One of the invisible tools of the Bronze Age metalworker is protective gloves. It’s difficult to work with hot metal without some sort of protective hand gear. Even when using wooden tongs, it’s difficult to keep your hands away from the heat of the furnace. Handling heated stone or clay moulds is also difficult without gloves.
The most popular hand protection is to use commercial welding gloves. They do a good job and are fairly inexpensive. On the other hand when working with students, I have to regard them as being disposable. Someone will inevitably burn the leather, making the fingers stiff and difficult or impossible to work with.
When I was in Moscow for the Times and Epochs Festival, the bronze casters there had a nice alternative: felted wool mittens. They look like something that would have been used in the Bronze Age, do a great job of protecting hands from heat, and are repairable. When I got back to the US I wanted to make myself a pair.
Cardboard forms for the gloves and clean wool roving.
Making the mittens is a fairly straightforward process. Make a pattern out of some heavy cardboard by tracing your hand and adding a couple centimeters all the way around (the wool will shrink). You will need some wool. I bought some roving, wool that’s been cleaned and made ready for spinning, but you could even use wool straight from the sheep. Just make sure that the wool you use is not labeled as ‘superwash’. Superwash wool has been processed to prevent shrinkage. Great if you’re knitting socks, but useless for felting. I have small hands (another advantage, you can make these to fit!) so I used about 170 grams of wool. The only other supplies needed are hot water and a bar of soap. This is a messy process and takes awhile. You’ll need a clean work table in an area where you don’t have to worry about getting the table and the floor wet. Not to mention yourself. My thanks to the staff at StevenBe who let me use their felting room for the process
The wool is spread out and the pattern laid on top
Lay out the wool so there’s enough to fold over the edges and top. Make sure that the bottom stays open. Take off the pattern for the moment and wet the wool with hot water and scrub it with the soap. Get the soap all through the wool. This is going to be messy. Put the pattern back and fold the wool so it is completely covered, except for where your hand goes in. Now, pushing down on the wool scrub it around on the work table, keeping it wet and rubbing in the soap, flipping it over and doing the other side.
Lots of soap, hot water, and elbow grease go into the felting process.
When the first layer is completely wet and starting to hold together, add more wool wrapping it 90 degrees from the first layer. If the first layer was from the top to the bottom, the next layer should be side to side. Keep soaping it up, adding hot water and scrubbing it around. At some point the cardboard is going to start disintegrating, so put your hand in there and scrub from the inside. By now you’re losing the will to live, but keep going.
Felting works because wool has scales, almost like tiny hooks. The action of heat and agitation causes these scales to get tangled and bind to each other. This is why wool sweaters shrink when they get put into a hot washing machine or a dryer.
Keep adding layers to the wool until it gets almost as thick as you want it. The wool will compress and get a little thicker when it dries. Once it’s the size and thickness you want, rinse out the soap and let it dry. Drying takes a long time depending on the weather. You can put it in a dryer, but be careful that it doesn’t shrink. A dryer can reduce the size considerably and compress the wool to the point of being dense. If the mitten shrinks too much you can wet it down again and stretch it out some more. You can also put something inside the mitten to keep it from getting too small.
The glove is done. It needs to be dried now.
Once it’s done, you can twist it or pound it to get it a little more flexible. There’s nothing to say that you can’t also decorate it
I was invited to cast bronze at an event in Germany, but the catch was that I needed to dress in period costume. The skirt and tunic were easy enough, but I knew that the people there would look at my Iron Age shoes and comment on how anachronistic they were. I know, because it’s happened in the past. There are few Bronze Age shoes that have been preserved, and the most famous were the ones worn by Otzi, the Ice Man whose body was recovered in the Alps in 1991. There are a few websites describing how to make them, including one with a video,
Following the instructions onthis website,I cut out a pair of soles from the same leather I used for the Iron Age shoes, and punched holes around the perimeter. I didn’t have leather lacing, so I stitched them with multiple strands of sinew. Then I got some jute cord. This is made from the inner bark of the lime, or basswood tree (tillia sp). It is essentially the same as the cord used for Otzi’s shoes. I cut several lengths and started plaiting and knotting.
