Sunday, December 12, 2010

Leverage

"Give me a lever long enough and a fulcrum on which to place it, and I shall move the world."

Archimedes


Or, to paraphrase somewhat less grandly, "Give me a wrench that's bleeping long enough, and I can unscrew that bleeping three-inch iron pipe clean-out plug."

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My house has acquired a blockage in a run of three-inch iron pipe somewhere in its nether regions, and the pictured bronze pipe plug has to come out for me to be able to deal with it. The plug has been peacefully in place for decades, no doubt, and it really doesn't want to come out. It likes it right where it is.

I put my biggest adjustable wrench on that 1 1/4" square projection and wrenched at it for all I was worth -- to no avail. The plug is bronze; i.e. relatively soft, and if I round off the wrenching square's corners, it's really game over.

My son and I discussed some destructive removal method possibilities, and then I had an idea -- a rather obvious one, really; 'if what's needed is a longer wrench, then get a longer wrench.'

All well and good, but simply adding something to the adjustable wrench's handle to make it longer wasn't going to work; the bronze square's corners were too slippery to permit a longer-handled conventional wrench to be advantageous. A radically different wrenching method was called for. Here's what I came up with:

I drilled two 5/16" diameter holes through the plug near its perimeter, threaded them 3/8"-16, and that gave me a means of attaching a lever that I cobbled together from some scraps of steel shelving angle and hardwood. The overall length of my 'wrench' was about four feet, and that was sufficient. Wrenching on that freed the plug -- progress.

But I wasn't entirely out of the woods just yet. My cobbled up 'wrench' only gave me a fraction of a turn, and the plug was still awfully stubborn. But at least I'd gotten into territory where lengthening a conventional wrench's handle would pay off. Further invoking the 'bush-mechanic' genes that I inherited from my dad, I came up with this extension handle for my fifteen-inch adjustable wrench.

That did it. The plug is out. Now I can get on with the filthy business of augering through the blockage to clear the drain. (I wouldn't wish this on anyone. Talk about a ruined weekend.)

I should point out a little detail of how I assembled the 'wrench' to the plug to achieve the strongest possible interface. The bronze plug's face is remarkably thin, and I wanted to be certain that wrenching force applied wouldn't simply tear out the 3/8" bolts. Here's a detail photograph of the wrench/plug interface.


The heads of the two-inch long bolts that I used here are concealed by the steel angle. Note the hex nuts. They're tightened firmly downward against the bronze plug's face. That makes for quite a robust interface -- much stronger than it would be without them.

Were I doing this over, I'd use just a couple of lengths of threaded rod and install them as studs in the bronze plug, then place the 'wrench' over top and tighten it down with hex nuts. Using headed bolts as I did here needlessly complicated the assembly a bit.

Anyway, it worked. Here's the plug back in place with its 3/8"-16 holes plugged with short bolts and gasket washers:

Quite a good outcome; for all practical purposes, an entirely non-destructive plug removal. I used no sealant on the plug's threads, just white lithium grease. When all is working normally, there's nothing pressurized there to leak; grease will be sealant enough. (Isn't that a charming scene? My son thought it looked like the scene of an alien's axe murder.)

Next, I must tell the story of my Home Depot drain auger rental. It has everything. (Well, maybe not everything. It's a bit shy on drama and suspense and all that, and there's no sex whatsoever, but there's an act of forgery.)

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