blowers

[yesteryearforge]

what kind of blower do you use on your coal/coke/charcoal forge
electric paddle type
squirrel cage
hand crank
bellows
what do you feel is the advantage of the type that you prefer over the other types.

[ThomasPowers]

Yes

I've used all of them. I started with an electric blower (both types) and then moved on to a *good* hand crank---it's large, easy to crank and the handle makes 3 full revolutions when I let go of it. Some small or hard to crank ones make the job too much like work.

I found I used less fuel and burnt up a lot less metal when I was responsible for the blast and that I would automatically tweak the fire to get exactly what I wanted for the job at hand.

Then for historical demos I built a double lunged bellows and found that the steady blast and large air storage was even nicer. I have it rigged that I could pump it with a single finger and I've even welded up billets with it.

However I still prefer an electric blower if I have to do a lot of pattern welding.

Now I've used bad versions of all of these---electric blowers with no control, hand cranks that wore me out and even a bellows that took all you could give to pump it---did some serious wear damage on the smith that had to use it as part of their job at the historical smithy.

Thomas

[Ten Hammers]

I use a power blower daily in the shop. Squirrel cage scrapped furnace fan. Works great. Pic of the airgate I use in the Gallery. I have several crank blowers and use one on the trailer forge. I have absolute control with the power blower in the shop. Blower runs constant and I use the airgate to vary the blast. The trailer forge has a Canedy Otto freestanding blower.

[drason69]

my rivet forge had a lever to power the 'paddle fin blower' it came with. but since it was pretty broken up when i got it from the scrap yard, i replaced the lever and gear section with the back geared end of an old kids bicycle. a leather belt is the connection between the two. an old disk plow blade and a section of steel pipe connect the bike parts to the forge. after removing the seat, i welded the two together. the tire was removed from the rim and a few holes and staples complete the leather belting (about 3/4 inch wide)
i just grab the peddle and crank away.
the next forge (2x2.5 foot cast iron pan) will be powered the same way, but with a 10 speed or mt bike as the gears and crank section.
i built a bellows, but seem to have made some mistakes in the air box section (part that opens to blow air and closes to keep from sucking in the fire) i need advice on that i think :)

[HeavyHammer]

I started out using a old pair of worn out fireplace bellows..which worked so-so for the tiny charcoal forge i was using. After i had pretty much destroyed them ,from such heavy use, i moved on to a large leaf blower with a variable speed motor. Worked good for about a week. Then it decided to go screwy on me and would blow out all the coal in my firepot....which isnt real fun when you decide to try melting aluminum in your forge.... :shock: ...But then i got a beautifully restored Canedy Otto handcrank blower with a big ol' cast stand. I wouldnt change it for the world. I've used electric blowers and they are nice for getting things hot real fast....but I still prefer the feel and control you get with a handcrank.

[GobblerForge]

Yesteryear, good question. For demonstrating, I made a cart forge with a hand cranked blower mounted to the cart and a rivetters forge for the fire pot. For the shop, I build a great bellows from scratch. As others have said, I like the control of the fire. As Thomas likes with a crank blower, I can also get a break by fully pumping up the top chamber. This gives time for preparing tools for the task as the chamber drains to feed the fire. Then there is the romance of the fire and the nastalgia that we take part in. The rhythm of the pumps, the sound of the air coming out of the fire and the flexing of the material on the sides of the bellows can be intoxicating. With all of this, and you can quitly talk above it. My bellows always lived in the space above my hammer rack, in the rafter area. The handle hanging above my left shoulder, above head high, as I stand at the forge. I also made an extension for shorter "helpers". Watching the bellows and "helping" is a thrill for them as well. Lastly, with any hand operated unit, you will never burn something while you aren't at the forge and you will use a little less coal. Good enough? Brad

[Leah]

I have an electric squirrel cage blower on my shop forge and a hand cranked blower on my portable forge. I may burn a little more coal when I use the ecectric blower but it is nice to not have to stand there and crank it when I am starting a fire or when I have just cleaned out clinkers and I'm trying to get going again.

[woodtick]

I use a home built rivet type forge with a hair dryer for a blower and a dimmer switch to control air supply. Not much cost involved to set up. I don't forge steady, but I do use it between 1 to 3 afternoons a week and so far it has been going for three years.

[HWooldridge]

From the standpoint of blower design, I have some real specific preferences on this subject.

Moving air has both pressure and velocity (cfm). For example, an air compressor will easily build enough pressure to blow fuel out of a firepot but the amount of oxygen moving thru the fire will be neglible. Try hooking up a compressor to a firepot - even at a low regulated pressure, you'll be hard pressed to get a good fire.

