# Forum Home Renovation Metalwork & Welding  Forge

## Marc

With my gate design came the need for better tools. 
i have a better vice and a better anvil and stand. 
The little nomadic farrier forge AKA 'rivet' forge will not do. Too much cranking and fire is too small.
So made some improvements. 
First was the firepot. Had some 6mm plate left over from another job and cut 4 trapezoid, 200x100x100 and welded them into a funnel.
Then cut a square out of 12mm x 100mm flat bar, cut 3 grooves in it and made the grill. 
Tac weld it to the bottom of the forge. Firepot done.  
If I have a deeper fire I need to pile up more coals so need a little edge to stop the coals from falling on the floor. Bending a round edge for it on the open jaws of the vice is quick and easy.
I usually do this with a ball peen hammer but the tool for this is a straight peen hammer. I only have cross peen hammers because they cost $120 a plop. What was my surprise when I found one for $20 at Bunnings! May not be fancy hand made one, but it works a treat.   
To bring this forge 100 years forward I need a source of air. Thought of motorising the fan but to do that I need to butcher the unit. So instead, I found a 4" gutter flange and some heavy duty epoxy glue and stuck it to the air intake. Now I can have a fan under the forge and a duct to the side of the blower. And I can still use the hand blower. 
Once I tacked the two edges to the forge table, I filled the lot with mud from the river. Last time I did this I had some hefty cracks so this time I mixed the mud with lawn clippings. Lets see if it works. The two openings on the edge are to have longer stock on the fire and heat the middle.   
I bought a duct fan to experiment with my blower but it turned out to be a disappointment. It claims to blow 120cfm but I think it is more like 20. Will go back quick smart. I think that an ordinary garden variety bathroom fan will do, enclosed in a plywood box and a 4" duct to my flange. One thing I don't know is how to make the fan variable. If they sold one that has 1,2,3 positions or even 1,2 like the pedestal fans ... I think I can buy a gadget to make the speed variable but it seems overkill. Would I be able to buy something like the pedestal fan have from Jaycar?

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## Marc

Would this work with a bathroom fan?   https://www.bunnings.com.au/deta-fan...oller_p4430391

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## Bros

You can't beat a vacuum cleaner for a forge. I built two for cooking crabs one coal fired one diesel. I used a bit of light pipe where it entered the forge with holes in it and a ring that slid over the holes for full air flow and slid back to cut the air back. I had access to trowel on refractory and I lined the diesel one with refractory inside the forge, the coal one was unlined.

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## Marc

Yes, a vacuum cleaner works but is damn noisy and way too much air anyway. Sure one can make a gate and deflect the excess air. 
Do you know if that ceiling fan controller would work on a bathroom fan?

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## Bros

> Do you know if that ceiling fan controller would work on a bathroom fan?

  No I don't.

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## commodorenut

The current draw of the fan will dictate the controller.  Most ceiling fans are very low current, with similarly low capacity controllers. 
I have a similar inline fan to yours, that we use for an air transfer duct.  We initially had running on an on-off switch, but flat-out was too much.
I ended up getting a controller from Fans Direct that can do a 2A load.  It's 3rd from the bottom on this page: http://fantechtrade.com.au/residential/fan-controllers/ 
Check out the specs on your motor, and choose a controller to suit.

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## Moondog55

Why mud and not fireclay/refractory? Cost? I know mud is free

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## DavoSyd

12VDC is much easier to control than AC 
look at 6 or 7inch radiator fans:  http://www.ebay.com.au/itm/12V-6-inc...QAAOSwuiNZrzv8  
plus an eBay speed controller:  12V-24V-36V-40V 10A DC Motor Speed Control PWM Controller | eBay

