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moTthediesel
04-08-2014, 08:18 AM
I'm run into an unanticipated (aren't they all?) problem on my current project. I'm rebuilding the dock at my Summer home on the St. Lawrence. My wife and I built it 27 years ago (it was the Fall after our firstborn showed up, so I remember the date) using local hemlock 6X6's for the principle structure. The sawyer I bought it from told me it would last for 20 years in a dock, and we exceeded that, but it now has rotted badly and has to go.

I'm using the same system to rebuild it that I employed a few years ago when I rebuilt a much larger dock at my business. There, I welded up a cage of re bar around the remains of the cribs, fabricated large frames of rectangular steel tube and angle iron that were then tacked to the cage. The center of these frames were filled with concrete to cap the stone crib filling, and then treated pine girders were bolted to flanges welded to the frames. A conventional wood deck was then constructed between the girders. I started that project in the fall, and was able to drive the vertical bars into the mud around the crib. Starting in Winter this time, I need to drill through the ice around the crib to insert the rods. Here's a couple of shots to show what I'm doing.

Tearing it up:

https://lh3.googleusercontent.com/--hCwQekfm9Q/UxD3Jy_Rp0I/AAAAAAAACRs/XUkiImed4_Q/w477-h638-no/IMG_0022.JPG

Placing the verticals:

https://lh4.googleusercontent.com/-hQw6mHKG1TI/U0PogviMV0I/AAAAAAAACkA/GXahWSbeUZ4/w477-h638-no/IMG_0025.JPG

Welded cage:

https://lh5.googleusercontent.com/-TqT3c7RdLns/U0Pomy8k4AI/AAAAAAAACkM/CEMyGrTUfik/w477-h638-no/IMG_0026.JPG

Extended drill:

https://lh6.googleusercontent.com/-Ymu3SxOABxw/U0PosUrvAVI/AAAAAAAACkY/V3Typ6B5vN4/w477-h638-no/IMG_0027.JPG

I never have had any reason to drill holes in ice before, (other than 6" holes for tip-ups) and I had no idea that it would be at all difficult, but it's been an absolute bitch! I first tried a simple flat spade bit, and that constantly jammed and was very difficult to withdraw. So then I tried a short twist auger style bit, an Irwin Speedbore, that you see in the last picture. I have had some success with that, but it's been a struggle. What does work is to withdraw the bit and pullup the "chips" after every couple of inches, but as you get further down into the ice it becomes very hard to keep going in. I would have thought that river ice would be more or less homogenous through it's depth, but that doesn't seem to be the case. At every hole, the first 6 inches or so goes fine, but then it just stops, like the ice has gotten much harder? I find that if you leave it for 10 minutes of so, you can get "hooked up" again and go down a bit further, but soon you get stonewalled again.

I have another 3 cribs to cage, so I still have a sh*tload of holes to drill, does anybody have any idea of what I might try to speed this along? It's likely that the ice will be gone in another week or two, but it makes a convenient work platform and I'd like to get this part of the job done while we still have it.

Tom

Paul Pless
04-08-2014, 08:22 AM
borrow an ice fishing auger; or run a hose from your hot water heater to where you are working and use a nozzle to make a 'hot water ice drilling jet'

Willin'
04-08-2014, 08:38 AM
Perhaps a hammer drill?

mikefrommontana
04-08-2014, 09:52 AM
I'd borrow a hot steam pressure washer and, wearing foul weather gear, use it to "bore" holes through the ice. Of course there'll be blowback of water out of the hole (thus the foulies) but it sounds a whole lot simpler than trying to mechanically drill through the ice.

oznabrag
04-08-2014, 11:15 AM
I think Paul has the answer.

I also think that what you are running into is that, as the bit hits ~6" depth it has become warm enough to melt some ice. The resultant water is then drawn up the hole where it re-freezes, causing muchas problemas.

ETA that Mikefrommontana has it going on, as well.

moTthediesel
04-08-2014, 12:11 PM
I'd like to keep the holes small, as it makes it nice and easy to set everything up. I was thinking of setting up a charcoal forge and heating up lengths of the re-bar to try melting through the holes with them. The hammer drill is a good idea too, I hadn't thought of that.

The house is winterized, and there is no source of pressure water on site, heated or not, so that's out.

Stiletto
04-08-2014, 06:35 PM
Will you wait until after the thaw to pour the concrete?

oldsub86
04-08-2014, 06:57 PM
Based on your comment that the auger style drill works I think I would try a long auger bit. It sounds like the issue is clearing the chips and the longer auger should do that.

moTthediesel
04-08-2014, 08:52 PM
Will you wait until after the thaw to pour the concrete?

Yes, the concrete will be the last thing done. On the previous dock I just tacked the decking down over the cribs so that it could be taken up for the pour. That way, the mix could be rolled out onto the dock in wheelbarrows.

moTthediesel
04-08-2014, 08:54 PM
Based on your comment that the auger style drill works I think I would try a long auger bit. It sounds like the issue is clearing the chips and the longer auger should do that.

Yes, I could try an electricians' auger bit I guess....

Michael D. Storey
04-09-2014, 02:47 PM
In my experience, what you are doing is melting the ice when you tear apart the hydrogen bond, which then re-freezes. A long auger worked for me, where the screw of the auger went up to the top of the ice.

moTthediesel
04-13-2014, 08:29 PM
Well, I got the rest of my holes drilled, but it wasn't easy. I bought the screw auger seen below, and it drilled pretty well, but it wasn't long enough to go all the way through the ice.

https://lh5.googleusercontent.com/-jltPSdTRiaw/U0svFKFtYSI/AAAAAAAACpQ/mNVSWmMxORE/w479-h638-no/IMG_0029.JPG

What I found though, was that once the hole was started, the rebar could be hammered the rest of the way through the ice without too much trouble. Odd that that would be successful when drilling was so difficult? I think that it worked because when the rod was hit enthusiastically with a heavy hammer, it actually would melt the ice directly under the flat tip, and it would go down about 1/8" with every blow. At this point I'm prepared to say that ice is a strange material to work with!

The job is going well now though, here are a couple of pictures of the cribs caged in with the steel frames mounted on top. We need to continue apace, as, at long last, the ice melting fast now!

https://lh5.googleusercontent.com/-7KqB6cszgKQ/U0swHl-61FI/AAAAAAAACqE/Tb0NFTSDCMw/w640-h480-no/IMG_0030.JPG

https://lh3.googleusercontent.com/-WIb0Msp-Jxk/U0swUDav7MI/AAAAAAAACqs/BENfzup1mFc/w479-h638-no/IMG_0031.JPG