Author Topic: Resurrection of a CFEI 100 KVA Induction Furnace  (Read 30345 times)

Offline hermetic

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #750 on: February 20, 2021, 02:52:05 PM »
Jammy dog, I had to pay 17.95 for mine!!
Man who says it cannot be done should not disturb man doing it! https://www.youtube.com/user/philhermetic/videos?

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #751 on: February 21, 2021, 06:13:45 AM »
They are only a tenner iirc anyway Phil.

So not being able to get on with the hearth itself due too lack of materials I decided to re-make the coupler that joins the torch gas lever valve to the torch flexible hose, but incorporating a choke or jet to reduce the gas flow. As it was, if the gas was fully on a dangerously long yellow flame was produced. The 1/2" BSP lever valve  presents a female socket, and the original adaptor was a short stub of 1/2" pipe threaded both ends with a slight socket boring into one end to receive the 60 degree male cone on the flexible pipe. A bit crude and of course 'full bore' at 1/2".

I made one from a bit of hexagonal steel which gives the advantage of flats to put a spanner on when tightening. Jet end drilled 3 mm, female cone end drilled 6 mm then bored to give a good area of 60 degree taper with a big centre drill (BS7 3/4" Body).

Now if lit with cocks fully opened at least the flame isn't stupidly large and can still be controlled by the lever valve on the manifold and the knob on the torch itself.

Andrew Mawson
East Sussex

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #752 on: Today at 09:16:07 AM »
Well Flamefast came up Trumps :thumbup:   (cards that is not politicians !)

Were I to make a donation to a nominated charity they would pop some bits in a box and send them to me - a refreshing way of doing business ! That was Monday afternoon, today (Wednesday a box arrived containing 5 kgs of rather special 'RCF Mastic', an 18" square of 4 mm pretty solid Kaowool blanket,  Two face masks, two pairs of nitrile gloves AND the proper propane jet  :ddb:

A bit of careful marking out and cutting and the kaowool was reduced to a 12.5" disk with a 7" hole in it ready for use as a thermal barrier between the ceramic tile and the metal plenum chamber.

I then 'caulked' the joint between the plenum chamber and the quadrant tiles with the RCF mastic forcing it as far into the joint as possible as it is this seal that had previously been leaking.

Then fitting the Kaowool disk with the perforated tile on top I caulked all round the tile forcing as much as possible down into the gap. Having got as much in as I could with a putty knife I then forced it further in with a wooden lath cut to size. Another two  trips round the tile with the putty knife pushing the mastic in as far as possible followed by smoothing with a wet trowel and a damp cloth. This seal HAS to be good or the whole rigmarole that I've been through will be a waste of time.

Asking how long to leave the mastic I was told that in the factory they hit it with a gas torch, make it sweat, and then it's ready ! OK I used the forge torch to dry the surface then put the ceramic chips back in and lit the forge, reasoning that hot chips are no different than a darn big gas flame to dry and cure the mastic.

Initially clouds of rather nasty smelling steam then after about 5 minutes things began to clear and the chips started to glow. After ten minutes I'd swear it's hotter over a more even area than i can ever remember it. So with much of the bulk of the ceramic chips glowing white hot I turned it off in the interest of conserving propane  - I'm sure that the mastic will now set nicely.
« Last Edit: Today at 10:36:15 AM by awemawson »
Andrew Mawson
East Sussex

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #753 on: Today at 09:23:50 AM »
Comparing the 'original' propane jet that was in the forge when I got it to the one sent by Flamefast convinces me that someone has altered the holder from 1/2" BSP to M 12, but what is important is the hole for the gas - how big is it?

My currently installed one is 3.5 mm as that was as close as I could get to a #28 drill. I'd been told recently by Flamefast that the jet should be 3 mm, but NO! This jet actually measures #29 (yes I now have a set of number drills!) or extremely close to 3.5 mm so I'm not going to change anything.

« Last Edit: Today at 10:40:26 AM by awemawson »
Andrew Mawson
East Sussex