What’s your air source?

Your good for charcoal, but coal would like an inch or inch and a half more from top of hearth to top of tuyere and more air than charcoal (any electric bed inflator or hair drier will be more air than you need, wile a double acting bed pump will be to little).

I'm using a hand crank blower from a very old sears catalog.

 

Ok, then one assumes we have enugh air. Try either building up the hearth, lowering the tuyere or trying to lay bricks around the fire to make it deeper. 

Alright, thank you. Going to try that now......

7 months from first board cut to first fire

Helped a friend to build a JABOD last fall. He didn't want to use it cause he wanted a "real forge"(a gas forge featuring every "don't" I've read on this site). After burning through lots of lpg without meaningful results he decided to give the dirtbox a try

 

Our sophisticated bellows setup. I was pleasantly surprised about how quiet that old Nilfisk vacuum cleaner was. Set up the hose to cover about 5% of the tuyere and used a piece of cardboard as an air flow reducer. Note the high tech twigs'n'tape splinting keeping the hose in place.

For a first project I melted/burned an old nail and some 20mm stock...

Flame ON! 

Frosty The Lucky.

Finally rebuilt the jabod. The first one was wrecked after a long period of rain. The stand sunk in the mud and dumped it splitting two boards. I still need to make the firepot a little wider and see how much it's going to shrink check but  otherwise I'm back  to work after putting it off too long.

Pnut(Mike)

 

Edited May 8, 20197 yr by pnut

Hoping to get some help improving/optimizing my JABOD. I built a box following Charles' method and today was my first good long day with it. I wasn't able to get a good heat on top of the fire I had to slightly bury the stock which at one point got it up to welding temps when I left it in a bit too long. Is that normal, or do I need to make some changes to my firepot? I also got some bitluminous smithing coal for the first time so I'm probably introducing some inefficiency there too. For instance I was adding the green coal on top of the fire instead of letting it coke up around the edges first. Did some searching here afterward and realized my mistake.

My firepot is 4 inches wide, 9 inches long, and 5 inches deep. The center of the tuyere(3/4" schedule 40) is 3 inches down from the top of the box leaving about 2 inches below. I have 2 pieces of hard firebrick standing the long way on top of the forge as a back stop. Should I make the firepot a little shallower? Deeper? I eventually would like to form the firepot out of fire clay once I learn the best configuration.

Do you have the bricks along the nine inch side of the trench?  A brick on either side of the trench lets you pile fuel on top of the work. 

I believe a trench works better for charcoal. 

What are you using for your air supply?

Pnut (Mike)

Yes they are along the 9 inch side. I  experimented adding bricks on the opposite side of the trench and that didn't seem to make much of a difference but I did not pile much coal on top of the work so maybe that's where I went wrong. My air supply for the time being is a hair dryer with a ball valve in line to adjust the flow of air. I will try to post a picture later when I am home.

You usually need a few inches of fuel on top. I'm by no means an expert but that would be the first thing I'd try. 

Pnut (Mike)

Thanks Mike I appreciate it I'll try again tomorrow. Between that and managing the coal better I should hopefully get better results.

I recently started researching how to build a forge and this is one of the first sites I came across, this is a very interesting thread!

im curious if this would work with the materials I have available, leaf springs and coil springs from a 1970’s 4wd f100. I’m interested in making larger (12-16”) blade knives, I know I can heat the leaf springs and hammer them flat then grind my shape out, but I would really like to be able to get my material hot enough to hammer to shape.

Is a jabod practical for this or would I be better off making a propane forge? From the little bit I have already read online I’m lucky enough to have most of the materials for both, would just need the insulation materials for a propane forge, and just fuel for a jabod. Also if I did go jabod would coal or charcoal be the better option for my purposes? 

Pattern welded Swords were forged in charcoal field forges with 3/4-1” sideblast tuyeres. So properly desighned it will work, is it best for your needs? I can’t say.  

A sideblast forge using clayed soil is free or very inexpensive to build. You can build one on  Friday after work and forge with it Saturday and Sunday. If you don’t have a “materials” stash, we are talking about $50-100 investment. If your good at scrounging then  we are talking free. 

You only heat a piece of steel as long as you can forge in one heat, so 6” is plenty, obviously heat treating is different but you don’t need welding temp.

now after geting your feet wet for cheep then you can figure out what you need.

 

2 hours ago, Lightbulb said:

I recently started researching how to build a forge and this is one of the first sites I came across,

Lucky you. I groped around the internet for a week or two before I came across this forum. Once you see how easy to construct and how well they work you'll be amazed at the jabod style forge. Not only are they easy to build, cheap,and work well they are versatile. You can change the depth, width, etc as needed. It's as simple as getting out the trowel or rearranging a couple bricks. It'll let you figure out what works best for you before fabricating a more permanent set up. When I make a more permanent set up it's probably still going to be a clay firepot forge. 

If you really do want to build a gas forge I'd still build a jabod. As Charles R. Stevens said above, "Build it on Friday forge on Saturday." , but a gas forge takesa lot of tinkering to tune the burner and get everything dialed in. There's lots of waiting on drying and curing etc. With a jabod you can be forging while you are waiting for the refractory to dry and supplies to arrive and so on.

