Resurrection of a CFEI 100 KVA Induction Furnace

[awemawson]

My days began with the best of intentions to carry on dismantling the old chiller and recover anything worth saving, but first one of those '5 minutes jobs' got in the way:

. . . Identify what model of Briggs & Stratton engine my ancient 2 kW generator has, and order a replacement ignition coil. Well the model number is stamped into the cowl Google tells me, and I'm sure it once was, but at least 30 years of rust and Hammerite have rendered it illegible even after much cleaning. Looking at pictures on the web I'm pretty sure that it's a 3 HP 80232 with a 'points and capacitor' set up - coil is O/C. Almost identical ones available on eBay and from gardening on line shops BUT their mounting holes are 64 - mine is 59 mm  centres 64 mm one ordered and it looks like some machining is in order to modify the replacement, but those holes are through the lamination so that's going to be fun!

So at last back to the chiller - I've decided it is not worth re-working the case - I will make a skeleton one out of heavy box tube giving a much smaller footprint  so no point in more case dismantling - the scrap recipient can do that!

So I removed the entire control box with it's various useful breakers and relays, and also the huge extractor fan that sat on the lid, and then turned my attention to the water tank.

An angle grinder took care of the internal copper plumbing allowing me to remove the copper evaporator as a complete unit (lucky scrap recipient - it's heavy and solid copper!) and then cleaned the tank using my petrol pressure washer - it's not come out too badly.

This tank is 110 litres /  or 24 UK gallons so reasonably sizeable - I think a frame about 30 x 24 inches should accommodate the tank and pump on the ground floor, with the heat exchanger and other controls a bit higher up. I ordered some cheap imported LED temperature indicators on ebay so that all ports of the heat exchanger can be monitored - so a front panel mounting them, the start / stop for the pump and anything else I've forgotten can be up at eye level.

While all this was happening the pipe and plumbing fittings were delivered - so a quick goods inwards check to see that it's all there - yes it is but I'm sure I've forgotten something - always seems to happen with these projects!

[nrml]

It would be nice to turn all that copper into bronze as your first melt.

[awemawson]

It would be nice to turn all that copper into bronze as your first melt.

I have a chap who is very generous with his time helping me with things that anno domini is making more difficult as the years go by. He is scraping a living in agriculture not very successfully so I let him have my scrap as he always refuses to take payment. This way I can disguise it as actually helping me get rid of junk 

[AdeV]

It would be nice to turn all that copper into bronze as your first melt.

You beat me to it....  I've got a pile of solid 6mm copper wire here for the old overhead gantry crane  - which, to avoid coils of wire hanging around the place, literally ran in similar fashion to a railway train, with 3x bare conductors and sliding pickups), if I ever get Rob Wilson's old furnace going, I'll definitely be making some copper ingots...

[awemawson]

Funny stuff to cast, copper. Very fluid.

Pouring down here and I’ve just been out to the ‘soon to be’ foundry to find numerous leaks in the roof

It’s a fibre  reinforced cement ‘big 6’ roof in good condition only 10 years old but laid to a fairly shallow pitch. Leaks are at sheet overlaps so I’m hoping that maybe there is a build up of leaves from a large tree close by. Too much rain to look at the moment. Don’t fancy drips into the high power electronics 

[awemawson]

The rain has subsided to an annoying drizzle, so I was able to put a ladder up and look at the foundry roof. Sure enough there IS a bit of a build up of moss and  rather too much overhanging willow tree. I expect that the water isn't clearing fast enough and is tracking back up the overlapping joints when the rain is heavy.

Talking of heavy rain - the bore hole is now OVERFLOWING 

The Black Jack to paint the newly cleaned manhole frame and cover has arrived, but that can't go on until the weather changes.

[hermetic]

Odd that a borehole so deep should react so fast to rainfall, but no matter, it is all to the good as far as the project is concerned!
Phil

[AdeV]

Well, that explains why the lid was so rusty - it's probably been being soaked from the underside on a regular basis for the last 50 years!