Lacing the Bronze Age shoe sole
I quickly realised that it wasn’t going well. I couldn’t tie the knots while wearing the shoes, so I made a sort of shoe last out of socks. I just wasn’t enjoying the project and it was looking a mess. I just wasn’t getting the measurements right and the shoe was too large.
Putting the cords on the Otzi style shoe.
I just wasn’t producing what I wanted, so it went on the back burner. When it was about a month out from the event, I nagged myself into getting the shoes done. The problem was that I wasn’t happy with how they were turning out. It would be easier if I was making them for someone else, where I could tie the knots while they wore the shoes. It was then that I convinced myself that I didn’t need to slavishly copy this particular shoe. The materials were proper for period, I just needed to find a way to make them so I was happy while using a technique that would be consistent with the Bronze Age. I decided to make a netted upper rather than one that was plaited and knotted. I started over, this time using a single length of cord. I measured off a length that was 5 times the circumference of the sole (note, this finished about half the shoe. On the second one I measured 9 times the circumference and that worked out perfectly).
I wove the cord in and out of the sinew, skipping every other stitch and leaving a small loop at the top near the edge of the sole.
Weaving the cord through the sinew to make the upper part of the shoe
Then continuing around, I brought a loop through the loop next to the sole and then threaded the cord through that to make a knot. It was easily adjustable.
Bringing the cord through the loop
The loop in loop
Pulling the cord through the upper loop
Pulling the cord through the upper loop, another vieww
Pulling the knot tight
I made the first round fairly tight so that it would pull the sole up around my foot. I did the same for the second round.
Fitting the shoe to my foot. At this point the netting is fairly tight.
On the third round I made the loops larger because I wanted a netted effect. If I wanted, could continue making the loops smaller that would result in a denser fabric. At this point it was easy to work on the shoe while wearing it.
Making the loops larger to make a more open netting.
After a couple more rounds I started making the loops even larger. I brought the cord around the front of my ankle, looping the cord between it and the loops closer to my toes.
The netting continues with wider loops
The netting is finished and fits around the front of my ankle.
By this time I was essentially done. It took me about three hours for both shoes, working at a relaxed pace. I had a fair amount of cord left over, so I wound that around the top cord of the shoe to reinforce the opening and to give it a bit more of a finished look.
The finished shoes
I made this pair fairly tight because I figure that both the leather and cord will stretch over time. Still, they are easy to slip on and off, and are comfortable for walking. I could make some leather uppers to go over the netting. Otzi’s shoes had that, although there is debate as to whether the leather was on top of, or under the cording. A project for the future is to learn nålebinding to make some socks.
Bag bellows might be the oldest form of bellows used. We don’t know for certain because they are made entirely of organic materials, and so none survive in the archaeological record. Because they have the advantage of being portable, lightweight, and easy to make, this type of bellows are still in use for iron forging in parts of Africa and South Asia. When you make a pair, you can be as “authentic” as you want, using only wood and leather, or you can use more readily scrounged materials like vacuum cleaner hoses and pleather. There is a remarkable video of Kenyan metalsmiths using bellows made of cement bags here.
In addition to this tutorial, check out the Bellows Forum page where there are variations of bellows designs and some interesting variations.
Traditionally bag bellows are made of pliable leather and the usual description is that a single bellow is made from one goatskin. The bellows I describe here are made with upholstery fabric. At the time I made them, leather was too much for my budget. After they were sewn I gave them a good coating of linseed oil that made them both waterproof and airtight. I find it ironic that in the Bronze Age leather would have been readily available, but hand-woven fabric would have been exorbitant. So, these are my ostentatious display of wealth bellows.
How big the bellows you make will depend on what’s comfortable for you. I’ve used very large bellows and ones so small you’d think that they’d never produce enough air to get the job done, but they did remarkably well. What is important is that the size works for you. You’ll be sitting on the ground, or close to the ground (I like a log or a short tree stump with a bit of padding). Sit down on the floor and raise your arm with your elbows bent so that they are lifted a little over waist high. Try not to move with your shoulders. You’ll be pumping your arms up and down for hours, so it’s good to find a height that works for you so that you don’t wear your arms out. Measure that height or get a good idea of how high that is. Then you’ll want to add a few more inches because you want to have the bellows rest on the ground. If you lift them too high, the sides will collapse and you won’t be able to trap the air in them. You also want to add another few inches to wrap around the handles.