Good luck.

Pnut (Mike)

 OH and to answer your question about the jabod getting hot enough the answer is yes. You can burn steel in it If you're not paying attention. You can do everything with a jabod you can do with any other similar sized forge, weld, forge, burn up stock into a sparking mess. It'll do it all ;-)

Thanks so much to the both of you! I only worried if it would work with my material due to the thickness of leaf and coil springs. I plan on using a torch to heat treat just the cutting edge as the large knives I want to make are for clearing heavy brush around our property.

i have a feeling all my future free time will be spent reading the massive amount of information on this forum, and if everyone is as helpful as you two have been I don’t think it will take long for me to learn! Thanks again! 

Are you afraid your steel is too thick or too thin to work in a JABOD forge?  I missed that in your post.  Swords have been forged in JABOD type forges for over 2000 years so any issues are having would probably be due to operator error rather than tooling error.  I have used a hole in the ground forge for working 2" steel when needed.

As to which would work better in your case: Are you in the city, suburbia, country? Are you in a country where it is easy to get propane or hard? Are you in a country where it is easy to get charcoal? Are neighbors an issue?  (Swords have been forged using charcoal for over 2000 years, coal only about 1000 years. Charcoal is a much cleaner burning fuel. Real charcoal not briquettes!)

 

I’m in the USA, Indiana specifically, I have a 12 acre farm so if I build any type of forge the neighbors would have no idea lol my house is almost a 1/4 mile off the road. I was initially worried about the thickness of a leaf spring being hard to heat up, but that is not a worry now.

what do you mean by real charcoal, not briquettes? Will the standard briquettes not work? That’s something I will need to look into.

Lump charcoal. You can make your own pretty easily in a fifty five gallon drum. The briquettes won't work very well. Lots of fire fleas floating around and there's a lot of additives in briquettes. The box stores sell lump charcoal until you can get to making your own. Look up semi direct charcoal making and there's plenty of videos online.

Pnut (Mike)

Yes, you need to cover your work with fuel, it insulates against ambient air so your work can heat faster and for less fuel. The other reason is keeping air off the hot steel, mix hot steel and the oxy in ambient air makes scale. Yes?

About using a trowel to make a JABOD, do NOT make mud, it takes to long to dry and shrink checks as it does. Just enough water that you can pack it hard with a mallet or similar is plenty. While I've never made a JABOD I've burned plenty of wood and charcoal to heat steel. I've never waited to light the fire, I tamp it hard, do any final shaping I wish and light it up, damp soil packed hard doesn't shrink check.

The closest I've come to a JABOD is a pile of dirt on an old kitchen table. I just shoveled a pile, scooped and tamped then built the fire.

Once you get the hang of managing a fire you'll discover they all work about the same with minor variations. Using wood is probably the most trouble, corn ain't bad at all.

Frosty The Lucky.

Frosty, I'm talking about a garden trowel. A little spade to change the shape of the fire pot. I should have been more clear.

Pnut (Mike)

Edited May 21, 20197 yr by pnut

Yeah, I wasn't taking issue but most folks wanting to work soil make it crazy too wet, even road crews. The word trowel often brigs to mind plastering or masons smoothing mud.

Frosty The Lucky.

No worries;-). The clay behind my apartment seems like it stays about the right consistency straight out of the ground no matter what the weather is doing. There's a filled in spring that keeps it just about right. The building I live in was called the Carlsbad mineral springs and sanitarium back in the thirties. They filled in the spring I don't know when. I've been wondering about sulfur content in the clay.

Pnut (Mike)

http://sites.rootsweb.com/~kygrant/carlsbad.html

This link says there was never any spring, but that the water was pumped from underground. 

 

Grant Co. Geology search

The first few of these look useful to know what is in your dirt. The first one looks like what I was trying to find, but it shows up blurry on my phone. 

Edited May 21, 20197 yr by Chris Williams
Removed typo

Thanks for the link. I didn't come across that particular one in the limited research I did into the history of the building I live in. I thought I was going on info from the proverbial horses mouth. A gentleman about 85 yrs old told me about the "spring" and it being filled in. The railroad drainage is still there so that explains the damp conditions. There's a newer storm run-off drain back there somewhere too. Any how I was worried about sulfur just because as I'm sure you know it's not good for steel and here in northern KY. not too far from here is big bone lick state park. There's mineral springs there and they're mainly sulfur springs. I wasn't too worried as you can smell the springs at big bone from quite a distance and I can't smell sulfur here. It did cross my mind because it's specifically detrimental to hot steel.

I'm not sure why that link doesn't pop up when I searched for info on the history of the building. Maybe the difference between Bing and Google. I use Bing usually.

Thanks for the link I don't want  to tell the old fellow he's wrong because he won't believe it and I don't want to put him off or offend him which I'm sure it would. I will tell him If I can catch him alone. I don't want to do it in front of anyone. I don't want to embarrass him or be disrespectful.

Thanks 

Pnut (Mike)