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## Marc

Why mud ... just because I have always done it that way I suppose  :Smilie: .
 A forge is not a kiln and does not need to insulate heat or worry about heat loss. The mud in this case all it does is provide a higher surface for the coals and a surface that will not burn. Of course fireclay would be much better. 
12V ? But then I need a transformer, and those axial fans move good volume of air but at very low pressure. 
Still thinking about what to use. I had an old vacuum cleaner I used to suck saw dust from an old radial arm saw, but don't know what became of it. Probably stopped working and tossed it out. Had a blow port too.
Godfreys used to sell reconditioned vacuum cleaners for a song, but they have shrunk to just a few stores and don't do that anymore. Must see what cash convertors has  :Smilie:

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## Jon

Just watch the roadsides on garbage night for an old vacumn cleaner

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## Uncle Bob

I'm just waiting for a jumping castle blower :Smilie:

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## Bros

The one I built was with 16" tube lined with refractory and the inlet came in at an angle and the hot gases would swirl around and didn't it get hot. I never did bleed off any air on the oil fired one as I could control the furnace with a needle valve on the fuel supply.

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## Marc

Guys guys ... I am not planing on starting a foundry, all I need is heating up iron to beat it into shape, no caldrons, no crucibles ha ha. 
The jumping castle blowers are actually easy to find and cheap but waaay to much air. 
Found an old garden blower that has a speed control built in and a gate to redirect the air towards the bag. May give that a go, probably too much air still and noisy as, but it's a start. The proper blowers made for industrial use cost around $500

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## Bros

> Guys guys ... I am not planing on starting a foundry, all I need is heating up iron to beat it into shape, no caldrons, no crucibles ha ha.

  Never know what you are up to so we covered all bases.   

> Found an old garden blower that has a speed control built in and a gate to redirect the air towards the bag. May give that a go, probably too much air still and noisy as, but it's a start. The proper blowers made for industrial use cost around $500

  Can't you just get a length of flexible hose and put it outdoors?

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## Uncle Bob

I just like to throw up anything from Oil-burner's channel. He's quite a character but I wouldn't like to live next door to him haha.

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## Marc

The garden blower did not work. It was blowing the coals out of the firepot. 
I found a manufacturer of this blowers in the US that has distribuitors in OZ, Perth to be precise and makes then for 240 and all that. You beauty ithought. It retails for $110 in the US so this may be the go.
Think again. The company in Perth sent me a quote that is worth sharing. 
Hi Marc, 
Thank you for your email enquiry, yes we are the Australasian agents for ACI.
We have attached the following quotation and literature for your consideration. 
-     Our price to supply one off Standard forge fan only Model # *VBL6/3-00105* is *$ 455.00 + GST*
o   FAN-1PH 230V 50HZ 2POLE
o   CENTRIFUGAL SLIMLINE
o   BALL BRG
o   INLET GUARD (Comes as standard)
o   76MM O/D DISCHARGESPIGOT
·         CAPACITOR BOX & 3M CABLE 
-     Our price to supply one off speed controller to suit is Model # *8-129/REE30* is *$ 165.00 + GST*
-     Our price for delivery FIS via Air freight is *$ 440.00 + GST*
o   Lead time approx. 2 weeks FIS Sydney 2170. 
So not only would I pay the usual 400% markup but also paying the postage from the US since I bet they don't have stock and direct the parent company to post it to me.
Yes ... I wonder why people are so reluctant to get their factories established here. 
Anyway, following on Bros' experience with the vacuum cleaner, found a real cheapie at Goddfries with a blow port. IT WORKS A TREAT !!!  :Smilie:  
And it's actually rather quiet at 1100W and the exhaust enclosed in the forge cowling.

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## Bros

> Anyway, following on Bros' experience with the vacuum cleaner, found a real cheapie at Goddfries with a blow port. IT WORKS A TREAT !!!

  Oh yea of little faith. Anyhow it looks good and compact.

