Forge welding

[busterbuilt]

Im not sure if this is where I should post this discussion so please let me know if I am in the wrong place. I have built a propane forge from an 8.5L gas cylinder that has been coated with 50mm of Kaowool and about 2mm of furnace coat. It also has 2 x 1'' burners. When I attempt to forge weld a billet by hand Im not getting good results. A lot of the billet does weld but there is always ares where it does not. Im an absolute amateur, and Im wondering if the issue lies with the fact that Im trying to get the welds done by hand and not a press or the forge is not getting hot enough. I do not have a heat gun but I let the billet soak for about 30 mins after the forge is hot. Any tips or advice would be greatly appreciated.

 

[3fifty7]

What steel are you using, some don’t weld well to themselves or others.

Starting by hand, use a short stack say 50mm tall max, having all of your corners mig or arc welded tight will help too.

Are you using flux? Generally when the flux liquifies when you are very close to welding temps. Another trick is to poke your steel with a wire coat hanger, the point of the hanger will want to stick on contact at welding temp.

Of course the proper way to gauge temp is with a thermocouple and reader.

 

[Bob Denman]

Im not sure if this is where I should post this discussion so please let me know if I am in the wrong place. I have built a propane forge from an 8.5L gas cylinder that has been coated with 50mm of Kaowool and about 2mm of furnace coat. It also has 2 x 1'' burners. When I attempt to forge weld a billet by hand Im not getting good results. A lot of the billet does weld but there is always ares where it does not. Im an absolute amateur, and Im wondering if the issue lies with the fact that Im trying to get the welds done by hand and not a press or the forge is not getting hot enough. I do not have a heat gun but I let the billet soak for about 30 mins after the forge is hot. Any tips or advice would be greatly appreciated.

Thanks for starting this thread.
I have never used a forge: but I am really curious...

 

[busterbuilt]

What steel are you using, some don’t weld well to themselves or others.

Starting by hand, use a short stack say 50mm tall max, having all of your corners mig or arc welded tight will help too.

Are you using flux? Generally when the flux liquifies when you are very close to welding temps. Another trick is to poke your steel with a wire coat hanger, the point of the hanger will want to stick on contact at welding temp.

Of course the proper way to gauge temp is with a thermocouple and reader.

Hey mate, thanks for the reply . I will definitely give that coat hanger trick a go.

The two steels Im using are 1084 and 15N20 ?
Also I mig the corners and use borax as flux (the cheap stuff from supermarket)

Another thing I should add is I only have great big piece of mild steal as an anvil which I warm up with hot steel before actually hitting the billet on it. I want to buy an anvil but can’t really afford one. But do you think that would affect the process very much?

 

[Stacy E. Apelt - Bladesmith]

There are two major issues with forge welds.
1) The primary issue is the billet is not hot enough, it has to be at welding temperature right through the middle. Use a coat hanger and poke the fluxed billet while in the forge. If the coat hanger metal fuses to the billet nit is ready to weld. It needs to be in te bright orange-yellow hot range to weld. red won't work.
2) Too much pressure when welding., Start with gentle hammer blows or pressing. After the billet feels and sounds solid, increase the force.