half. I used a normal saw for this but it does blunt it fairly quickly. I then cut and removed material from the middle of both halves. Cut a hole in the side for the burner to go through as well. I used one of those fish scalers that are saw toothed and round. Quite affective but took awhile.


This is how it looks when put together,



Thats basically it for the forge itself, now onto the burner. I was really nervous about building a burner as I didnt really have any idea about gas or how they work and didnt want to blow my house up. A few more hours on the internet and some good advice, and I was off to bunnings to buy some pipe. I know galvanized steel is not ment to be used, but I could not find anything else and I figured I would be outside anyways. This is what I started with


The galvanized pipe with reducer on the end to act as a flare, a jet from a barbeque, and some scrap steel that fit the jet nicely. The jet had 0.25 written on it which I assume is the size of the hole. I tried it and it didnt let enough gas through with the 20mm pipe. So I drilled it with the smallest bit I had which was around 1.3mm. This is how it looked put together. The scrap steel was welded to the pipe and the jet was just wired onto it. I didnt want to permanently fit it as I would still like to use the barbeque.


The end result was this



Inside the forge the flame is kinda of in a vortex which distributes the heat evenly. In about 5 mins it heated a file to non-magnetic. My burner is not the conventional venturi design, its more like a bunsen burner with air holes in front of the jet. I have seen this on another website and he seemed to get a very nice neutral flame. My flame is a bit rich I think, but perhaps someone could tell me?



At the end of the day it was cheap costing all up of about $25 and does what I would like it to. I dont have a regulator and it seems I dont need one. Hopefully my first knife will be started soon.

Dylan

[jindydiver]

You are doing great

If you are getting some yellow flame out the door of your forge you are running just fine. This tells you the oxygen is being burned up and it will mean less scale (and decarburised steel) on your knives to clean off later.

You need a couple of fire bricks to put at each end to seal it up a bit.

[GrahameA]

Morning Dylan

Another use for Hebel. Excellent little post.

Thank you.

[jape]

Good to see, working well! Just watch that type of hose clamp, I have found they bite into the hose and can cause failure in some plastics, seen a leak start from one so don't blow yourself up!

[DylanK]

Thanks fellas. Yeah hopefully I wont kill myself. I plan on buying a longer hose and have it properly set up so it should be alright.

I tried sealing it up a bit at the back but then I dont get a vortex in the forge and the burner doesnt burn as well. I still think it may burn to rich, hence not a pure blue flame.

In the process of making my first knife, will see how it turns out.

Dylan

[Graeme K]

If you want to make the flame more neutral you need to either provide more air or reduce the fuel but Jindi is right you are better off with a carbonising flame as long as its not too extreme. Often if your flame is too fuel rich you find you have trouble achieving your desired temperatures because so much of the fuel is not being effectively burnt.

[Stewart Townsend]

Well done.