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## Marc

Must add that it is only a temporary arrangement, Can't really work like that with a plastic tube in the way of red hot iron, but it's a start and proof of concept. My attempt at motorising the old cranking fan without butchering it succeeded. I can either build a trolley for the forge with two legs and two wheels and two handles, like a wheelbarrow of sorts and tuck the vacuum under it, or find a proper blower with a metal cowling and attach it to the metal flange I epoxied to it. 
I can't believe that I can't find a decent priced stupid centrifugal fan. Dayton has dozen of models in the US. I wonder who else uses this fans ... central aircon must move air somehow. I doubt they pay $1000 for a fan ...  :Frown:

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## Bedford

Maybe a 12 volt one? 
You'd need a power supply and I'm not sure if they'd push enough air.  http://au.element14.com/nmb-technolo...rTechnicalDOCS

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## Marc

Too small Bedford, must have between 100cfm and 200 cfm and some pressure too. 
What about this one, it says suitable for 50hz and it's 230v ??? http://www.electricmotorwarehouse.co...3FRG3_spec.pdf Dayton High Temperature Blower 229 CFM 3050 RPM 230 Volts 60/50hz Model 3FRG3 
Found a bit more information. 
Commercial blacksmith forge blower that would suit my application if it was a 240v one https://www.blacksmithsdepot.com/pro...-blower-3.html
180cfm at 80 mmH2O

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## craka

> Too small Bedford, must have between 100cfm and 200 cfm and some pressure too. 
> What about this one, it says suitable for 50hz and it's 230v ??? http://www.electricmotorwarehouse.co...3FRG3_spec.pdf Dayton High Temperature Blower 229 CFM 3050 RPM 230 Volts 60/50hz Model 3FRG3 
> Found a bit more information. 
> Commercial blacksmith forge blower that would suit my application if it was a 240v one https://www.blacksmithsdepot.com/pro...-blower-3.html
> 180cfm at 80 mmH2O

  What about a computer fan or two?

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## DavoSyd

I already posted some high cfm 12v fans but the sticking point was that Marc does not have a transformer...

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## Marc

Thank you for that Davo and Craka. I understand that 12V is easier to regulate the speed, and a transformer wouldn't be a problem. I would be $980 ahead of my "quote" anyway. 
A forge blower for what I finally understood, works on low CFM high pressure. See this comment on one of the Blacksmith suppliers website:  High pressure blowers for use with Gas, Coal or Coke blacksmith forges. These forge fans are the modern version of the squirrel-cage blower. For blacksmith's forges CFM is not as important as pressure. CFM only considers the situation without any back pressure, which is when you have no coal or coke in your pot. Static pressure gives you what you need when you are actually burning. ****Must be mounted upright - Feet at the bottom - as pictured*** Blacksmith forge blower has a cast aluminum fan housing and a fully wired motor and switch.  *112 cfm* gas forge blower 65 mmAq of static pressure,192 m³/h110 vac, 140 watt, 1.3 amp, 1/5 hp,outlet OD approx. 2-1/8"   *vac/watt = approximate Amperage calculation*  
The best high pressure blowers for forging with coal allow you to continue forging even while there is clinker buildup... it can blow right through it.  If you have doughnut of clinker at the end of your forging your blower has enough pressure *DID YOU KNOW????*  The best way to shorten the life of any blower is to overheat it. Common causes of overheating comes from low voltage and not allowing blower to use its own mechanisms to cool itself.   This is why we *do not recommend* rheostats - variable speed controls; they slow the speed and lower the voltage. Try an air gate instead  So my guesstimate for this forge is about 120 to 180 cfm and 60 to 80 mmH2O pressure.  A simple solution would be to import one from the US and run a 110/240 transformer and hope the reduction in frequency does not overheat the motor.  Other suppliers of industrial blowers in the US have a large variety of this fans and half of them state 230v and 50/60 hz so I suppose they use a squirrel cage motor that does not care for frequency. Unfortunately they don't state the pressure of their fans. From the amps stated (0.2 to 0.7 amps) they seem to be very small motors and the cfm would drop dramatically with any restriction in the airflow. There is a way to calculate how much a fan would drop when the air flow is restricted, but it requires a lot of extra information about the unit or a lot of guesswork.  
Here is another bit of trivia for whoever is interested. https://www.aircontrolindustries.com...-of-forge-fan/

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## DavoSyd

> *DID YOU KNOW????*  The best way to shorten the life of any blower is to overheat it. Common causes of overheating comes from low voltage and not allowing blower to use its own mechanisms to cool itself.   This is why we *do not recommend* rheostats - variable speed controls; they slow the speed and lower the voltage.

  rheostats change current, not voltage. 
(the speed control i posted is solid state transistor - not a wirewound resistor...)

