Review my forge

[Brian Evans]

I made this forge out of an old cast iron sink, metal gardening stakes, fire bricks, pipes and a repurposed vacuum. 

You don't see in the picture but the back of the sink is to be used as a top for it to help keep in the heat. And I did elivate the higher over the air vent. I use coal as fuel. 

If anyone has any tweaks or tips on how to improve it I would be grateful.

Thanks

[JHCC]

Couple of things:

1. Why such a long forge? Realistically, it's pretty hard to work anything much longer than 6", but it looks like you've got something four times that length.

2. Do you have any provision for adjusting the airflow from your vacuum? 

3. This looks a lot like the commercial Whitlox forge, which is designed for burning wood. Why burn coal in a wood-burning forge?

 

[C-1ToolSteel]

Well, what is its intended purpose? I would love to have a forge like that for heat treating large blades, but not much else. In blacksmithing, even for large objects, you only need to heat the area that you will have time to forge in one heat. Once it is too cold to hammer, it goes back in the forge. A forge that heats way more steel than you can forge in one heat is wasting fuel.

Oh, looks like JHCC just replied.

[ThomasPowers]

Actually heating more than you can work damages the steel in larger blades: Decarburization, grain growth and scale losses for examples.

Now if you are twisting pickets a long heat is useful.

Can you evaluate how good something is for a purpose if you are not given the purpose?

[Brian Evans]

I did make it so I would be able to heat treat blades. The bricks are moveable and the airflow is guaged by a gate valve near the vacuum. The piping is threaded and designed so I can use half of the forge if desired. 

After trying one blade I decided to start with smaller things like wall sconces and wait till I get better. 

Should I make a different forge? And only have one fire pit like I see in many forges?

[JHCC]

1 minute ago, Brian Evans said:

I did make it so I would be able to heat treat blades. The bricks are moveable and the airflow is guaged by a gate valve near the vacuum. The piping is threaded and designed so I can use half of the forge if desired. 

I will leave it to the bladesmith people to address this, but my understanding is that you don't even need a full-length forge to heat treat blades.

2 minutes ago, Brian Evans said:

After trying one blade I decided to start with smaller things like wall sconces and wait till I get better. 

You have chosen the path of wisdom.

2 minutes ago, Brian Evans said:

Should I make a different forge? And only have one fire pit like I see in many forges?

Check out the JABOD (Just A Box Of Dirt) threads for a great low-cost way to build a forge. You could probably convert what you've got fairly easily, especially if you use the vacuum and gate valve. Another option is the recent JAPOB forge (Just A Pile Of Bricks), since you already have the firebrick.

Keep us posted!

[Brian Evans]

1 hour ago, JHCC said:

I will leave it to the bladesmith people to address this, but my understanding is that you don't even need a full-length forge to heat treat blades.

You have chosen the path of wisdom.

Check out the JABOD (Just A Box Of Dirt) threads for a great low-cost way to build a forge. You could probably convert what you've got fairly easily, especially if you use the vacuum and gate valve. Another option is the recent JAPOB forge (Just A Pile Of Bricks), since you already have the firebrick.

Keep us posted!

I will keep you posted, I'm buisy the next few days though because of work. 

[Tommie Hockett]

My forge is about that big and I burn charcial in it. However my wife and I forge out of opposite ends. Also I have decided to build a couple of side blasts for us or to try actual coal. The ashes keep clogging up my tuyere If i forge for longer than an hour.... Not sure if that is helpful or not... just my experience so far. I have nothing to add on heat treating.

[Brian Evans]

I use charcoal to start the fire then go to coal, I find coal burns more cleanly and evenly (versus charcoal). Do you have a lot of heat escaping in yours? That is my main worry. I want my forge to be efficient. 

[Tommie Hockett]

I really dont know what to tell you there buddy... I cant really tell that it does. But I am a noob also... 

[Glenn]

Always remember to use the repurposed vacuum on the blow setting. 

You may want to lower the vacuum below the level of the forge. When no air is moving into the fire, the air pipe COULD fill with gasses and when you start blowing air again, there could be an ignition and explosion in the system. It is not uncommon with bellows, etc.

Fuel does not make the fire hot, AIR makes the fire hot. Only use the amount of air necessary to get the amount of heat you need from the fuel you are using. If the damper system does not work to your scarification, then leave an air gap of 3 or so inches in the piping. If you want more air, aim a little closer, for less air aim not so close.

I would like to see the way the air enters the fire from the bottom of the forge, whether it is in one spot, or via a T, and then exactly how the air is allowed out of the pipe in the bottom of the forge.

[Charles R. Stevens]

Coal Slag loves fire brick... it sticks like glue. 

You have built a beutiful forge suitable for heating large scrolls with wood, unfortunantly from personal experiance it's not an effecent desighn for either charcoal or coal. 

Tommie and Brian,  I will be happy to answer questions about side blasts. I even have a chart some where related to tuyere size and fire deapt for coal forges, and recommended stock ranges. 

The simple Iron Age style forges with schedual 40 pipe (7/8") tuyere are good to about 1" stock and a 6" of dorgable heat zone. I actually like the double action bed pump for charcoal as it's quite. Look at bath fans, drier blowers and high efecency furnace exaust blowers for quite mechanical air. 

[Tommie Hockett]

13 minutes ago, Charles R. Stevens said:

Tommie and Brian,  I will be happy to answer questions about side blasts. I even have a chart some where related to tuyere size and fire deapt for coal forges, and recommended stock ranges. 

Thanks Charles. I will most definetly take you up on that offer... After some sleep if I hurry I can get 2.5 hours before the next job rolls around lol

[Charles R. Stevens]

Happy to

[Brian Evans]

14 hours ago, Glenn said:

Always remember to use the repurposed vacuum on the blow setting. 

You may want to lower the vacuum below the level of the forge. When no air is moving into the fire, the air pipe COULD fill with gasses and when you start blowing air again, there could be an ignition and explosion in the system. It is not uncommon with bellows, etc.

Fuel does not make the fire hot, AIR makes the fire hot. Only use the amount of air necessary to get the amount of heat you need from the fuel you are using. If the damper system does not work to your scarification, then leave an air gap of 3 or so inches in the piping. If you want more air, aim a little closer, for less air aim not so close.

I would like to see the way the air enters the fire from the bottom of the forge, whether it is in one spot, or via a T, and then exactly how the air is allowed out of the pipe in the bottom of the forge.

Hahaha, I did that on accident once and I couldn't figure out why it wasn't working for a while. 

After I use my forge I most of the time take it apart so there is no chance of the gasses in the air vents. However I did not know that that could be a problem, glad I know that now. 

The air enters the forge by a t joint and two pipes. The air enters the fire by drilled holes in the pipe (the outer ends of the pipe are capped) . The holes are an inch and a half separated from each other. Originally I would have a grate above the pipe but it kept melting and after using it a few times realised that it would work without the grate.