[awemawson]

Probably so Ade !

I'm hoping to be able to incorporate an overflow pipe at the level of the lowest brick course. I happen to have a run of perforated ground drain not very far from there, (albeit the other side of a Portakabin) that joins into the main run of surface drains to the stream - with any luck I can intercept it and join in.

[nrml]

There must be some artesian well type of effect taking place. Is there anything in the local geology to explain this?

[awemawson]

Not really - OK we are pretty well towards the bottom of a very shallow valley - but it's all pretty clayey - the bore hole is at a low point in the goose area so it could just be the massive downpour that we had.

. . . an over flow . . .that's what's needed 

[Pete.]

Not really - OK we are pretty well towards the bottom of a very shallow valley - but it's all pretty clayey - the bore hole is at a low point in the goose area so it could just be the massive downpour that we had.

. . . an over flow . . .that's what's needed 

Looks like you got one

[awemawson]

So this morning it was a case of "out with the old, and in with the new".

Old Chiller chassis palletised and dragged out to make a bit of space, I did save it's castors as it was easy to when hoisted up with the forklift!  And then I finished off cutting the box tubing for its replacement that I started yesterday. I need to clear space in the welding shop before I start putting it together - of course sods law dictates that it's slightly too large for my welding bench !

Meanwhile intensive tree pruning to remove branches overhanging the foundry roof - personally I'd just fell the tree, as it's only a scrubby willow but it's not on my side of the boundary. I'm sure the water board (who we neighbour) would have no issue with me introducing it to a chain saw, but getting to speak to the right person is neigh on impossible.

[awemawson]

Raining hard again this afternoon, so the welding shop didn't get reorganised (much easier when things can be temporarily be moved outside)

But I did strip the peeling paint off all twelve cross members ready for welding. I didn't do the four uprights as they will be far easier when the bench is moved to a more convenient place - hopefully tomorrow.

I used grizzly stripping disks - these take paint off at a great rate of knots  and are slightly kinder to the underlying metal than coarse sanding disks. They are also EXCELLENT at taking the skin off your knuckles! Amazingly I found that I had a box and a half in stock from some other project. Used three so far.

These box sections are very heavy dip galvanised and I wanted to leave as much zinc on them as possible.

[awemawson]

A major push this morning to dig my welding bench out from the accumulation of encumbrances that have  built up around it - various  welders (which I suppose are justifiable next to a welding bench!) and other junk not so justifiable.

Then finding a home for the multitude of clamps that normally sit clamped to the edge of the bench, and removing the very heavy vice, and a pile of rather nice fire bricks (thanks Pete. !) I was able to pull it out to a position where the frame that I'm about to weld up can hang over the edge, and be worked on all round.

About then my oil boiler man turned up to service  the three systems we have on the farm and repair the oil level monitoring system, so activity had to cease.

I did however manage to plot the route of the ground drain that I want to intercept for the bore hole overflow, and start the digging of a trench from the bore hole to the fence, the other side of which the drain runs about three foot out. I have a 'CAT and Genny' - ie a Cable Avoidance Tool which is fine for metal pipe and cables but not plastic pipes. So again my 250 metre long reel of fibreglass ducting rod came in handy, tying a random length of wire to it, and threading it down the drain, attaching the other end to the genny. Worked an absolute charm. (Picture rather fussy - rain pouring down - taken from under an umbrella !)

Hopefully tomorrow will see the four frame uprights paint stripped and welding can commence.

(later edit: for the record so that I can refer back to it if I need to, the detected field drain is 69 " from the face of the fence)

[awemawson]

I was determined to get the four six foot long upright box sections stripped of their paint today, so grabbing a cold (cooked!) sausage in lieu of breakfast I got out early before other things distracted me.

