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There is a JABOD in my backyard. Guess it's time to get to work


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It's a side blast, a lot like many of the others I have seen on this site.  Basically made from scrap 2 by 4 and plywood sitting in my shed.  The air supply comes from an old bathroom  exhaust fan.  I used some red brick and some fire brick to create a place for the fire and filled the box with sand, because that's what I had to hand without digging holes in the ground.

I was going through wood and charcoal at a ferocious rate, and I wasn't getting really good temps, so I need to learn fire management.  

At any rate, me and the boy got to bang on some steel today, so it was a good day.

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11 hours ago, Paul TIKI said:

a place for the fire

That would be a fire pot. Going through too much charcoal is an indicator of too much air. How are you controlling the air blast? Another hint the steel is in the fire at a steep angle and probably too low in the fire. If you remove the end block and make the fire a little deeper should help. What kind of charcoal are you using, from the picture it looks like some BBQ briquets in there, which are not the best for forging. I don't know if you have seen this thread but it will help with fire management, it's mostly about coal but the same principles apply to charcoal.

For just starting out you have a good looking JABOD and with some minor tweaks it should get the job done.

https://www.iforgeiron.com/topic/30887-forges-and-fires/

 

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Well, I'm really not controlling the air at all right now.  It was kind of a struggle just getting everything hooked up so that I had air going through the tuyer at all.  As far as the fuel, yes it was briquettes because that's what was on hand.  I also fiddled with some cedar chunks that I had laying around.  I wasn't expecting major results, just looking to find out what I don't know so I can figure out what I should be searching for.  

Weather dictates that I have to break things down for the week.  When I reassemble everything I'll make some adjustments

I think I have an ac speed control somewhere around the house.  I'll see if that will work with the blower.  It's tinkering I can do when it's raining.

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Most grocery & big box stores carry hardwood lump charcoal which is a better fuel. Or a lot of folks make their own charcoal. A lot of threads about that. Being able to slow down the air blast will conserve fuel and get you a much hotter fire, with charcoal I can melt steel and make fire welds. With coal air makes the fire hot, the more air the hotter the fire. But with charcoal too much air actually cools the fire down to the point of blowing the fire out.

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I use a ball valve on the AC mattress pump that was my air supply before I got an actual blower. There's also a picture somewhere on the forum of a waste gate made from conduit parts but I don't remember where. If I locate it I will let you know. 

 Also you may want to bring the brick that is lying across the bottom bricks of your fire pot level with top of the box. 

Pnut

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Thanks for all the advice folks!  That gate looks really cool.  It gives me some ideas on how to control the air on mine, though I will probably build the gate closer to the fan.  I really should have included a picture of that in the first post on the this thread. 

I found a 20lb sack of lump charcoal at Menards for 6 bucks for the next time I fire it up.  The thread about where the sweet spot in the firepot is makes a lot of sense and explains a lot of stuff I was seeing vs what my assumptions were.  So now I know I have too much blast (most likely), I need better fuel (got it), and I need to fiddle a bit with the brick placement in the JABOD.  

I also discovered that I might need a hood of some sort to help deal with the wind.  We got some fire fleas jumping around and I need to find a way to monitor and stop that for the dry months.  I'd hate to be the cause of fires in the fields out there.  The farmers might not like it :)

As far as controlling the blast:  I have a length of Hand rail from a treadmill I tore apart as the tuyer.  It has a 90 degree bend and I have that rotated down to allow my blower to sit on the ground.  A length of PVC pipe  acts as a connection between the 2, and it is a simple matter to slide the pvc up and pull out the blower.  would a hole in the side of the pvc pipe reduce the amount of blast I am getting?  Because I could drill a hole through both the PVC and the bent pipe and then rotate the PVC to open and close the hole while everything is connected.  I don't really get the fluid dynamics all that well, but I wonder if that could work.  I can add a picture of what I have later today.

