John Martin

Building A Bellows

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I've been doing some searches, and I want to build a bellows. I want to build a small one and slowly make bigger ones. How would I go about doing this? Could anyone point me in the right direction or point me to some instructions?

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What type? Single-action? Great (double-action)? Chinese box?

There are a few articles on building great bellows on the net, but IIRC they are mainly 3 foot by 5 foot. Think there is a blueprint or two also. Sugest you use heavy canvas or similar rather than leather; that stuff gets expensive!

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I have made a few double bellows. A couple for other smiths and one for myself. While there are many plans available in books and probably on the internet for making them, i have noticed that little attention is given to coordinating the size of the bellows to the size of the forge itself. While you may want to start out small for constructing your first set, remember it may not have enough volume for anything but a small fire. Without going into anal-retentive detail about why, I suggest you start with nothing smaller than a double bellows of 24" x 50".

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Check the IForgeIron.com > Blueprints.
They are how-to tutorials on building many tools, jogs, and projects.

BP0127 Bellows Construction
BP0141 Bellows Construction

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Some advise another blacksmith gave me that I have used: when applying the leather (or canvas,) do not divide it evenly between the top and bottom chamber. Use more on the top section, as much as a 1/3 to 2/3 ration. I have made smaller bellows work better than large bellows with this method.

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Hello Bros. Nice to see the young guns getting involved in the craft.
So you want to make a bellows? Great idea, that should be a lot of fun for you guys and if you take the time to do it right it should prove to be worth the while and serve you well.
I've also been toying with the idea of building one of these too. Mainly for historical reenactment demos, a year or two down the road from now.
I aquired an ancient colonial period anvil for this which is period correct and showing up with a Buffalo forge or Champion hand crank blower just wouldn't be kosher, so a correctly made bellows is required.
I've done a bit of research this way but not much yet, more when I'm serious about getting on with that job, but I can maybe offer a couple of pointers for you on your bellows build.
As Glenn pointed out check out those blueprints, a goldmine of info is there for you for free.
If you want a more detailed guide then I recomend the booklet titled "Making a blacksmith's bellows" which can be found in the Dixie Gunworks catalog for about 5 bucks. Their catalog also costs 5 bucks but I know this booklet is available elsewhere, on one of the blacksmith supply sights on the net maybe? I know I saw it out there somewhere (anybody?)
When involved in the build make sure to include some hardware cloth ( 1/4" wire mesh screen) over the holes to keep the creepy crawlies and mice out.
Leather can be expensive, a viable source may be an old leather sofa from the curbside showroom. Unfortunately the largest pieces, the back and sides, are usually vinyl, but this may be fine.
If you are near amish country, you can get leather cheap from them.
Gunlocke furniture company in Wayland New York has a scratch and dent store where they sell full size hides that are blemished but would work fine for a bellows, not cheap though, about $100 each.
Lastly, once you are the proud new owners of the magnificent new bellows that you have made yourselves I recomend mounting it to the cieling to save floor space and protect it from damage.
Good luck! :)Dan

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Do make sure you don't make it too small, somewhere before you get to 2' x 2' leaves it will be too inefficient to function worth pumping the handle.

Canvas makes nice bellows though you'll want to treat it with a borax solution to make it fire resistant. Putting it under the rafters is a fine old tradition to put it out of the way and help prevent fires.

If you have to put the bellows at or below the level of the firepot a safety trick is to build the tuyere so it's like a "P" trap. This prevents smoke, CO and other flamable coal gasses from flowing into the bellows and exploding when you give it a pump.

Frosty

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Check the IForgeIron.com > Blueprints.
They are how-to tutorials on building many tools, jogs, and projects.