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## DavoSyd

here's a tangent:  https://www.centralvacuumonline.com/products/smart/motors/motormodels/117123-lamb-ametek-motor/ 
low cfm + high pressure

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## Marc

Those motors would be ideal to make my own blower.

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## Moondog55

Can't you change the pressure at the outlet by starting with a high volume low pressure unit in a big duct and stepping it down gradually to a small diametre duct?

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## DavoSyd

only if the fan can handle it...

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## Marc

Low or high pressure are misnomers really in this case.  
It is possible to use a fan designed to move large volumes of air in a smooth conduit without any resistance, and make it work against a restriction like the coals in the firepot. The results are usually poor due to the loss of rpm.
If the motor has enough power to push against a restriction without losing too much airflow in the process, and without overheating, the job can be done. That means that the fan in question has the capacity to move a certain volume of air at a certain pressure. It is the result of having residual power available that results in higher pressure not the result of reducing the cross section of the conduit. 
If you are thinking in the water blast mining used by the Chinese in the Snowy and other regions, that is an entirely different concept and has to do with speed, plus liquid and gases respond in different ways to pressure.

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## Marc

Well ... got my reply from Blacksmith depot and they said don't have anything else besides 110v/60hz nad that they don't know if it is going to work on a step down transformer. 
The usual stock reply from anything outside the square with US suppliers. 
Since UK and Europe are on 50 HZ and 220v/240v a quick search in the UK linked me to a supplier in Poland.  Blowers for forges type P1 - PERUN - Blacksmith Tools 
Lot's of stuff reasonably priced ... the size of their firepot is massive!

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## UseByDate

> Low or high pressure are misnomers really in this case.  
> It is possible to use a fan designed to move large volumes of air in a smooth conduit without any resistance, and make it work against a restriction like the coals in the firepot. The results are usually poor due to the loss of rpm.
> If the motor has enough power to push against a restriction without losing too much airflow in the process, and without overheating, the job can be done. That means that the fan in question has the capacity to move a certain volume of air at a certain pressure. It is the result of having residual power available that results in higher pressure not the result of reducing the cross section of the conduit. 
> If you are thinking in the water blast mining used by the Chinese in the Snowy and other regions, that is an entirely different concept and has to do with speed, plus fluid and gases respond in different ways to pressure.

  The last sentence makes no sense. Both gasses and liquids are fluids. https://en.wikipedia.org/wiki/Fluid_dynamics
 I spent 10 months of my apprenticeship measuring the forces that are generated as a result of air in motion (or relative motion).

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## DavoSyd

walk away from blacksmith depot Marc... focus elsewhere...

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## Marc

> walk away from blacksmith depot Marc... focus elsewhere...

   Yep, that Polski website is gold. let's see what the shipping cost is. May add a few tongs to spread the cost.  
Use ... your falcon eye is appreciated. Have replaced fluid with liquid. :Biggrin: 
I hope I have not upset the Chinese too.

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## Marc

Just for illustration purposes and until I have news about the blower for the litle forge ... this is waiting the build of the bigger shop forge. 
This massive forge blower came off an old side blast forge from an era when carriages had steel tires and the blacksmith would repair them. Bought it off the grandson who is a wandering farrier. The old man's anvil is still there in the shed, easy 300 kg, sleeping. May be one day someone wakes her up. This blower runs on a very heavy 3/4 hp 1400 rpm motor. The lever is to actuate the gate that regulates the amount of air.

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