Induction forge

[B.Finnigan]

I have been wanting to get one of these for a couple years and finally went for it. It still needs the Dynaflux R1000 cooler which should be in by Mon. Grant Sarver of Off Center Tools is the dealer for them and only lives 30 minutes from me. He has been very helpful in showing me all the bells and whistles on it.

It uses 220vt at about 40 amps and the cooler uses 110vt. Since my shop is not heated I will use the anti-freeze coolant for it. It comes with a foot pedal and three different sized coils. Grant has shown me several other coil configurations that can be easily made with copper line.

For those of you not familiar with induction heating put simply it's similar to a microwave oven except for metal. It will heat both ferrous and non ferrous metals as well as graphite.

The advantages of an induction forge are:

No propane to buy at $3 a gal here.

No lugging tanks back and forth to be refilled.

Here in the PNW power is cheap.

It does not heat up the shop since only the steel gives off heat.

Pinpoint heating allowing some unique forging possibilities.

Far better heat control and monitoring steel color.

Mokume and pattern welding will be more precise.

The coil can be operated inside and inert gas environment vastly reducing oxidation.

It's programmable for both power level and heat time allowing precise consistency in repetitive tasks.

The ability to cheaply and easily make specialty or custom coils to fit a given task.

Faster initial heating and even faster re-heats.

Can be kept closer to your anvil or stake vise.

No insulation refractory to maintain/replace or particulates to breath.

No CO/ventilation concerns.

Quiet operation.





This is not my video but it shows how fast it heats steel.

[cdent]

Congrats Brent,

You're probably aware of it, but there's a good thread about this in tools over at Don Fogg's forum. A little mention was made, but this forge may also be an interesting option for some heat treating.

Good for you, Craig

[rhrocker]

Really a neat inovation, I can see all kinds of possibilities with this (forge on your kitchen table in your apartment ::::::) B, I have to ask, can you give us a sense of cost for a unit like this? Also, can you heat up say a 8" section by moving the bar (or blade) back and forth?
Robert

[B.Finnigan]

The forge is $3400 with WA sales tax and the cooler is $800. But since OCP is real close I didn't have to pay the $100 for shipping. The only expenses left is to wire up the power cord. They don't come with one, just a junction box and copper screw terminals. Then I need some hose fittings to connect the cooler up.

They will heat up lengths of steel by moving the steel back and forth within the coil. Most of the videos posted show just whats inside the coil to illustrate the speed.

This vid shows how it heats lengths very quickly.

[Ed Caffrey]

These are certainly "Cool Tools!" The first one I ever used belongs to Tom Ferry, and I've been trying to justify one ever since. What's held me back so far is the cost to uses ratio. (and the fact that I'm trying to save up for a new truck )

It's one of those tools that allows you to do things that no other tool can... spot welding billets, very controlled/localized heats, etc.

Maybe one of these days!


Congrats on acquiring it!!

[B.Finnigan]

They're certainly are not a "need" tool but there is a huge convenience factor to them. And a chunk of the cost will be offset with the savings on propane. But I won't claim for a minute it will ever pay for its self with propane savings.

I got it just add a bit more fun to a hobby I already enjoy. Magic is cool but physics is even cooler. A friend of mine is a tool and die maker for Boeing and induction is all they used for HTing. So I can see in a high volume industrial setting the efficiency, consistency, size and safety of using them vs gas or convective heating.

[B.Finnigan]

I built a retractable and telescoping stand for the forge. When not in use I can remove the upper coil plate and then retract the base back under the bench. The top plate will have a piece of high alumina refractory to insulate the aluminum plate from RF and heat. Then I will have two furnace bricks on each side of the coil with a groove cut into them to support the work piece while in the coils.

The two slide arms can be locked in place with the two tension knobs to keep the whole stand stable. The upper telescoping rod can slide down below the base if needed. I wanted a lot of adjustment flexibility for the base since I will have many uses for the forge.



The power cord is wired into the forge, the cooler hooked up and I flushed out the forge and cooler. Tomorrow I will fill it with coolant and fire it up. The cooler is made in the US

[B.Finnigan]

I finally got it all wired up and plumbed into the cooler. It's pretty awesome how fast it heats a 1/2" square bar.



Cutting and welding with radio waves.

[plain ol Bill]

Hey Brent - those things are COOL aren't they. I have had Tom Ferrys in my shop several times and boy are they fun to play with. If you should happen to pop a hole in a coil you can do a quick repair using JB Weld Quik. Just take the coil off, drain it and apply a coat and wait a couple of minutes and it will be good as new.

[B.Finnigan]

Bill good to hear from you again! That is a good tip to keep in mind. It make sense since the coil stays very cool. I was out forging a small blade this morning and it's insane how fast it will heat and re-heat a 3/16 x 1" wide bar of 1084. Plus I was just using a small 14" length and never had to use tongs or gloves.

The shop temp never went up a degree and I never broke a bead of sweat.

[rhrocker]

Leak? The coils can leak? What's in them, nuetrons, protons, electrons? All of the above? Knife heating up fluid? Ok, I guess it's the H2O that the cooler moniters, but I had no idea it flowed through those coils. Makes sense though!
Robert

[B.Finnigan]

I am running an antifreeze coolant in mine since my shop is not heated. Plus it's a corrosion inhibitor, pump lubricant and prevents bacterial growth. The Dynaflux pump runs up to 80 PSI but I have mine set at 50. 2-3 seconds after heating a chunk of steel you can touch the coil.

The forge has a pressure switch inside that will not let it work unless coolant is running and at the correct pressure.

The only thing that should leak out of the coils is electromagnetic power, lots of it.


There is going to be a bit of a learning curve on how to use this process compared to gas. It's pinpoint heating potential can also become pinpoint cutting within two seconds past bright orange. This was 1/4" by 1" 9260 .




But you can also see how clean the steel is after 45 mins of forging. The pitting is very fine since you have perfect color monitoring while heating. By not looking into a glowing orange forge the color is very easy to watch. That is unless you try to push the envelope a bit on smaller stock.

Hopefully the induction gods will not be exactly too many more sacrifices to keep them appeased.

[B.Finnigan]

For those of you that are not sure induction heats blades evenly watch the video. The steel is 1084 3/16" tapering down to a wire edge. I normalized it twice before the HT.



You can see there is no pitting or scale. The burnt oil on the edge wiped off clean and you can still see the wire edge that did not burn. You can see there is no pitting or scale. The burnt oil on the edge wiped off clean and you can still see the wire edge that did not burn.

Induction tends to heat the thickest part of the steel after CT which is perfect for blades. It would be very hard to burn the tip unless you intended to. Since the edge and tip have less density it heats slower. The exact opposite of convective heating.





This little 2.5" blade hit CT in 3 seconds and even after soaking for 30 seconds while moving it back and forth the wire edge did not burn off.

Another observation is I can feel small magnetic vibrations while the steel is heating and when it hits CT I feel the vibration stop. So it has a sort of a CT alarm, especially on smaller pieces. No need for a magnet, it is the magnet.

[B.Finnigan]

I made up a couple custom coils.

Edge HTing.




Tomahawk/hatchet coil.

[B.Finnigan]

The one minute copper guard from scrap.



My graphite quarters crucible works even better with induction. It holds nine quarters and even if they get a bit too hot they will stay homogeneous and not alloy.