enlarge a hole

[Prashun Patel]

I'm replacing a bad frost-free hose bib. The existing hole is 12" long x 3/4" wide. However, the newer hose bibs are slightly wider, and I need to enlarge the hole to 1". What's the easiest way to do this?

I thought of gluing in a 3/4" dowel and then redrilling with a spade bit.

Any other solutions?

[Jerome Hanby]

Not sure what is around the hole, but if it's flat, you could just tack a piece of scrap over the hole and use a small hole saw...

[Brian Vaughn]

I would start the hole using a hole saw, to 2" depth or so, then swap to a forstner and finish. The hole saw could just be visually centered, an taht part of the hole would work to keep the forstner bit centered.

[Lee Schierer]

If the existing hole is fairly smooth sided and round, you can insert a short piece of dowel in the existing hole and start drilling the new hole. If the dowel is loose enough the drill will just push it through the hole as the bit cuts the outside. This will make the drill bit work like one of those plumbing fitting repair bits,

[Rich Engelhardt]

www.buyhardwaresupplies.com/?t=5&itemNumber=4303459

Moen makes a 1/2" sillcock.
That should fit in the exisiting hole.

BTW, are you sure the whole thing needs replaced or just the washers?

[Ryan Mooney]

To expand on the dowel idea from Lee.. If you cut a short dowel plug that fits the hole, predrill the center (with like a 1/8 or less bit - just for centering) and then thread it onto the screw end of an auger bit you can use that to have the auger follow the hole hole down (this works even if the hole is kind of wonky because you don't have to have a very large piece of dowel to follow). Putting another board overtop with a starter hole drilled to get the process started helps to.

[Kent A Bathurst]

To expand on the dowel idea from Lee.. If you cut a short dowel plug that fits the hole, predrill the center (with like a 1/8 or less bit - just for centering) and then thread it onto the screw end of an auger bit you can use that to have the auger follow the hole hole down (this works even if the hole is kind of wonky because you don't have to have a very large piece of dowel to follow). Putting another board overtop with a starter hole drilled to get the process started helps to.

OK - now THAT is officially clever.

[Michael Peet]

Drill a hole the size you want in a thin scrap, then clamp that in place where you want it over the existing hole. Use a forstner bit in this template; it will keep the bit on target until the new edges are established.

Mike

[Brian Gumpper]

Does the hole need to be 12" deep like the original? If it's shallow, I would use a 3/4" forstner bit in a drill press and set it up so the bit fits in the hole then you'll have your center. Then you can put the 1" bit in and drill away. I don't know any easy way though to make it 12" deep except for an auger bit bit I don't know if they go that wide.

[Ryan Mooney]

OK - now THAT is officially clever.

Heh, I can't take full credit.. I was reading Audels Carpenters and Builders Guide before I saw this post (available in reprint at lee valley - well worth the price imho, if only for the steel square section - which is also available as an exceprt) a couple of days ago and they actually explained a process very similar to that (if you are going to steal steal from the best )

I also found the math section that went from 1+1 to basic trig in ~30 pages to be somehow compelling (granted it wasn't anything I didn't already "know" but the conciseness of it was impressive).

[Prashun Patel]

Thanks, All.

The hole enlargement needs to be the full depth of the rim joist.

I did a test by lodging the end of the hole saw pilot bit in a 3/4" dowel. This guided the 1 1/8" hole saw perfectly.

[Larry Edgerton]

Another way if you have one is to use a sheet metal step bit to get the hole started at the larger size and then finish with a forstner once the size is established with the step bit.

I like the dowel idea, clever.