BP0127 Bellows Construction
BP0141 Bellows Construction


I can't seem to find these :/

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If I remember right, the book The Village Blacksmith by Aldren A. Watson covers bellows making. Not at home now, but will check my copy this pm. As I remember, it goes into some detail.

bart

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there is a measured set of drawings in the the book "The Blacksmith" Ironworker & farrier by Aldren A Watson (paperback)ISBN 0-393-32057-x the bellows measures 36 x 67 you can scale it up or down
The other book is "How to make a Blacksmith Bellows" by Robert M. Heath no ISBN you can get both on Amazon
The bellows in the Heath book is 39 3/4 x 51 overall.
a lot of the plans I've seen on the internet they are using plywood for the inside panel . I've been looking a 5/4 decking at home depot and using my tablesaw and tongue and groove cutter instead of the spline joint that is shown in both books. I also found that Lowes carries 1/4 " popular that can be used for the valves...sure wish the weather would clear up so I could start on it

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I've made several bellows from plywood with good effect. It was pretty heavy plywood, 3/4"?, as I recall. I based my design on a commercial double lunged one from a museum and then scaled it so all the pieces would fit from 2 pieces of plywood.

Getting the frame set up and a good pumping pole set up so that it was easy to use was a big help---I could pump it to a welding heat just using my pinkie; while a fiend of mine ruined his shoulder having to use one that took massive amounts of force to pump at a "historical village" he worked at.

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I've made several bellows from plywood with good effect. It was pretty heavy plywood, 3/4"?, as I recall. I based my design on a commercial double lunged one from a museum and then scaled it so all the pieces would fit from 2 pieces of plywood.

Getting the frame set up and a good pumping pole set up so that it was easy to use was a big help---I could pump it to a welding heat just using my pinkie; while a fiend of mine ruined his shoulder having to use one that took massive amounts of force to pump at a "historical village" he worked at.

did you have any problem with nails on the edge of the plywood

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No, I stapled the leathers on and then covered the staples with pallet strapping held in place with screws. Was still going strong 20 years later when I gave it away for my move.

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No, I stapled the leathers on and then covered the staples with pallet strapping held in place with screws. Was still going strong 20 years later when I gave it away for my move.

thats good to know ...from what I've read the air pressure would tend to push the nails out of the plywood thanks

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ive made several bellows for my portable forges the latest is aprox 34x40 and it will produce enuf air to forge weld a tommahawk . probably the most inportant things to remember is make a good size valve hole in bottom and middle and make sire the leather or canvas seals well o coppied anothers ieda on my latest and had the leather overlap top and bottom and glued / tacked sides ant top /bottom. sealed it up niceley!

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I made a set by dividing a 4' x 8' sheet of 1/2" plywood into equal thirds. That makes the bellows 4' long by 2'-8" wide. I just proportioned the shape so it looked right and copied it to the other two pieces. I used sheet vinyl (pleather) from a craft store for the covering and I can attest that it's pretty expensive. I think I ended up spending about $70.00 on material. I stapled, glued, caulked, and duct taped all the joints. The truth is, that unless you've got a huge leak, the tuyere has less resistance than the seams so there's little getting wasted.

One thing I'd do differently are to start with multiple intake valves on the bottom and middle leaves. I started out with a 3" diameter hole in the middle and bottom leaves. That was WAY too much resistance. There doesn't seem to be a penalty to having lots of air flow, however smaller openings lead to valves that are easier to seal. Since my bellows were completely assembled I enlarged the opening to 7" square. I had quite a struggle getting the middle board valve in place.

The second thing is that I'd use smaller valves since the big 7" square flap gets hung up on the top board if I "short stroke". I've got a 1-1/2" pipe outlet from my bellows, At the time I thought doubling the diameter of the output pipe would suffice for the input valves, boy was I wrong. Reducing the cycling resistance is a tremendous boon.

The third thing is that I'd just make the bellows rectangular instead of tapered. The added work of tapering them doesn't do much but reduce air capacity and increase the perimeter you then have to seal. Plus the traditional shape is difficult to mount to a frame. I've got mine mounted to the stringers of my workbench which is also attached to my forge. The whole thing is too big but without a more compact bellows, I'm stuck with it.


I've looked into the box bellows but there are two things I don't think I'd like. #1 is the clacking and scraping noise they make. #2 is that they quit blowing immediately. I like having the top chamber flowing while I get ready to remove the metal. What I do like is that they're compact, durable, and capable of very controllable air flow. Plus you don't have to pretend to be an upholsterer like I did to make them!

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