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blackravenforge

bellows help

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I have started to get into a more "primitive" kind of smithing. I am using hard wood lump charcoal and i have a small bellows, but i was wondering about making a japaneese stile bellows. i was wondering if anyone had any experience with them, or could give me links on this site or others telling me how to build one. btw sorry about any spelling mistakes. i just woak up and can't really focus very well rite now. thanks.

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To experiment with box bellows before you invest time and energy in making them from wood, cardboard boxes work dandy. A paper bag and piece of pipe will make good enough bellows for a field expedient.

Frosty the Lucky.

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I found exactly the opposite than Doc. With my double lunged western style I could blow a forge to welding heat using my pinkie *and* by filling the top chamber it would keep pushing air out while I went to change tongs or take a swig of tea.

The chinese box bellows I used as helper at a Quad-State demo took constant attention, you stopped---it stopped and took more force to use.

HOWEVER my western double lunged took up most of the bed of my pickup and the chinese box bellows could fit behind the seat of my pickup and be moved by one person.

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An animal skin with some sticks that you open and pinch with your hand is another ancient (and still used) form of bellows. The pipe would be fastened into a leg hole, and your hand is used to open and pinch for the valve.

You can quickly whip one up out of a heavy plastic bag, like a trash bag and a piece of pipe. Of course the service life would be rather short for a plastic bag, especially if it gets too hot.

Phil

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I just built a box bellows but I haven't had a chance to get it hooked up and try it with a fire. What I can see already is that it's capable of huge volumes of air which makes sense when you consider the smelting the Japanese smiths have done. I watched a Youtube video series where the smith started with sandy soil and finished with a samurai sword. Thomas is correct that they require more force and focus to use. He's also correct that they are quite compact. I'm looking forward to trying it out because I suspect it will reduce the cycling time to heat the steel owing to the greater draft. I'm also curious to see how that affects my coal consumption. Right now I'm trying to figure out how to mount them on a mobile forge solidly enough to make the strokes efficient.

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I used a double lung my self for years the advantage is when you stop pumping the second chamber still will send air. if you have a small one that make up an other small one and set them up to work opposition raising the arm activates one and lower the arm activates the other. I have seen wood carving of this set up in Maximilian's armory. http://books.google.com/books?id=F-CHHCk2ybsC&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false

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I thought I'd follow up on my earlier post since I got to try out my box bellows over the weekend. It was a learning experience for several reasons.

First off, this thing pushes a HUGE volume of air. In fact, it's actually possible to blow so hard you put out the starting fire! This isn't really a big problem since sedate cycling is much less strenuous. My "cylinder" is 12"x12" with a 36" stroke. That's 3 cubic feet of air for every stroke!

I had three hammer heads in the fire and all three would get red hot within minutes without tiring me out. In fact, I found the heat cycling time so reduced it reminded me of a propane forge. The fire was more than hot enough to weld. I accidentally burnt a bit of steel because it came to heat so quickly I didn't expect it.

I have a 2" water pipe leading into my fire pot with a cap on it. The cap has a 3/4" hole in the center, the whole thing is about 2" above the bottom of the pot. I think I got the idea from a post Phil wrote a while back. The clinker that formed was a perfect doughnut shape resting around the base of the tuyere pipe . I couldn't be happier with how well the fire maintained heat, or how quickly I can re-heat a forging. Plus it's really nice not to have clinkers clogging up the works while working.

If I were to make changes, I'd put my fire pot closer to the bellows handle so I can better see the fire whilst cycling the piston.
I would also consider making a fire pot that's longer with several tuyere's like the Japanese forges -I'd probably make it with movable partitions to use only one tuyere as wanted.
The reduction in back pressure on the bellows would make it easier to cycle, plus it'd be handy to heat long bars on the rare occasion that's necessary.

So far this is the best bellows I've made. I can see that a crank bellows / blower is better in just about every way. I could never find one that was affordable so I went the home made route. Good luck with your project!

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Thanks for the follow-up on your box bellows. My son and I are building a forge, and we're trying to figure out the forced air supply.
Your post has been very helpful!

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In case you are interested, I have been photographing the process of building a standard bellows and side-blast forge at:
http://www.facebook....35399321&type=1


That's awesome! I bookmarked your FB page.

That bellows might be more than we can take on at the moment, but you've got me thinking. For now I think my son and I are going to build a natural charcoal forge with a "v-trough" ( kind of like the "Lively" style) with the air coming from the bottom.

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I found exactly the opposite than Doc. With my double lunged western style I could blow a forge to welding heat using my pinkie *and* by filling the top chamber it would keep pushing air out while I went to change tongs or take a swig of tea.

The chinese box bellows I used as helper at a Quad-State demo took constant attention, you stopped---it stopped and took more force to use.

HOWEVER my western double lunged took up most of the bed of my pickup and the chinese box bellows could fit behind the seat of my pickup and be moved by one person.


It was a Japanese style bellows Thomas....though one can make the point that the difference is mute in the end.
That was a good time at Quad-State that year...or at least I had fun.
I have forged with the personal box style as well as the early Viking style..both are smaller in volume that the American version often turned into coffee tables these days. I think what you need to decide is what you are trying to accomplish with your bellows and go from there. If you are after a certain style or time period then you need that particular thing.
All of them make air and all are useful and I am not sure which one my kids prefer.

I have seen Japanese smiths who have an electric blower tucked into the end of the box bellows....for when tourists are not around.

Ric

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here are mine.. i would probably make them smaller is i build another one mine are 4 foot long but i can use shorter strokes if i want, very fun build and simple

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Ric; I had fun at that Demo and I must say you dealt with the floating eyeball in the quench tank very well...

I originally started out with an electric blower and later switched to a hand cranked blower as I decided I liked it better. Later still I found that I preferred my double lunged bellows to the hand cranked one---save that it was a pain to travel with (and got left when I made my last move as it was 20 years old and needing to be replaced rather than patched all the time...) As I do historical demos, I have a Y1K set up with two single action bellows with no check valves---it is my least favorite method because it really requires a helper to do substantial work with it and is a pain to do *any* work single handed.

HOWEVER I can say that a "good" example of an air mover is LIGHT YEARS BETTER than a bad example of the same sort of thing---I could pump my double lunged bellows with my pinkie, a friend messed up his rotator cuff using a double lunged bellows *not* set up properly. My hand crank blower was easy to spin and would make 3 full turns after letting go. Other small rivet forge blowers or large fancy blowers took considerable force and constant cranking, etc. So if you don't like how a method is working for you it may be that the specific system is at fault rather than the method!

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