This story would be funny if it happened to anyone else. Enjoy if you must, help if you can.
We are proud owners of a 40 year old York chiller. It is unique in the industry for having an electric block heater that resides in a well in the cast iron block of the compressor. The compressor will not start unless the oil temperature is high enough (the cast iron gets hot to the touch, probably ±140°) to prevent pumping Freon 11, a notorious solvent, through the bearings. The heater is about 8" long and 5/8"? made of stainless (no, I don't know what grade) with ceramic and a heater coil sealed inside. You would also need to know that due to controls, framing, and sensors the path to this well is about 20" away from anywhere you could have a drill motor. The well bore is horizontal. I did not have my bore gauges with me but a 3/4"? drill shank will NOT go in the bore.
The heater shorted and failed and in the process, apparently, welded itself to the bore of the cast iron well. The old heater is basically out, but the bore is not clean enough to let the new heater in. One of our technicians welded a 5/8 reduced shank to a1/2" rod and launched into the bore. He made some good progress and then snapped the weld, he was able to get the drill back out. No problem, we had made up a 5/8 reamer on a cold rolled shaft for a previous similar problem on a different York. We had used it by turning it with a crescent on some flats. This guy decided that this would be too slow, so he chucked up the shaft in a hand held electric drill. DO I REALLY HAVE TO TELL THE REST OF THIS?
I was invited into this problem late Friday. There is about 11/2" chunk of broken off ream in this bore. The end of the piece of ream is 3 1/2" deep in the bore. The ream shattered at an angle. I was able to get a long thin screw driver into one of the flutes, but it is well jammed and I couldn't get anything to wiggle. It was decided not to deal with it until Monday due to Easter and an unusual cold snap.
I drilled a 1/4" hole through a 5/8 bolt to act as a drill guide. I left the head on to keep it at the face of the bore and have a stack of O rings to center it in the bore. I have a new package of taper length 1/4 cobalt bits that can just reach the back of the ream and drill about 3/4". I have a half dozen new 1/4" masonry carbide bits. I can turn the 1/4" bits with 2 Irwin speed bore extensions. We discussed a tap extractor, but I fear the ream is jammed far too tight.
Wish me luck. Say an extra prayer. Hurry up and give me some other advice. Rainy days and Mondays are bad enough on their own, I'm feeling challenged about tomorrow.