Cherne 269883 Mechanical Plug, 1 Count (Pack of 1), Black

Anytime you use a plug like this, you're operating outside manufacturers procedures. This is not meant to fix anything permanently, but this can buy you time. The plug worked great for what I got it - I had to plug a 1/2" galvanized pipe. Of course I had to modify the plug with a larger washer, but I was also cranking this thing down until it's squat and thick, I a-b-u-s-e-d this thing. Worked great, no leaks, and I'm sure it'll do it again if I had to use it for some other unconventional enterprise.

Used this here expanding plug in two different galvanized water pressure side 1/2" pipes. Used a battery post wire brush pokie thing fer the inside to clean high quality city water skum/calcium build up, really doubt the inside walls were "honed" at all with that soft wire brush. Too bad. Hold the plug a certain depth, maybe add larger diameter flat washers on both ends of rubber as I did, then to seal the deal use that pipe repair tape & sticky hard when cured grey goop that comes with 4' long tape kit. I forget the brand but will do review soon of it. I gotz the 4' kit due to two pipe plugs. It don't drip, & hard as a rock under full pressure. Takes an ole retired Mason computer code geek to fix plumbers lack of brain cell workmanship evidently.

I needed a couple of these to plug return air vent holes in fuel tanks I'm installing on a flat bed trailer. These fit a tad loose so they slip right in - then easily tighten up to provide a solid air tight fit.

The unit worked fine. I did have to use larger diameter washers.

The rubber on this is actually .46 inches in diameter. Normally I would say that would be perfect but as you tighten down on the screw to expand the rubber the rubber is so soft that, rather than expand the along the entire length of the rubber the end piece(.445 inches) actually enters into the rubber expanding only one small area that grips the interior of the pipe. Over the next few hours, because there was only the one area of contact, the water pressure pushed the plug out of the pipe. I tried to find slightly larger washers but the fit was never perfect and the seal allowed water through. I had better luck with 1/2 inch bailer plugs. Although the shaft was considerable shorter these were actually .5 inch in diameter un-expanded. Once I got them into the pipe and tightened down on the cam they gave me a much tighter and secure fit. Neither of these is a permanent solution but simple a stop gap until I can get a plumber to fix the broken pipe. These would work (at least on a 1/2 inch copper pipe, if the rubber was a bit harder and actually 1/2 inch. The end piece should be large enough or the rubber hard enough such that the end piece is not drawn into the rubber when tightened.

I had to modify it, but it worked. Used it to plug a hole on the carburetor of my antique car.Used a cigar cutter to cut the length of the rubber in half. Cut .4” off the bolt length. Had to take about a couple thousandths off the diameter of the bolt head. Had to use a little grease on the rubber to get it in the hole. Tightened it up snug and it should work.

When you tighten it, it will pull through the rubber.I added stiffer rubber on the bolt, inside the rubber to stiffen it

The negative reviews gave me pause. I had accidently sheared off an outdoor 1/2 inch copper pipe. It was an emergency and because of the freeze in Texas all of the plumbing supply stores were low on stock. I bought this product and it worked like a charm! It took seconds to install and there were no residual leaks. It was a perfect step until I can do a full repair and attach a faucet.