Besides the leather (or whatever material you choose) the other supplies you’ll need are heavy waxed thread or sinew, leather or sail needles (depending on the type of material you’re sewing). The handles are made of two straight branches about 3-4 cm (1-1 ½ inches) in diameter, or four boards 3 by .5 cm (1 by ¼ inch) the length will depend on how wide the top of your bellows are. If you use branches, they’ll have to be split lengthwise so that they have a semi-circular cross section. My bellows are about 16 inches wide.
Using your own measurements, adapt the pattern below, adding about 3 cm/1 inch for the seams around the edges, and enough at the top to wrap around the handles. You’ll also need some scrap to make loops for your fingers. The loops are more important than you realise. Getting them right will mean the difference between being able to work for hours, and giving up because you keep getting blisters or losing your grip.
The basic pattern for cutting out a pair of bag bellows.
Another useful detail is to sew a small triangle in the front of the bellows, just below the handles. Holger Lonze taught me this trick. It makes it much easier to open the bellows wider and get more air in.
The small triangle set into the front of the bellows. Note that I put in a couple stitches so that when the bellows close, the triangle folds inwards.
The other detail is the part at the bottom that sticks out. This is where the tuyere will fit. The size you make that will depend on the tuyere you make, and also how much air you want to push through to the fire. If it’s too narrow, you’ll be expending a lot of energy pushing air through a small space. Too large and you’ll be pumping furiously to get the volume of air through the tuyere. Mine is about 10 cm (4 inches) and tapers a little so I can fit different tuyeres to it in case I ever want to change it.
The other supply you’ll need is rawhide. Leather strips can work, but they aren’t as durable or tight as rawhide. The best source for rawhide I’ve found is the pet shop. Buy a rawhide chew bone for a dog and soak it in a bucket of water overnight. The rawhide will soften and you can untie the ends and unroll a nice sheet of rawhide. I cut it in a spiral so I have good, long pieces. While it’s wet, you can wrap it and tie it easily. Once it’s dry it shrinks to a hard, tight fit.
A close-up of where I tied the opening of the bellows to the tuyere
Cut out the leather or material and then stitch it with the outsides together so that when you turn it inside out, the raw edges will be on the inside. Don’t sew it all the way to the top. You want that extra selvedge to wrap around the handles. Make sure you fit the triangle in the front below the bottom edge of where the handles will be.
The next step was the hardest for me. It’s a bit of a pain. You need to wrap the upper selvedge of the bellows around the sticks and sew them tightly into place. If you’re using half-round branches, make sure the flat sides are on the inside so they meet and make a tight fit. Sew these in tight along the bottom of the sticks. It’s annoying if they wobble around.
The finished bag bellows. Note that the handle is towards the rear of the bellows.
Turn the bellows right side out and admire your work.
If you used branches, you might not need loops for your fingers. Try pumping them a bit and see if you can open and close them easily without them slipping out of your hands. The action is to open them while the top of the bellows is close to the ground, Lift them, close them when they are as high as you want to lift them, close the bellows and then push down. If you lose your grip, you might want to put loops on them. They are simple, just strips of the same material that your bellows are made from. Sew them so your hand will be about 1/3 to 1/4 of the way from the back. When the bellows open, the little triangle in front will allow the bellows to open in a “V” shape and allow you to trap more air. Having the loops toward the back means that you don’t have to open your hands as wide. Since I work with kids a lot, this was a consideration when I designed them. Also, I have small hands.
This shows the handle at the top of the bellows and how to hold the bellows open while using them
The loops should accommodate four fingers on one side and your thumb on the other. The handles will stretch over time, so I periodically have to stitch them again to tighten them up.
There now, try them out. If you feel any air leaks in the seams you can seal them with linseed oil. If you made your bellows from fabric, the easiest way to coat them is to hang them on a clothes line outside and slather the oil on with a paintbrush. It takes a long time to dry and smells pretty strong. It’s definitely something to be done outdoors. Keep in mind that it might take a day or two for the linseed oil to dry.