Thanks again 

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Yes, you can bleed off excess air to control your blower. I've seen some great ideas on here. Shutter or gate works great! I decided on a small DC motor and controller for my set up and have had no trouble with its functioning. I have the added ability to blow full blast to clean ash from the gruyere before I start for the day. Do you have enough pressure with your fan to forcefully blow out your tuyere?

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18 minutes ago, Paul TIKI said:

I will probably build the gate closer to the fan.

The best place for the gate is where it's easiest to reach. If you have to bend down, twist your upper body, and corkscrew your wrist to adjust the blast, you're not going to adjust the blast nearly as much at you should. If the gate is right by your hand, you'll find yourself continually tweaking the blast whenever necessary, often without even thinking about it.

This is the same reason I have my hammer rack right next to my anvil on the hammer hand side: when I want to switch hammers, the one I want is always right there. No time, effort, or brain power wasted on hunting around. The last is most important, as I have so little to spare.

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If I drill in to the side of the pvc and the steel pipe underneath, that would put control of the blast much closer to hand.  That's if that method would work at all well.  A simple twist to close the hole or holes and you get full blast.  Another twist to align the holes and the blast gets reduced, slight adjustments to add finer control.  To shut off blast, lift the pvc and let it swing down off of the fan opening.  Or am I way off base and this won't give me nearly the control I need.  

It would be simple enough to just stick a ball valve in line on the PVC pipe, but I don't want to spend the money right now (yeah, I know 4 bucks won't break the bank.)  There is kind of a bet between me and my wife that I could get this going without spending a dime except for on fuel.  So far I have managed with what was lying around.  That 4 bucks is a point of pride !!!  So much so that the connection between the fan and the PVC pipe is made from an empty sports drink bottle!

 

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The gas grill is going to be my son's forge.  We have one, just need to fill it and hook up his blower.  That's going to require some problem solving as his blower is a nice hand crank Buffalo Forge blower so we need to neck it down to whatever tuyere he uses.  The JABOD above is showing us several instances of what to do and what not to :)

Believe it or not, this is the kind of problem solving that I love to do, so even if it's not working, I'm having a ball finding out.

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There is always the: Take a board and drill a hole for the tuyere pipe. Concentric to that pipe take a piece of ductwork the size of the blower outlet and cut tabs and screw it to the board.    You can gunk it up with silicon caulk if you less leakage.    

I've also seen people use the rubber plumbing pipe reducers on the blower connection.  Shoot one time in extremis we used a wet blue jeans leg bailing wired at the blower and tue pipe.  (Campout where the connecting pipe got forgotten! Trashbag and duct tape would have worked...)

No reason you can't have two JABODS!

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Two bits of wood, a drill, some staples and some duct tape and that problem is solved!  Thanks!  We shall have 2 JABODs in the back yard and the wife will be annoyed :)  

I have hopes that by using a hand crank blower that I can balance things so both arms get a workout. B)

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Ya'll should probably give me 50 lashes with a wet noodle as I forgot pics, but....

My son and I got the grill forged built up and fired up.  The body is one small propane grill with the guts torn out.  Soft firebrick used as the bulk of the fire pot then packed around with sand and unscented cat litter..  Side blast with about a 3/4 inch steel pipe (ganvanization removed) for a tuyere.  Air supply is a nice Buffalo Forge hand crank blower.

Had a lot of issues with getting the temps up to where I wanted them.  This time I used actual lump charcoal for fuel.  Very few fire fleas (yay), but it just did not seem to want to get hot.  I noticed a good improvement when we shifted a brick on the side of the fire pot opposite when the tuyere closer and built up the pile of charcoal higher, but it was still tricky.  We also noticed that we didn't quite align the hole for the tuyere pipe quite right and it was angled slightly up.  This was allowing debris and ash to block the pipe and we would be doing fine, move something, and then much less heat.  <_<  So my guess is tuyere placement, and maybe too small a pipe with a lot of air leakage maybe?  I don't think we got anything near hot enough for more than just simple deforming metal.  

