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How To: Make bellows with primitive tools

Posted by on 2012/04/16

This is meant to be an addendum to Campsite Crafting 05: The Bloomery

I’m going to need some help with this.  I found an out of print book called “The Navajo and Pueblo Silversmiths” which describes the ‘primitive’ bellows.

Here’s the passage that may be relevant:

“…. The three uprights and the ribs are of oak, from a tree felled on the Zuni mountains twenty miles east of the pueblo. Thongs draw in the hide between the ribs, forming three compartments on each side of the center upright.  On this bellows, the air spout, made of rawhide, is mounted on the center upright, and there is one intake on each end of the leather bag.  An Iron Bar passes through holes drilled in the upper end of the wooden supports and keeps the air bags in line.  The top of one of these uprights serves as a handle by which the bellows is drawn in and out.  The other one of the two uprights is fastened in a stationary position.”

and

“… in the Navajo bellows, if one may judge from a photograph of one.  In the Navajo bellows, the intake is at the opposite end from the outlet, and on a line with it, while in Keneshde’s bellows, the intakes are in a transverse position.  There is an advantage in Keneshde’s construction in that he has made a double bellows, which may be worked by pulling only one handle, while the other hand is left free for manipulating the crucible…  The navajo smith built a double bellows by placing the two air chambers side by side, instead of one adjoining the other in a single construction.  By pulling and pushing the two handles of the bellows alternately, a steady draft issued from a bifurcated spout.”  – The Navajo And Pueblo Silversmiths; John Adair

 

Actually making bellows is kind of a complicated task, but if we want to melt metal, we need them like the red warrior needs food, badly.

Unfortunately, without advanced tools, or precise measuring equipment, we have to work with what we can fabricate in the wild at our current level of technology.

We have a knife, probably a few knives at this point, made of stone, flint, and bone.  We have clay.  We have hide. We have glue, and we have bone.

The basic function of a single bellows is thus; a wooden or metal frame that is encased in or encasing an ‘air bag’ with an intake and a spout. When the bellows are pulled open, by a pair of handles joined at a fulcrum, the intake ‘valve’ or flap opens filling the bag with air, like your lungs when you inhale.  Then during the reverse action, as the bag is compressed, the intake flap closes and forces the air out through the spout, so it can be directed into the Tuyere, into the furnace, allowing the coals to burn hotter and hopefully reach the melting point of our metal.

Making this device is simpler in theory than in execution.

The theory is that we’d make a pair of A shaped frames out of a soft wood, an air bladder out of rawhide, and a nozzle out of some fire-clay. Lash the construct together with cordage, and seal the bladder with hide glue.

The issues that need to be resolved:

Making our intake flap requires some delicate leatherworking, as it must seal tight when the bag is compressed, so that the air is forced out of the spout.

One suggestion was why make a separate intake valve – while it may work to make a single port in the air bladder and use it for both inhalation and exhalation, each time the bellows is stroked it would have to be removed from the tuyere and reinserted, a viciously inefficient practice.  Once we can start making simple metal tools, we can update our bellows with a more effective Double Bellows system, and eventually build machine bellows, but until then, we’ll try to come up with other ways to extract that iron ore.

I’m also looking for schematics for a Roman Bellows, if anyone comes across them drop me a line at SurviveWhatever@gmail.com.

Using our primitive tools, we’ll be destroying a lot of materials in the trial & error attempts to actually construct the final device.

If anyone would like to draw up some schematics, I’d appreciate it, I have no hand for art.

As I experiment with this process, I’ll update this entry.

Edit: Thanks Sam

I’m looking into bag bellows, and hopefully I’ll be able to find a simple tutorial I can hijack and incorporate.

If we can make a bag bellows work with buckskin that might be a primitive enough solution to work into the technology ladder.

 

One Response to How To: Make bellows with primitive tools

  1. Sam

    Bag bellows…Easier to make by far, however any way to get more oxygen into a fire will work. I have forged with a fan…like a legit foldy up, lacy, girl fan (ok it wasn’t lacy)(Yes it sucked and didn’t work very well)(that may sound chauvinistic, sorry). I have seen people forge using a buddy and a long hollow reed. Several scouring rushes opened up and the bits that stop air flowing removed would work, you’d probably need about 10 of them at a time for it to be useful. A bunch of cat tail stalks with the pith removed could also work…keep in mind they are temporary and will burn up as you go so have more than you think you’ll need and then double it. You won’t be moving metal very efficiently with rocks.

    Bag bellows work well but it’s helpful to have a buddy. You may say “I don’t have any buddies, I am self sufficient.” I say sweet, me and my buddies are looting your corpse. They don’t require any specialized tools or metal to make and they were used for a couple thousand years. you can use troughs in the ground covered with wood and more earth instead of pipes (again the traditional method) and make the bags and valves out of skins and bone or wind breakers and sticks. Use a plastic bag or tarp like the video below. Use your brain.

    http://www.youtube.com/watch?v=iyMBq0xVOd8 (after that bit on friends this guy is doin it by himself and kickin butt)

    I couldn’t find the link I wanted, don’t blow into the bag, instead use two sticks to make opening you can close with one hand at the mouth of the bag/large opening of the hide. open it, lift the bag, shut it, push the bag down. Lather, rinse, repeat. Two bags working in tandem (one guy with a bag in each hand) can produce a constant and effective flow of air.

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