First Forge Build – Help Needed!

[DaveC23]

Hi All

This is my first post here, and after building my first forge I’m hoping I can get some help.  I’m new to all this, and for me it’s just a hobby, but before I can get started I need to get my forge working.  I’ve spent a fair bit of time doing my research,  and after finding a lot of conflicting information I decided it was better to just get on and try and build something to see what happened. The decision process for the design was based on the following: 

•     Unfortunately I failed to pull this forum out of the noise before I started the build

•    Across the internet there is an enormous amount of conflicting opinion, especially over the firepot depth. 

•    I can get the materials cheaply, and I enjoy the welding and fabrication process. I fully expected the first build to be a long way from correct – but that just gives me an excuse to build another!

•    I’ve not added a clinker breaker. I wanted this to be a weekend build, and decided the effort of a clinker breaker was not warranted on something likely to have bigger problems. Instead I have a fire grate.

•    I was planning to use charcoal as a fuel with the possibility of switching to anthracite if charcoal didn’t work out.  That’s because I can’t easily and cheaply get coke, coal is easy to find but it’s to smoky for the neighbours, and gas  doesn’t interest me. Accounting for this, I decided for bottom blast which I gather is better for anthracite although less good for charcoal 

•    The steel is ¼ inch throughout.  I gather ½ inch is better, but I can cheaply get 1/4 inch.  It’s also just for occasional amateur use. If I have to make another once in a while that’s OK. If I have to make lots, then it’s time for ½ inch!

•    I am using an electric inline blower. It’s max output is 750 m3/h. I have an electronic speed control as opposed to a gate valve so I can run it very slowly if needed.

Well, on first fire with charcoal, things didn’t work out so well:

•    The fire was far too low down in the pot on low fan speed

•    On higher fan speed I was amazed by the ferocity.  The fire seemed to move up (I think), but it burned through charcoal like it grew on trees and I think it was way to hot. I have not tried anthracite

•    There didn't seem to be  a happy "medium" fan speed. In fairness, I'm too inexperienced to know what I'm looking for

•    I didn’t try building up the fire higher than the pot, and I have not welded sides on the forge  yet.

Before I make MK II, it would be great if people could set me in the right direction.

I should add that  I’m planning on starting  small, so a modest size forge and fire will be more than ample for quite some time.

Thanks

David

[Frosty]

Welcome aboard David, glad to have you. If you put your general location in the header you might be surprised how many members live within visiting distance.

Without the major detail overload and long back story, do you have a question?

The fire looks good in the pic, is there a problem?

I'm not giving you a hard time David, you're kind of refreshing as a 1st. time poster. Most ask some complicated questions without any details to work with. And here you come with a bunch of details, so many I'm not sure what the question is, if there was one.

You're okay, I like you already.

Frosty The Lucky.

[pnut]

Charcoal does grow on trees;-) I'll refrain from offering any advice. Someone with much more experience should be along shortly. Your forge looks good to me and should work great with just a few changes in fuel depth and air flow. Good luck and good job on the build. 

Pnut (Mike)

Frosty, I believe he wants to raise the fireball to level with the table so he doesn't have to angle the stock to get it in the sweet spot.

Pnut (Mike) 

[Irondragon Forge ClayWorks]

Glad to have ya David. I always suggest reading this to get the best out of the forum. READ THIS FIRST

Looks to me you are off to a good start.

[ThomasPowers]

Where are the slots to allow you to put the rod through the hot spot for heating---it should be pretty horizontal.

Note you can fill the firepot with clay/dirt and check how it works at different levels for you.(place the grate higher up too.)

I don't know which of the 150 countries that have participated here on the World Wide Web you are in so I can't suggest a person to help you get started in person!

[DaveC23]

Thanks for the feedback, it’s really appreciated and it’s good to see that I’m not way of the mark.

In terms of my question, and indeed my forge build, I’d hoped it would run with the fire more compact and higher up. The idea being that I can then weld some sides to the table to heap more coals over the fire. As suggested in the feedback, I was hoping not to have the stock at such a steep angle and lay it horizontal.  There are all sorts of things I can experiment with like fan speed, raising the grate\base, the air vent size, or a rebuild to different dimensions. On the other hand, it would be good to know if that’s just how charcoal runs and there is nothing wrong with it and nothing to worry about.  If there is something I can do, I figure the experience available here can save me time.

In terms of what I want do, I’d say starting of small and simple – just basic skills on the end of ½ inch bar stock,  and hence why I was thinking the fire didn’t need to be so aggressive. Maybe a smaller firepot would help with this, buy maybe a smaller fire pot would not cut it at all ?

Thanks Again

David

P.S. – Yes a good point about updating my profile to give my location , although I tend to leave these things blank out of paranoia over internet anonymity. On the plus side it makes things safer, on the downside I can miss out on offers of help.
 

[Daswulf]

You'll want to bring the pot up and be able to place your stock In the burning coals. Bottom blast isn't the best for charcoal since it eats a lot of fuel as you are finding out. It can work but a simple side blast forge may be better. With what you have now you can do what Thomas suggests and raise up and shape the inner pot with clay. Fencing around your table will help you keep extra fuel on it. Remember to have cutouts to allow your stock to pass through. Raising the fire will help you burn less fuel and heat stock in the better zone in the fire.  I'm burning coal now and only experimrnted with charcoal when first working with the bottom blast forge I built. 

1/4" material is fine for the fire pot. 1/2" is overkill but hey, some people like overkill.

If you design a second bottom blast think of having a v or gully running through to be able to place stock in lower. Or have a shallower pot and use fencing around the table other that the pass through slots and you can build the fire up. You can also use bricks to contain and build up the fire, again leaving a pass through. Personally i feel the pot you made is a bit deep with no way to get more stock where you need it. 

