|Mike Schmoker (Wolfe)
Post Number: 6
|Posted on Wednesday, November 18, 2009 - 6:27 pm: |
Although I normally use a gas forge, I do have a Sears Early Ratchet(coke/coal)Forge circa 1915 thats in really good shape. The question I have is that when using the coke forge every so often when I wet the coke down with water I see a flash of light & hear a thump sound from around the bottom of the forge near the clean out cover. Can anyone tell me the reason or why this happens & possibly why its happening? Michael
|Dick Nietfeld (Shady_grove_blacksmith_shop)|
Post Number: 52
|Posted on Wednesday, November 18, 2009 - 11:57 pm: |
Mike, it is hard to say for sure what happens. Normally a thump and flash in that area is due to a buildup of coal gas, but since it happens when you put water on the fire, it could be steam. I've seen many a forge table or fire pot that has been cracked by watering down the coal. If yours is lined with clay and you limit the water so it doesn't get down to the fire pot, then you might be OK using water. If it were mine, I wouldn't put water on any cast iron forge table or fire pot. If your coal is mainly fines you might need to use a little water to hold the coal together enough to coke up, but I'd put the water on the coal in a bucket, drain the water off the coal before putting it on the forge table.
Personally I use Pocahontas #3 coal and do not wet it down. It works great that way. I've watched many a great blacksmith demonstrators that do not water down their coal. Some might do it at their shop, but certainly not on someone else s forge do to potential breakage. Also I wonder about your use of the word "coke". Normally you wouldn't put water on coke whether it is purchased coke or coke that you have made. Water is only put on green coal and is generally for the purpose of helping it coke up. A lot of coal doesn't need water to help it coke up.
|Mike Schmoker (Wolfe)
Post Number: 7
|Posted on Thursday, November 19, 2009 - 4:46 pm: |
Dick, Thank you for your reply. The coke that I'm using I cooked from green coal which around here is not a really good grade but its what I can get. I've mostly been using the water on the coke to keep the fire from spreading out too much but after reading your post I will be changing my methods.
|Ken Scharabok (Ken_scharabok)
Post Number: 409
|Posted on Friday, November 20, 2009 - 1:21 am: |
As noted, water can be over done. For example some extinguish a coal forge by pouring water over the coal. This can protentially crack the pot if it is still quite hot. It also mixes with the sulfur in the coal to create a mild sulfuric acid, which then eats away at the metal.
Dick didn't say not to use water to facilitate coking, but rather to use it judiciously.
|William "Bear" Britton (Blacksmithbear)
Post Number: 9
|Posted on Friday, June 04, 2010 - 9:06 am: |
Could it be that the water breaks down past the steam stage into its components, Hydrogen and Oxygen, which causes a small "explosion"? I have had the "Thump" happen occasionally when watering the fire.
|Grant Sarver (Nakedanvil)
Post Number: 1
|Posted on Saturday, June 05, 2010 - 8:58 pm: |
Water gas is a synthesis gas, containing carbon monoxide and hydrogen. It is a useful product but requires careful handling because of the risk of carbon monoxide poisoning. The gas is made by passing steam over a red-hot hydrocarbon fuel such as coke:
C + H2O → CO + H2
|Grant Sarver (Nakedanvil)
Post Number: 2
|Posted on Saturday, June 05, 2010 - 9:00 pm: |
it didn't like that character:
C + H2O ---> CO + H2
|Will Mc Donald (Backyard_blacksmith)
Post Number: 129
|Posted on Thursday, July 08, 2010 - 1:57 am: |
there are stories about the old timers, (or their apprentices, rather) blowing out their bellows as a result of careless fire handling. too much green coal heaped on too thick, and wet so that it can't get very hot very fast creates huge quantities of volatile smoke: so much so that with no air pushing it out and not enough oxygen in the firepot to burn it, a weak head of back pressure builds against the now mostly fused wad of coke. the gas needing somewhere to go, it actually pushes it's way unburned back down the tuyre, accumulating till the oxygen/gas/heat ratio is right and... BAM!
in the case of the old timers, this wouldn't happen till the expensive bellows was nice and full of fuel/air mix and as you might imagine, at times the results could be pretty darn lively. Let's just say that the bellows wasn't the only windbag that would have gotten kicked out on it's rear that day!
with squirrel cage blowers it's really nothing to worry about, just a little startling to see a pop of flame shooting out the intake. it's happened to me a gaggle of times, when it does i just tell the onlookers that its fire demons or forge indigestion or something entertaining like that and they calm down pretty fast.
well there you go, that's my bit. hope it helps and happy forging!