Now in order to work, you’ll need at least a short tuyere. If you’re not fussed, some steel tubing from a vacuum cleaner works fine. If you want a more Bronze Age look, you can make them from wood. I took a short branch and drilled a hole in it using a 2 cm flat bit (1 ½” spade bit in the US). The branches are about 1 cm or ½” wider than the bit. If you don’t have a bit or don’t want to use power tools, take a branch of the right thickness (about 4 cm or 3”) and split it in half. Carve out the centre and fit them back together using glue and rawhide.
Fit one end of your tuyere into the opening at the bottom of your bellows (you didn’t sew that shut, right?). Now take the wet, sloppy rawhide and wrap it tightly around the part of the bellows covering the tuyere. If your tuyere is made of split branches, keep wrapping so that it holds the halves of the branch together. Depending on the weather and humidity, it might take several hours for the rawhide to dry.
Once everything is dry, try them out. They’ll be a bit stiff at first and will need to be broken in. It takes a bit of practice to get the Open-Lift-Close-Push rhythm going, especially if you alternate hands. Once you get into it, it gets easier. Think of a cat kneading its paws.
Another tip is to get some thin willow twigs, about the size used for making baskets. Make them into hoops that will fit inside the bottom of your bellows. It will help keep them open, especially if you have a tendency to lift them too high.
Next you’ll be wanting a “Y” shaped tuyere to connect the bellows together.
Bellows are a bit of a mystery. We know they had to have existed in the Bronze Age, but the only physical evidence we have consists of fragments of tuyeres. An Egyptian painting from the Tomb of Rekhmire, from 1450 BC shows a man using pot bellows that are operated by hands and feet. There are also Chinese documents depicting the use of box bellows. But bellows, after blowpipes, are likely to be one of the earliest forms of delivering air to the furnace. Unfortunately they are also constructed of ephemeral materials.
Scene from the Tomb of Rekhmire. The man on the right is operating a set of pot bellows. The valve is opened when he lifts both his foot and pulls on the cord attached to the top of the bellows. The air is pushed out of the bellows when he steps down. These require a lot of coordination.
Until a set of bellows is uncovered preserved in a bog somewhere a lot is left to the imagination. How big or small could they be? How can the valves be altered to be more efficient? How heavy should the leather be? Should sturdiness trump suppleness? How are all the parts held together and made airtight? Bellows are one of the most essential pieces of equipment that we have for casting bronze and yet very little information is available about their origins, and we rely on information for their use and construction from the community of experimental archaeologists and reenactment groups.
Over the years I’ve seen many different shapes and sizes of bellows and always thought that a forum where bellows design and use could be discussed would be invaluable for people to share ideas and experiences.
I would like to invite others to share photos of the bellows they’ve made on this site. This could be a welcome forum for discussing the pros and cons of different designs, what worked, what didn’t. Of course any news of archaeological bellows or tuyeres discovered would add to the fun.
Note the round bottom. a good way to keep the bellows from deflating if they are pulled up too high.
The new bellows, ready to use
Close-up of the new bellows showing how the valve and handles were assembled
An earlier set of bellows by Morgan van Es. These had smaller bags and took more work to deliver enough air to the furnace.
Note the depression along the top of the tuyere. The tuyere is made from wood in which a deep groove was cut. Then the tuyere was covered in leather. Much less labour intensive and it delivers the air very well.
A close-up of the tuyere that Morgan made for the bellows
Pump Bellows
Matthias’ bellows: I saw these at the 2018 Bronze Casting Festival at the Bronzezeitehof in Germany. The handles can be adjusted at an angle, and they have other nice features.
Note that a small nail and a bit of string can give you more control and make it easier to close the bellows when the valve is on top.
These bellows have the leathering on the outside. This decreases the possibility of air leaks, but also limits the height that the bellows can be drawn. That said, they did deliver a lot of air with little effort.
I would welcome others to send in photos of their bellows, and not just bag bellows, any bellows that could be considered to fit in with what we know or can surmise from archaeology would be interesting for this forum.
