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On 6/23/2018 at 4:36 PM, the iron dwarf said:

you are less than 2 hours drive away from me

I'm saving up the cash to try and book in a course with your Copper Elf! My financial situation is far from ideal so please don't judge me too harshly...

On 6/23/2018 at 4:36 PM, the iron dwarf said:

...and probably less than 10 miles from other online helpful smiths....

....unfortunately despite my best efforts (googling, searching IFI, checking the BABA database), I can't find anyone local (essex) at all! I found a couple of commercial blacksmiths/bladesmiths nearby and dropped them emails but no luck.

 

 

Progress shots of my firepit legs below. The second leg matched the first reasonably well! Success. One more to go!

I fitted the new "proper" forge blower, although there were lots of less than ideal duct-tape joins while I gather together to different hose/pipe adapters I need.

Unfortunately I still burnt 4kg of charcoal in approx 2 hours, and am still struggling to get metal hot while I literally stand and watch the charcoal disappear before my eyes.I turn the air supply off between heats, but I find myself adding new fuel EVERY time I put the metal back into the fire because I lose so much so fast. I've tried varying the air flow (on a ball valve) between nothing and full blast and I have no ideas whats "right".

The new blower is this one: Link removed

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 Motor Type:External rotor motor / shaded pole
induction IP44

 Nominal Supply:230V 1Ph 50/60Hz
115V 1Ph 50/60Hz
400V 3Ph 50Hz

 Ancillaries:Inlet & discharge guards, spigots, inlet filters

 Materials:Fancase – cast aluminium LM6
Impeller – galvanised sheet steeel

 Finishes:Unpainted or stove enamel as std (black)

 Mounting Options:Foot, Inlet & discharge drillings

 Noise Levels:75.5dB(A) Free Air, 1 Metre

 Weight:4.8Kg/10.58lbs

 

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Nobody who's opinion is worth paying attention to is going to judge you by what you can afford to spend. Those of us with experience are masters at making do with what's available. Your fuel consumption to useful heat problem is what you're building your fire in. Charcoal needs a deeper fire especially a bottom blast fire but you need to have your steel IN the pile NOT on top of it.

Check out the JABOD threads started by Charles Stevens. Charcoal works much better in a Side Blast forge and of the many types the ones recently pictured work best. It's an ancient design, stood the test of time and is easy to build and use. A side blast will burn almost anything flammable as a forge fuel, many 3rd. world smiths burn dung and perform all the blacksmith's work. 

I'd recommend you start out using smaller size stock, flat bar (strip stock over here) isn't the easiest to forge. Keeping it going straight is a skill in itself. Round or square hot rolled of moderate thickness, say 10 mm to 12 mm is a good place to start. It's large enough to hold heat so you get a little hammer time between heats but small enough you can get a piece made without having to spend a long time at it. Make sense? Frustration is your enemy so set yourself up for success, we'll help.

No apologies Jon, we're on your side. 

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34 minutes ago, Frosty said:

Nobody who's opinion is worth paying attention to is going to judge you by what you can afford to spend.

No, we judge you on spelling and grammar.

KIDDING!!!

35 minutes ago, Frosty said:

Those of us with experience are masters at making do with what's available.

This is very true. 

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6 hours ago, Jon Kerr said:

I still burnt 4kg of charcoal in approx 2 hours, and am still struggling to get metal hot while I literally stand and watch the charcoal disappear before my eyes.I turn the air supply off between heats, but I find myself adding new fuel EVERY time I put the metal back into the fire because I lose so much so fast. I've tried varying the air flow (on a ball valve) between nothing and full blast and I have no ideas whats "right".

Fuel does not make the fire hot, air makes the fire hot.  Charcoal takes a deeper fire to make embers. The metal will be placed into the embers to get hot. The JABOD is more economical to run and a better choice for charcoal.

Fire maintenance is a skill that is learned. When you finally get it to work,  you will wonder why you thought it was so difficult. 

Please post a photo of your current forge. It will help us see what you are doing and provide better answers.

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Sorry gents, I AM running a JABOD. I've followed Charles' design pretty much to the letter.

I've upgraded to the forge blower shown above (NOT PICTURED), attached to a 1" ID Tuyure.

I wonder whether the size of my charcoal is now an issue? Some pieces are 2" x 3" pieces? I try to break it up a little as I go by bashing it with my rake.

Since the edges of my fire bowl have broken away with use, the size of the bowl is growing a bit. I guess that could be one of the problems?

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the details posted with your blower show it as 3 phase, if I had known I would have dug out one of the many 3 phase ones I have, they would be going cheap.

this weekend we are doing an event where we will be demoing and doing a have a go, it is a land rover event near northampton.

if you know someone interested you may be able to get a free lift and for the cost of admission watch us, ask questions and learn a bit

john ( copper elf ) will be there and smoggy from here

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Yeah, you want to break your charcoal up, I prefer it down to say 12-20mm. The greater surface area per volume means faster chemical reactions which means it burns hotter and consumes the oxy sooner. This makes a hotter fire for less depth and helps prevent scaling in the fire. Hot steel will scale when it's exposed to the air but we don't want it scaling IN the fire. If it does you're putting it too close to the air blast.

Another brick wall across from the fire back wall to it forms a trench will help preserve the fire pot(?) and help conserve fuel. 

Frosty The Lucky.

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16 hours ago, the iron dwarf said:

this weekend we are doing an event where we will be demoing and doing a have a go, it is a land rover event near northampton.

Ah! Unfortunately I can't make it this weekend which is a real shame as I'd have popped up and said hello.

15 hours ago, Frosty said:

Yeah, you want to break your charcoal up, I prefer it down to say 12-20mm. 