Four stripper disks later and about an hour and a half of angle grinder time not only was EVERYTHING covered in paint dust but the uprights are at last stripped.

. . . let the welding commence 

[awemawson]

I'm sure this job is jinxed 

I had set up for the first weld and then was conscious of a hissing sound  A bit of hunting about and I found that the plastic upright tube of my 'Peashooter' Argon flow gauge was leaking where it screws into it's base / tap / outlet thingy.  At £160 per bottle leaks cannot be tolerated !

Fortunately I was able to unscrew it by the expedient of wrapping a bit of 200 grit wet and dry round it and gripping in the lathe chuck, expecting it to crack at any moment. It unscrewed  suddenly with a flurry of ball bearing / inner tube and odd shaped plastic spacer falling in the swarf !

OK it just needs screwing together with something to seal the threads. Being plastic I'd usually use PTFE tape but getting the ball, inner tube and spacer in necessitated partially threading it on first so non too easy with tape. I resorted to Loctite 542 that says on the bottle 'do not use on plastic fittings' - well I did !

It needs a bit of time to cure, so I stopped for an early lunch. After about 45 minutes it seemed at least partially cured so I re-assembled it on the regulator and resumed welding.

All went reasonably well. I've finished the first 'frame' which could be front or back, left or right as it's symmetrical.  Not surprisingly there is a bit of a twist in it, only about 8 mm but I should be able to pull it back when it's got the rest of the bits welded to it.

I'm quitting while I'm ahead and will resume tomorrow as the oil boiler man is due back this afternoon.

[Spurry]

Looking good so far.  Do you use anything special when welding galvanised steel in the way of breathing apparatus?
Pete

[awemawson]

Wide open doors both ends of the welding shop and hope the fumes clear before they get you !

The galvanising certainly gives a greater tendency to porosity, and the flare from the burning zinc when the arc starts can be a bit distracting. If these were critical welds I'd strip the zinc with acid first but they aren't. As usual it's massively over engineered!

[Pete W.]

A one-time neighbour of mine worked as a welder.  I asked him about welding galvanised items and he said the thing was to drink lots of milk.

Is that founded on reality or is it an old wives' tale? 

[mattinker]

A one-time neighbour of mine worked as a welder.  I asked him about welding galvanised items and he said the thing was to drink lots of milk.

Is that founded on reality or is it an old wives' tale? 

I can't remember why, but it really does work!

Regards, Matthew

[awemawson]

Yes I've heard that as well, but I just went and drank copious cups of tea 

[nrml]

Milk is a source of calcium. The belief was that calcium would act as a chelating agent reducing the damage caused by the metal in the body. Unfortunately, it isn't true.
https://safe-welding.com/milk-against-welding-fumes-not-much-more-than-an-old-wives-tale/

[Spurry]

Snippets appreciated.
Pete

[mattinker]

Milk is a source of calcium. The belief was that calcium would act as a chelating agent reducing the damage caused by the metal in the body. Unfortunately, it isn't true.
https://safe-welding.com/milk-against-welding-fumes-not-much-more-than-an-old-wives-tale/

nrml,

Thanks for your link! So I was wrong! I've been trying to remember where I'd heard about milk for fume fever. I've come to the conclusion it was nearly fifty years ago when I trained a mechanic, we had gas welding in our training, so I'm sure it was then, as I've had very little formal training in welding! I have had fume fever from welding galvanised steel, milk certainly feels good when it goes down, but OK, that's all it is then!!

About ten years ago I had mild heavy metals poisoning, abnormal levels of Lead, antimony, Cadmium, mercury, Aluminium and arsenic! (Arsenic is not a metal, but is grouped in with the metals as it is the same kind of poisoning) The lead was explained by untested well water in Wales, but the rest was unexplained! I was treated for it. I discovered that fresh Coriander is a natural chelation, so I regularly treat myself to copious amounts in my diet! Coriander should also work for fume fever!

Regards, Matthew