What the heck happened?

[Reoryx]

So last Saturday I'm merrily forging away in the shop. I'd finished for the day and though I'd make a little extra coke for my next fire. I put some green coal on like normal and watered it down a little, set the blast on low and sat down to think, when I got up and killed the blast there was an unbelievably loud bang and a white/blue flash. The concussion made my ears ring for about 10 minutes. ----- I think I remember reading about this somewhere but can't remember what the cause is. Any input will be greatly appreciated.

Thanks,

Jason

[Woody]

Jason:

It is called an explosion. In the coking process, the gasses produced are extremely flammible and much of them goes unburned. Unburrned flammable gases collected someplace probably in the vent pipe and when they found their way back to the fire and ignited with explosive results. Glad you were not injured. I once left my rivet forge for lunch, put a block of wood in the fire and covered it with green coal and patted it down with a shovel. When I finished lunch, I came back fished the block of wood out of the fire, ignored the smoke wafting out of the intake for the blower. There was a boom that rattled the windows in the house, caused me to jump clear over the anvil and the neighbor lady to come out and see if I was ok. The unburned gases from coal are not only very flammable, then also contain numerous toxic components.

Woody

[irnsrgn]

Now you know what Blacksmith Wet Shoes Syndrome is. LOL

[Dave Shepard]

That explains some of the symptoms I have been getting out of our forge at the museum I volunteer for. We always make a little extra coke for the next group so they can start right up in the morning. I have noticed that with the latest batch of coal, which seems to have some anthracite in it, that when I stick a poker in to stir it I get little flare ups after it has been cooking for a bit. We have a blower in our vent stack, so that may be why we haven't had a good explosion yet. I will have to keep this in mind in the future, thanks.

[6013]

Your forge backfired, just like your truck does occationally. Gasses built up and with a little extra air, a spark, and it pops, usually just enough to get your attention. But sometimes it takes more to get your full attention than at other times LOL.

[Reoryx]

Thanks for the feedback guys, I figured that's what it was that happened but I wasn't sure and I didn't think it would be anywhere near that dramatic. The shop is only 9 x 20 so when it went off I nearly launched myself through the wall. LOL - It would have saved me putting in a window.

Jason

[Glenn]

Whitesmith and I were at a demo with Paw Paw, Jock, and others and were trading stories during a lull in the action. BANG ! Sounded like a 12 ga going off at real close range.

Jim's demo forge had backfired. No damage to the bellows, but it was definately a check for who had a heart condition. Even though this was an outdoor demo it took several minutes to regain our hearing. We guessed that there was a shift in the wind that cause the gasses to ignite.

I no longer use plastic dryer vent from the fan to the forge after having 3 of them catch fire during a backfire, melting the plastic and setting it on fire. As the smoke ignites and burns, it can be a traveling fire as the smoke burns in the air line, a soft whoomp, or an ear splitting bang.

Do not let anyone tell your that blacksmithing can not be exciting !!