Never Do Things Right
January 5th, 2009You Will Pay in the End
I become more amazing every day.
I had three bolts broken off inside the wall of the tube on my table saw. How the previous owner managed to break them is a mystery. I had to get them out. I drove to Home Depot and bought an extractor.
I drilled a hole in the end of a bolt, planning to use the extractor. As soon as the bit went through (the bolt remnant was very short), the bolt popped through the bolt hole and disappeared. I guess it caught on the bit, and the bit turned it. Same thing happened on the second bold. On the third, I decided to be safe and use the extractor. I opened a hole, stuck the extractor in, started turning…and it snapped, leaving a piece of hard steel embedded in the bolt. Nice.
This is what I get for doing something right.
The great thing is, this gave me an opportunity to use my diamond rotary bits. I can’t remember how I ended up with them. Ebay, I guess. They’re for rotary tools like Dremels. I experimented with several, and finally, I found one I liked. I opened a nice big cavity in the bolt, hopefully with no extractor bits left in it, and I went to work with the drill again. Pretty soon the bolt disappeared, just like the others.
This is the beauty of having too many tools. You can almost always find something that will do what you want.
I got the saw set up (rails but no extension), and I tried a saw-calibrating method I had heard of. I crosscut a piece of wood with an X drawn on it, and then I mated up the sides, turned one piece over, and mated them again. The wood was about three inches across. I think there may be a tiny error of a small fraction of a millimeter, but it’s so small, I’m not sure. I put the pieces of wood together and checked them every way I could, using a square and straightedge. I noticed that the miter gauge from my Ridgid portable gave a better result than the nicer of the two gauges that came with the Powermatic 66. I guess it’s possible that the error came from the miter gauge.
The Corian blade made a very nice cut, but it seemed slow.
I was able to park the saw next to the wall with the rails on it, but I discovered that I was no longer able to open the car door. So things had to be reorganized. But now that the saw is on wheels, I don’t really care. Wheels seem to be the secret to successful small workshops.
Things are looking up. It’s pretty clear that I can put enough stuff out there to be able to tackle most problems and projects. I may even steal my cousin’s plans and build a cyclone.
January 5th, 2009 at 7:37 PM
Corian blades are made so that they take a very small “bite” of material with every tooth. It’s the way they’re sharpened, not the amount of space between the tooth that counts. other types of blades are more aggressive. You can have the corian blades resharpened to improve the rake and heel angle- Jim Dunmeyer will be able to tell you how or direct you to someone who can. Or you can just save them to use in- hell, I don’t know- corian? You;ll be surprised how nice Corian is to work with. Avonite, too.
January 5th, 2009 at 8:14 PM
Those crappy screw extractors NEVER work. And good luck trying to drill it out…
I have a set of great extractors recommended to me by a mechanic friend. However, they’re in one of my work trailers and I can’t for the life of me remember the name. Google isn’t helping either.
January 5th, 2009 at 8:20 PM
There are amazing left handed drill bits for extracting stuck / broken bolts. As you understand now, the act of drilling the bolt out frequently loosens up the stuckness. With the lefty bits, the loosened bolts back merrily out, leaving the hardened extractor unfulfilled and longing for the next project.
Lubricants, vibration, heat/ cooling cycles, and electrolytic rust removal (google it- Great piece of modern mechanical knowledge) techniques all have wonderful effect on stuck bits.
Mark
January 5th, 2009 at 8:24 PM
I hate extractors. This may be because I’ve never worked with good-quality ones, but as with your experience, they break.
What I like for bolt extraction is left-handed drill bits. Soak the broken bolt in rust-cutting lubricant like Liquid Wrench®, then use the left-handed drill bit to do what you did, except that the bolt comes out rather than being driven in. I really don’t want broken-off pieces of bolt lying around in the water channels of an engine block, for instance.
One thing: drill bits used for removing broken bolts should be slightly dull. The extra heat generated is an important part of the process.
Regards,
Ric
January 5th, 2009 at 8:34 PM
Have you ever heard the term “choking the saw”. If you haven’t, then you’re gonna find yourself getting unsatifactory cuts on material in the future. Especially if you’re cutting thick or very dense stock.
January 5th, 2009 at 9:20 PM
Here is how we remove broken bolts on our blow molding machines. Normally the ones that break are on the die heads and are either 3/4 or 7/8 hardened steel bolts. They break if for some reason the machine hasn’t reached proper operating temperature and the operator starts up the screw pump to start pulling plastic resin through. Since it’s not properly heated it won’t flow through the die and builds up enough pressure to pop off the bolt heads and launch the two hundred pound die head forward until the attached cables catch it or it smacks the operator a good one and sends him to the hospital or worse.
Anyway, since they are hardened steel we carefully weld a piece of rebar or small piece of steel to the exposed end of the bolt then turn it out with whatever tool we can get on it that will make it move.
I know you are just dealing with tiny bolts in comparison but this trick will work on them too and is much more frustration free.. As long as you can get anything welded onto the end of the bolt you will be able to turn it out. The heat from the welding is a help as well. Oh yeah…. here is how you can justify an oxy-acetylene rig. We usually hit reluctant metal with some good heat too, to speed things up.
January 6th, 2009 at 7:48 AM
My Dad got Doug Stowe’s basic box book for Christmas and I recognized the name from your postings. I ended up reading it cover to cover in two days. I am eager to try some of the techniques such as the miter sled and the hand cut dovetails (I don’t expect to succeed the first time).
.
I see why you are a big fan of his.
January 7th, 2009 at 4:38 PM
I’d save that Corian blade for when you need a very smooth cut; the slowness of the cut will be offset by not having to sand/plane/joint the edge.
I’ve used Leo’s method of removing broken bolts/studs many times and have never had it fail. There have been times that I’ve had to weld a nut to the stub more than once, but I’ve always been successful in the removal.
The ONLY screw extractors that are worth anything are the tapered square jobs. Take those ones that look like coarse, left-handed screws and pitch them in the trash.