Another brick wall across from the fire back wall to it forms a trench will help preserve the fire pot(?) and help conserve fuel. 

I'll try breaking it up- I hadn't realised it needs to be so small! Any tips for this? I assume the dust etc is bad, so you don't want charcoal coated in dust produced during the breaking up?

I've seen examples of a mesh cutting table, where the dust/tiny bits drop through to a lower layer. Is this the best option?

Would you use a hand axe or just smash with a hammer?

 

I'll add another firebrick as you describe to try and achieve the "trench". That sounds like it will work great for the long stock I'm using.

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A lot of the videos of Japanese swordsmiths show them chopping up their charcoal with a small hatchet.

(FYI, a Japanese hatchet looks like a beefy machete.)

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It's just charcoal, you can break it with your hands it's so weak. A blade works better than a smasher like a hammer or rock. Charcoal dust isn't an issue put it in the fire. However, try not to make more dust than necessary. Maybe make a small wooden box to break it up in. I'm visualizing a short length, say 12"-18" of 2" x 6" (framing lumber) with a rim say 4" high around it to keep chopped charcoal from being thrown away. Break the charcoal up with a small hatchet, cleaver, Ulu, or whatever you make. It's not something technical a little imagination should do it. 

When chopped dump the box into a bucket or whatever you're using to hold charcoal at the fire.

Make sense? 

Frosty The Lucky.

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In a pinch you can use tongs to break it, just a little squeeze will do. That's especially useful if the piece is already in the fire. Also a large piece on the top of the fire can create a chamber which is sometimes useful. As the fire burns that piece will spontaneously break up into smaller bits without your intervention. 

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I 3D printed a nozzle and adaptors for my new forge blower. Attached a picture of it all hooked up.

Also attached a pic of my current set up, for what its worth.

Took Frosty’s “trench” suggestion and added the extra brick. Hopefully that will help my consumption issues.

Will try breaking the charcoal up next time and hopefully that will solve my metal heating issue.

Hopefully with the trench, new blower and smaller charcoal next session will be less frustrating!

3 hours ago, Frosty said:

Make sense? 

Perfectly, I’ll do as you describe thanks.

What about really tiny chips (are these called “fines”?)? Do I need to seperate them? I’ve seen charcoal prep tables consisting of a series of metal meshes to let small bits drop through.

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Well, I finished the 3rd of the firepit legs and handed them over to my friend. He's got them welded up straight away and is really pleased.

First happy customer. I feel like a real blacksmith :D (I say customer in the loosest sense, although he did pay me with four bags of high quality charcoal!)

The pictures make it look small, but its actually huge. The dish is over 3 1/2' feet diamater, and each of those legs are forged from 1 1/2" by 1/2" stock.

(Note. The dish was obviously not forged by me, only the legs. He purchased the dish online.)

In other news:

My fire management is improving, slowly. I used approx 3kg of charcoal to forge the last leg, which is an improvement. It still seems like a lot. I'm learning where the sweet spot is in terms of air flow for heat. Next step is to wire up my new foot switch so the air automatically shuts off when I step away from the forge to the anvil.

Next session I'd really like to try some bottle openers with a dice-twist.

My fiance's birthday is coming up this month, and our wedding is in August. Does anyone have any really nice gift ideas I could forge?

Firepit(1).jpg

Firepit(2).jpg

Firepit(3).jpg

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To deal with heavy logs being dropped/thrown onto the fire I think I would have made each leg terminate at the bowl with a scroll that would contact the ground and take the weight/impact.  Of course if it's a light duty item, not an issue!  Is there plans to add a drainage hole in the center?

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Like I said, the picture makes it look smaller than it is. Those legs will be easily strong enough to survive logs being thrown onto the fire. Scrolls to contact the ground is a good idea though, and definitely something I'd consider in future if I made a smaller version with thinner stock legs.

I believe my buddy has already added a drainage hole, and has purchased a small circular grill to add into the bottom to allow some ash to settle out.

 

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Having heard rumours that your climate receives precipitation from time to time (and that it is good practice to flood a fire before leaving it), I was thinking that a drip hole might be useful.   

Good to know it's over-engineered!   (I once built a tent frame, post and beam mortise and tenon) that we hung a porch swing on and had 500# of folks on the swing...at a campout...)

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Take a look at Mark Aspery's video on forging a pass-through handle corkscrew from a single piece. If well-done, could be a great gift and cool way to open the champagne.

 

Edited by SFC Snuffy
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Great suggestion thanks Snuffy! Anyone got any more?

 

26 minutes ago, ThomasPowers said:

Good to know it's over-engineered! 

The flaming curmudgeons had me worried for a second so I even had to break out the pencil to prove it.....! (No disrespect to TP! All in jest.)

For those interested (probably not many...!):

Bending Stress is S=My/I (where M is Moment, y is distance from neutral axis, and I is Second Moment of Intertia).

For a rectangular bar as in my firepit legs, I=bh^3/12 (where b is the width, 40mm, and h is height, 20mm).

Since we're interested in maxiumum allowable mass in my firepit, we can rearrange S=My/I to give M=SI/y.

The yeild strength of mild steel is in the region of 370MPa (so S=370MPa).

Therefore, the maxumum allowable Moment M= 986642.

Moment= Forcex distance, and Force=massxgravity. So F=1973N.

Therefore...... The allowable mass on each leg before bending is (believe it or not) 200kg. Since the firepit has 3 legs, thats a total allowable mass of 600kg.

There's no way we'll be putting more than 25kg (50lbs) of wood in the firepit at any given time, so we have a healthy Factor of Safety of 24.

You never know... someone might one day wish to do a similar calc.

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