So some tinkering before the next fire, and I promise I'll get some pics.

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Paul, take some measurements of the H,W, and D of firepot along with the vertical and horizontal location of your tuyere too. I'm having great success with my set up and we can at least compare. My tuyere is 1" pipe. I'd try that as your first mod. See if that doesn't get some more air into the pot.

I have noticed that when I have had trouble getting things hot, I had an obstruction in the tuyere. Softbrick (IFB) will slag and melt into blockages. My 2800s are melting down around the tuyere. 

Also, lump charcoal from the store does have foreign matter mixed among the charcoal which will melt into blockages. I have pulled out pieces of limestone, melted brick, plastic and a chunk of what I think is a mica-type stone.

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4h by 4w by 8 long for the firepot.  The pipe is down angled at about 15 degrees and is 3/4 inch pipe (I think), which may be part of the problem.  I know charcoal doesn't need a ton of air and I had too much in my other build.  Another potential problem is the way the blower is hooked up.  from the Tuyer back it goes from 3/4 inch pipe to a funnel to a standard flexible dryer duct and then to the blower.  It just kind of sits there so there is a lot of room for air to escape and not go through to the fire.  I'm thinking a liberal application of duct tape will fix that.  I need to be careful because I'm trying to think in terms of modularity.  The duct was originally acquired for use with my son's hand crank Buffalo blower and what I come up with needs to be able to come apart so I can switch between air sources.   Time to get creative with that.  I may have had better luck if I just stuck to the hand crank, but I'm out of shape and didn't want to work quite that hard. 

I inspected the Tuyere after everything cooled down and there was no blockage except a bit of ash which blew out with a puff of air down the duct.  Didn't look like there was any debris in the bottom of the fire pot.  Yesterday, I did not use briquttes, just regular lump charcoal broken down to about walnut sized chunks.  I used about 3 lbs worth over the course of 3 hours farting around yesterday.

I'd go test some stuff today, but there is a wind advisory.  Playing with fire not recommended outside.

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Glad you posted this, looking to complete something similar next week.  Once I get it up and running, I'll add some pictures and share.   I do have to say, you are a bit crazy working hot metal in bare feet.  Can't imagine that is going to go well in the long run. 

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that was my son in that pic.  I  hadn't noticed he was barefoot and fussed at him when I noticed.  There is a reason why males under 25 have much higher insurance rates.

Good luck on your build.  It's easier than I thought.  The Grill is actually better for me right now because wind and rain get blocked by the lid.  Looking for another gas grill to make another and keep the wood box on standby for larger projects since there is more area to work with.

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I just haven't had the time to try that one scrapyard I found.  At .20 per pound that would be maybe 2 to 4 bucks for a good grill.  I'll take that price.  Maybe I could even find a good hunk o steel for another anvil for the boys. 

Now, we did get a chance to got start unloading some stuff one of my boys had in a storage unit   2 55 gal drums and some really heavy chocks they use for those 20,000 lb rolls of steel.  If I could figure a way to mount them it may make some sort of anvil.  He also has a couple hundred lbs of scrap ends from his work out there as well

I think I have a handle on my airflow problems now.  Got a lot more airflow and therefore hotter temps, but without eating up too much fuel thanks to the miracle of duct tape.  I was able to spend about 3 hours forging yesterday on maybe 2 to 4 lbs of charcoal.  A few more tweeks and I may be good on that score.  I used the tuyere from my wooden box and attached it to the smaller tuyere on the grill forge.  If I drill the holes I'll have even more fine control.  I have some ideas on more future improvements but I'll wait until I get good with what I have

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On 11/18/2020 at 3:45 PM, wirerabbit said:

Softbrick (IFB) will slag and melt into blockages. My 2800s are melting down around the tuyere. 

Just curious why you would use relatively expensive IFB for this type of forge.  Were you trying to protect the tuyere from heat?   Standard fire brick is much cheaper and in general is probably better suited to this application.

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