Squirrel cage blowers have a lot of small blades and are designed primarily to move air thru HVAC systems, so the CFM ratings are high but the static pressures are low. The reason for this is that there are few restrictions in properly made ductwork, but you do want a lot of air velocity so the hot/cold air makes it out of the vents and into the dwelling.

On the other hand, a traditional mechanical blower is made in a centrifugal design, which means it has a few large paddle blades - usually six or eight. This type of blower is intended to push air with some pressure but at a lower overall CFM rating. A blacksmith's coal/coke/charcoal fire requires enough oxygen to get hot but it also needs enough pressure to push the air thru the fire. This is why a bellows or mechanical blower works better than an electric squirrel cage - the former both deliver sufficient CFM to provide plenty of oxygen and enough pressure to make it thru a mass of burning fuel. This is really noticeable when forge welding, as only a breath of air is required to reach final temperature but it has to make it all the way.

The squirrel cage fan will make a nice roaring fire but you will experience more oxidation and hollow fires because there is just too much air moving thru the fire. If you try to choke the fan, the static pressure begins to diminish to a point that only the bottom of the fire gets hot. To compound the problem, this problem gets worse when a clinker or other obstruction forms.

When I do demos for the public, I use a "Tiger 300", which is a good sized mechanical hand blower. I don't know the manufacturer's name but it's a Champion clone - easy to work all day long with a decent fire and minimal physical effort. IMHO, there is a reason that experienced smiths still prefer to use a great bellows or old hand blower and that is because they have no peer for the purpose of supplying air to a blacksmith's fire.

[Ed Thomas]

As always, Hollis has captured exactly the issue. So go back and read his post again. :mrgreen:

A good way to capitalize on what he said is to look for paddle vane blowers. Centaur Forge has a very nice one that is strong enough to handle at least two fire pots. It is expensive but is a lifetime blower.

Another way is to keep an eye out for REALLY junked hand crank or ancient electric blowers. Those will be pretty cheap. All you need is the housing and the paddle wheel. In every one I've seen, the paddle wheel slips onto the end of a shaft from a motor or manual drive. Find a motor with the right sized shaft that is long enough and a good speed. Right now I'm using an old washing machine motor. It is perfect for my forge. I used a succession of 220V free motors for awhile, but they were too slow. It seems to work better with a 1750 rpm.

The one in use now was SO crappy looking and trashed that I almost junked it. It was a throw-in when I bought a pair of blowers that almost worked. With just a little TLC and proper mounting, it is the best I've used so far. You will have to build a mount for the motor, of course. And wire and switch it, but that isn't rocket science.

In my opinion, variable speed motors are a waste of money. I used one for quite awhile and found that I generally left the blower on some medium high setting and seldom changed it. It is much better to control air flow with a gate.

You can see by these pictures that all I had to do was make a motor mount (wood to dampen vibration), a simple angle iron mount for the paddle blower, and wire it. Oh, yeah... and clean & paint. My least favorite task. These shots were back when I had a 220V motor on it. As I said, the washing machine motor is much mo better.

You can also see by the tab cast in the bottom left, that this almost certainly started life as a manual blower.

[Ed Thomas]

Another hint for scroungers...

You can buy 3" flex pipe to go from the fire pot to the blower pictured above from Centaur Forge and others. It is several $$$ per foot.

Or you can dumpster dive wherever tractor trailer maintenance is done. The flex hose from the exhaust is 3" and usually stainless steel. I think you can buy it new, but I'm not sure what fun there is in that.

[HWooldridge]

Ed brings up a couple of good points I neglected to mention.

Stainless flex tubing is great but aluminum heater duct as found at Lowe's or Home Depot also works well. One downfall is that moisture which might accumulate in the bottom of any bends can combine with coal dust and eat a hole in the Al in short notice. Another problem is that this type of material is very soft and easy to poke a hole thru. Other than that, it conducts air just fine.

More good advice is Ed's note on speed control. It is far better with an electric blower to regulate with a damper or air dump than to mess with the speed. I learned this lesson when I was able to acquire a factory Buffalo forge with electric blower and rheostat. This forge (which I still use daily) came from an old Air Force surplus sale and had seen little or no use. I was fortunate to be able to see how the factory put one together - all the way from the stock rests to the half-hood. It was readily apparent that even on the lowest setting, the fan would outmuscle the fire in seconds. I burned up a lot of material until it finally dawned on me to leave the fan on and just adjust the air gate. The rheostat had specific "clicks" so I believe it was the factory's intent to operate in this fashion. For my single dedicated forge, I never use anything above the lowest speed setting but it is clear the blower will run multiple forges, so I'd bet lunch that Buffalo made it so the shop foreman could turn it on in the morning and have the workers control their fires as required.

[RBrown]

I have used a couple of electric blowers that i have riged up but use a hand crank now and perfer it. dont have to have wire any thing up and i have better control than with the electrics. iv got a champ 25 a mohawk (think 40) and a champion 400 i use the 25 all the time and the other 2 are spair.

