Secondary burn system ?

[Riri]

Hello,

I'm not even a beginner for the moment, but i'm thinking of building a small coal and/or wood forge (gas is expensive) and i'm wondering if there is a way to have a kind of secondary burn of the smoke in a forge, a little bit like in a wood stove. Or at least a way to efficiently reduce the smoke.

The aim is to avoid problems with the neighboors.

Thanks

[Daswulf]

Coal and wood will smoke more, coke and charcoal (use the lump charcoal not the briquetts to forge with) smoke less. 

Think of a bbq charcoal grill, they dont smoke much and when they do it is usually the food or juices from it burning off. 

[Frosty]

I think Bealer described and drew some pics of systems to control smoke in, "The Art Of Blacksmithing," I've never tried any of the more elaborate methods and some are maybe some unlikely. Good fire management works to a reasonable degree.

Frosty The Lucky.

[Riri]

Thanks For the advice !

[Purple Bullet]

Just a few details on what (at least I think) are "good fire management" skills: If you want to minimize smoke, always have a visible flame. I start my coal fire with a handful of charcoal and a mapp torch. I use a hand crank blower and I start slow and slowly push heaped up coal from the sides in amounts that will not smother the flame and cranking briskly. I find that I can get a really good fire going without hardly any smoke. This usually results initially in an oxidizing fire. Usually, you want a reducing fire, so then you slow down the blower and build up over the fire using your water can to wet down the sides. This creates a shell of coke in which your fire burns and most of the oxygen is consumed. As the coke is consumed you have to pack in the sides to feed the fire. This will cause cracks in your coke wall where the fire tries to break through so you repeat the process, coal, water, pack.

I am by no means an accomplished smith and some of the others on this forum may have better explanations, but this has worked for me.  (Mostly for welding cable.) What I find strange is that I hardly ever see the watering can being used in videos and I use mine a lot to control the fire and conserve coal. If you live where coal is cheap and readily available I guess you develop different ways of working.

[George N. M.]

Welcome aboard from 7500' in SE Wyoming.  Glad to have you.

If you put your general location in your profile we can give you better answers and suggestions.  A surprising number are geography dependent.  This is a world wide forum and we don't know if you are next door to one of use or are in Lapland, Tanzania, or Tierra del Fuego.

Smoke is pretty much unbrned combustion products.  If you have a hot enough fire there is little smoke.  Charcoal and coke are less smoky fuels than wood and coal because some of the volitiles and smoke producing materials have already been driven off in the processes to convert them from wood and coal to charcoal and coke.

Also, charcoal and coke have less combustion odor than wood and coal if that is a concern for you and your neighbors.

Depending on where you live propane may be comparable in price per BTU to solid fuels.  If you are in the USA buying propane at a bulk dealer is usually significantly cheaper than getting exchange bottles at the super market, convenience store, etc..

"By hammer and hand all arts do stand."

[Riri]

Thank you all for your answers. You are all agree about the importance of the fire management.

@Frosty, I will have a look to "the art of blacksmithing" book for such systems.

@George, thank you. I'm from France, North West, Brittany. I'm going to edit my profile.

I'm thinking to start with solid fuel because it seems that here in France, nowadays, it's cheaper and also more simple to begin blacksmith, according to some french smith on youtube. But as I said, i'm not even a beginnner for the moment so I have to see by myself.

And at first sight, i am more attracted to the old blacksmith techniques. There is something primitive in it that appeal me. A man and a fire..!

[JHCC]

We had a good discussion a couple of months ago about the Buffalo Model 660 forge, which included a intake to pull smoke from the fire and rechannel it through the blower. I don't know if you'd find anything similar in France, but it might provide some inspiration if you build something of your own.

 

[Riri]

Thank you JHCC, this is very interesting ! Exactly what I was looking for.

At first sight the principle seems simple, i'm going to think about a DIY system like that because it seems impossible to find that forge in France. I just typed it in google and there is no results in french.

The steel plate version must be something possible to copy for a hobbyist. With a lot of work of course.

Perhaps it's even possible to adapt that kind of blower on a forge made of refractory stones.

On another subject you wrote "That portable model on the right is an abomination" talking about the 666 (666... ), what did you mean ?! Was it just for the joke ?

[Frosty]

When I burn coal I start the fire with a strip of corrugated cardboard 1 1/2" - 2", 35-50mm wide rolled into a coil placed over the blast grate I let it spring open a little and pile coal around it to hold it. I partially cover it with pieces of coal and cover the outside of the crater shaped mound with wet fines. Air can move freely through the mound out the crater but the fines prevent much from exiting the sides. I drop a wooden match in a gap in the coil and apply a gentle blast till the coil is burning well, then I cover it with peanut sized pieces of coal and increase blast as everything gets burning. This leaves an open flame in the center of the mound and the smoke is channeled to the flame.

It isn't perfect and takes patience but it's a technique that let me burn coal in a trailer court with the neighbor about 30' away. I sharpened lots of knives and did minor repairs for my neighbors and never got complaints that were taken seriously. I usually ended up with an audience.

Recycling smoke through the blower to the fire is sort of the same thing, it's using the burning fire to completely burn the volatiles that make up smoke. Making a hood that did this wouldn't be too difficult but you might have to make several before you got one that worked well enough.

Frosty The Lucky.