[DaveC23]

Thanks Daswulf -  I appreciate the help.  I’ve just had a go at burning anthracite and I preferred it to charcoal. It seemed to have pretty much zero smoke and smell, lasted a lot longer than charcoal, and without the sparks. I’m also going to follow advice and make forge MK II with a shallower pot. I’ll build it to the same dimensions as my drawing above, but 3’’ deep rather than 5’’ deep, and I’ll  let you all know how I get on.

If anyone is interested, the fire below is in the same firepot as the top post, but burning anthracite rather than charcoal.  

[Frosty]

If a 5" pot is too deep partially fill it with fire brick, score and snap to size and shape. Easy peasy. If 3" pot isn't deep enough arrange fire brick around it to make it deeper. Laid flat split brick is 1 1/4" to 1 1/2" thick, full brick is 2 1/2" thick. On edge they're 4 1/2" wide.  You can find the fire depth you need easily enough WITHOUT rebuilding what you have now. Yes?

Frosty The Lucky.

 

[Irondragon Forge ClayWorks]

I'm guessing the grate you show in the last picture of the first post, fits flush down in the bottom of the fire pot. Here is what I would do. Build another grate that fits higher in the fire pot to however deep I wanted and weld in tabs on the box for it to set on. Could also make more grates to move higher and give you the depth that works best for what you are working on. Kinda like the adjustable charcoal grates in a BBQ. Two extra grates should give you the versatility needed/wanted.

[DaveC23]

Your both right of course, and with some imagination I can come up with something.  I had planned to get more done over the weekend, but ended up being distracted by looking at anvils (it didn’t go anywhere, but kept me entertained.)

[DaveC23]

Following advice I’ve created a second grate which reduced the fire pot depth to just over 3'', and I've also added a fence to the table.  The fuel is anthracite beans, and there are no other change to the pot form my drawing above. It’s no doubt an improvement, but I’m still finding the fire is lower in the pot than I’d hoped, and hence I still have to put the stock in at an angle.

 To show what I'm getting it seemed easiest to video it.  I've put the link below: 

https://youtu.be/36eeyi9dmpQ

The new grate is a reasonable fit, but no doubt some air is getting around the edges. I’m not sure if that matters, but whilst I’m experimenting I didn’t want to weld it in place. I’m hoping you can guide me further on how to get things just right. I could speculate, and the below seem like the immediate things I could play with, but getting advice from someone who knows seems like the best way forward

• Raising the great further, with more coals above the table
• Cutting a V groove in a rebuild  (as suggested), but this is unattractive as it makes things harder to fabricate - but OK if that's what's needed
• Playing with the fan speed
• Playing with the grate opening size

Thanks all

David

[pnut]

Let me once again say I'm not a very experienced smith but If I were standing in front of that forge I would heap coal above the top of the firepot and see if that fixes it. If that doesn't work I would increase the blast with coal piled up. It looks like you have to add more coal anyway. You need a few inches of coal above the work. That would be how I would troubleshoot the problem. It's going to take some experimenting to dial in your forge. Each one is different. You're going to have to find out how your forge works best for you. Sorry I couldn't be more helpful but what I said above is exactly how I figured out how to get the fireball where I want it in my forge. Good luck I'm sure you'll sort it out directly. 

Pnut (Mike)

If neither of those things work then maybe raise the grate.

[Irondragon Forge ClayWorks]

The fire looks good to me, although I use bituminous coal. Not sure with anthracite  but like pnut said mound the coal higher.

[Glenn]

On 5/8/2019 at 5:05 PM, DaveC23 said:

updating my profile to give my location , although I tend to leave these things blank out of paranoia over internet anonymity. On the plus side it makes things safer, on the downside I can miss out on offers of help.
 

Adding your location as a state name is usually generic enough to avoid paranoia. If not then a region of the country is good.

Play with the fire until you find the sweet spot, then raise the fire so the sweet spot matched the top of the forge table. Easy to lay the stock on the table top and hit the sweet spot that way. Use bricks to then raise the sides of the fire for the depth of fuel and fire you need. Extra fuel over the fire ball is there to both insulate the fire and to have replacement fuel for the fire. Fuel does not make the fire hot, air makes the fire hot. Use only as much air as is needed to get the heat you want from the fire. 

Separate the air supply pipe from the blower by several inches.  Air control is now simple, if you need more air, aim the blast more directly toward the air pipe. If you need less air, aim the blast less directly toward the air pipe. 

 

[Charles R. Stevens]

Charcoal and side blast forges go hand in hand. Charcoal and bottom blast forges have an uneasy relationship (more married with children less Adams family) I have built a successful side blast forge with a steel fire pot. 

[Frosty]

51 minutes ago, Charles R. Stevens said:

(more married with children less Adams family)

      !!

That's the best metaphor I've ever seen used for the comparison. Man I love you Charles, someday I want to sit and talk over coffee, beer or shoveling pucky. Whatever.

Frosty The Lucky.

[Charles R. Stevens]

I have a slide in camper in the planning stage for my Isuzu NPR. So I may just show up in your drive way (assuming the Alaskan roads have not fallen apart since you retired).

[ThomasPowers]

General region of the country helps if you mention which country.... "NW Corner" applies to Australia as well as the USA.

[Daswulf]

Dave, that looks better. And you can modify if needed as you use it more and learn more. 

[Les L]

Dave,

here is a picture of a 100 year old forge I’m working on  the fire pot is 10” long, 9” wide and 4” deep the cut out is 1” deep