[Leah]

While we are on the subject of blowers, answer a question for me. I have been told that, on a blower with a rheostat, you should let it come up to full speed on high then turn it down to the speed you need. Is there any truth to this and, if so, why?

[HWooldridge]

Leah,

A rheostat reduces voltage thru some sort of resistance circuitry. A straight AC motor without brushes needs to have close to full voltage to start. In other words, a 110v AC shaded pole motor with little basic load may start down to about 75 volts or thereabouts. I'm not talking about capacitor start motors or others under load - just direct drive fans like we would use on a forge. However, they will eventually reach a stall point where they won't turn and in reality, a squirrel cage AC motor is essentially either on or off, because the little blades on the blower cage don't catch much air when spinning slowly so you are back to my earlier comments in this thread about pushing oxygen thru a mass of fuel.

The advice you've heard to begin at full speed is so the fan will start, then you can turn it down to a certain degree, but the only thing you can have almost infinite control with is an AC/DC motor that has brushes. Most of the old electric blacksmith blowers are this latter type and will continue to rotate with very low voltage so there is always a breath of air going.

I believe it is best to install your electric blower with an on/off switch then put your air gate before the firepot. Turn the fan on full speed and control the air by choking the path (or the inlet - either works). In this way, you get the maximum amount of pressure the fan can deliver, but the volume is controlled so the fire doesn't get out of control.

[Leah]

Thanks, that explains some of the wierd things my blower does sometimes.

[Ed Thomas]

RBrown: If you prefer a handcrank blower then the electric blowers you rigged up were probably either rigged inadequately or were themselves inadequate. As Hollis and I pointed out, to get control of the air you need some good steady pressure, good volume and an air controlling gate. I've had both slide gates and butterfly gates. They are both fine, but you have to have good oomph and then regulate that.

For a very long time, I felt the same way you said, and even posted publicly that effect. I like the way you can come up to welding heat and gently feather in the last bit of air to get exactly the temp you want. A good manual blower is a treat to use. At one point I even installed a 'Y' connector with a gate so I could select either an electric blower or a manual blower depending on my mood. When I realized the manual blower was just collecting dust, I finally removed it. Now the manual blowers are used only for demos and group events needing several forges.

One problem is that while you are cranking, you can't forge. With an electric blower, you can have things heating while you are hammering. If you really want to become a professional as you said, this will start to become more important.

Another disadvantage of the manual blower is material size. When you move up to larger stock, you can spend a lot of energy and time cranking away trying to get up to heat. This is especially true if you use a power hammer. You can always get a bigger electric blower... you can't always go get a bigger arm.

[elkdoc]

I sucked it up and bought the med. sized blower from Kayne and Son's. I LOVE this little blower. Way more air than I'll ever need. I hooked it up with a straight shot to the side of my firepot with a sliding air gate inline to control air flow.

Works great!

[ThomasPowers]

A nice trick I learned from SOFA was to rig the electric blower with a foot switch---so it's only on when you are standing on it. Saves a lot of coal and stock as you are less like;ly to "forget" work in the fire. They also have a switch for on all the time for when you are needing a welding or other big fire. They also have an airgate to control the ammount of air to the fire when the blower is running.

Thomas

[Crunch]

Old thread, rank amateur newbie question:

I'm in the process of making my first firepot/forge (using a modified truck wheel rim for the firepot) and I need to rig up a blower.

I found a blower on ebay that looks interesting. I don't have the specs but by looking online I found an owner's manual for the furnace that it came out of, and the owner's manual says:

The Combustion Air Blower is a high head centrifugal blower.
It is designed to provide about 2" w.c. of suction at 30 CFM. ...
It is powered by a 120 volt motor which draws about 1.3 amps
at rated load.

The ebay listing is here.

Can anyone advise me on whether this blower might be suitable for an average-sized coal forge?

Thanks in advance for any advice.

[arkie]

OK, I'll admit I'm a real dummy when it comes to types electric motors, those in blowers particularly.  I'm a bit confused with the types of motors used on different types of fans and what type of controller to use.  I use a bathroom fan with an air gate and it works perfectly for me...has for years and cheap.  If I decided to go with a controller, and leave the gate wide open, what type of controller would work with that type of motor and fan, if any?  Ceiling fan controller? ( I ask, because I have a couple in my scrap box).

[ThomasPowers]

Universal motors have brushes, the others don't.

[arkie]

So, Thomas, I don't believe the bathroom fan has brushes, therefore a controller won't work, as eluded to by HWooldridge in a post above wherein he mentioned that the infinite control would be with an AC/DC motor WITH brushes....right?

[ThomasPowers]

AC/DC is a universal motor and so with brushes of some type