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slavetogravity
Apr 1, 2003, 1:21 AM
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At my home crag in the last few years there has been extensive rebolting happening. Consequently, there are almost as many chopped bolts as there are new bolts. Although my feelings towards rebolting “manky” bolts are mixed, I wish to try to fix the scarred rock some how. My question is, what is the best way to patch a chopped bolt. I understand some people use a mixture of resin and rock dust but I’m curious about what type of resin to use. Any tips would be appreciated.
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pbjosh
Apr 1, 2003, 1:53 AM
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Use a 2 part you mix it epoxy from Home Depot or similar, mix it while you're up there and wad the hole full. Best if you can get the old bolt out or cut it off level with the rock without scarring the rock, then use a punch and hammer the shaft as far back into the hole and out of the way as possible. Then fill the hole. Then take a little flake or chip of rock that you collected at the bottom of the crag that matches the area in question color wise and put it on the epoxy. Now hit it pretty damned hard with your hammer. Demolishes the rock into the putty and spreads the exploding fragments into the edges, does, in my opinion, an excellent job of patching...
josh
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ljthawk
Apr 1, 2003, 3:02 AM
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First remove the bolt, how to do this depends on the style of bolt. Rawl 5 piece bolts can be taken out, studs usually can't without damaging the rock. If you have a stud, crank down on the nut pretty tight to pull it out as far as you can, then remove the nut and use a big hammer to wack the stud back and forth until it breaks off; be careful not to hit and damage the rock. Then use a punch, or the busted off stud, and punch the bolt back in the hole. Some older style bolts require pure prying of the bolt with a large crow bar, such as old rivet bolts.
Next comes patching the hole, some I know use bondo with red hardener for sandstone and grey hardener for granite. The problem is bondo is a mess and you have limited working time.
I was showed a more convenient solution, it's an epoxy that comes in a single tube, most hardware stores have a dark grey version in the plumbing section. Essentially the two parts of the epoxy come rolled together as one cylinder of material. You pinch or break off as much as you need and kneed it in your hands, mixing the two parts. At Ace hardware I have found the same style epoxy in reddish / pink color, intended for wood, and light grey, intended for concrete. The reddish / pink works well on sandstone and the light grey matches light granite. Get some of the dark grey stuff as well since some rock will have dark grey patches / streaks. As already mentioned, find some small rocks and crush them up into powder / small pebbles; I use an old pill bottle to put this in. Work some epoxy into the hole to start filling it, then work the rock powder / pebbles into the remaining epoxy and finish filling the hole. The epoxy cures hard enough to be drilled / tapped, so it should last.
Another method is to just find a pebble matching in color and slightly larger then the hole. Use a hammer and smash it in the hole, creating a tight fit rock plug.
Hope this helps
L.J.
www.seclimbers.org
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piton
Apr 1, 2003, 1:48 PM
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2nd what pbjosh said use epoxy mix in sand or tiny pebbles from the area with the epoxy.
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boltdude
Apr 1, 2003, 6:57 PM
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The 2-part-rolled-together epoxies that I use are:
RepairItQuik (light grey/green tinge, good for granite/light rock)
InstaCrete (darker color grey, good for darker rock)
Both are super-easy to use (unless it's really cold, then keep them in your pocket), easy to carry, and are easy to find (2.97 in the paint department at Home Depot, although they recently halved the size and kept the same price...).
Always use rock bits/gravel/flake chunks/dust/whatever to cover the top of the epoxy.
Greg
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ljthawk
Apr 1, 2003, 7:37 PM
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Here's the epoxy at Home Depot
(Link didn't work)
Go to www.homedepot.com ----> Plumbing > Sealants > Adhesives > Epoxy
Here's the colored stuff I found at Ace Hardware
http://www.pcepoxy.com/puttyepoxies.htm
L.J.
www.seclimbers.org
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pbjosh
Apr 1, 2003, 7:44 PM
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The 2 part roll-it together grey stuff is what I've used in the past. Can't remember the brand name. Color doesn't matter much if you're decent in the smashing a rock home trick.
Most bolt holes are around 3/8" - 5/8" including the scarred area. Hopefully you didn't scar the rock too much chopping the old bolt. Pick a flake of rock (easy for granite, I haven't tried this on sandstone or limestone yet, I imagine it'd work well on sandstone, I dunno how it'd work on limestone) from the ground that matches the color you're trying to patch. The epoxy should pretty much completely plug the hole. The flake of rock should ideally be maybe 1/4" thick and 2x the diameter of the hole to be patched or bigger. Crufty rock is good, it explodes even better. Put it in place on the hole so it is stuck to the epoxy and smack it really well with your hammer. You won't scar the rock behind the patch area because the flake will absorb the hammer blow and the exploding bits of flake will, if you do it right, completely smooth over the hole, hide all the epoxy, and be very well welded into place. Much easier and less messy than trying to mix sand into epoxy and definitely quicker and produces better results. Plus if you know you're going to patch a bunch of holes you can just pick up a mess of little flakes at the bottom and keep them in with your bolting stuff and pick 'em out as you need 'em.
josh
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kindredlion
Apr 1, 2003, 8:15 PM
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Registered: Aug 7, 2002
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Great Article by Chris Mac from the ASCA, on just this topic....
http://www.camp4.com/index.php?newsid=448
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apollodorus
Apr 1, 2003, 8:25 PM
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Registered: Feb 18, 2002
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If the bolt has been chopped flush to the rock, and you want to get it out, you can try center-punching the stub and drilling it with a carbide bit a little smaller than the hole. Or you can try TIG welding another piece of steel to it. Drill a hole the same size as the bolt in a piece of steel plate, and then weld inside the hole to the stub. You can then drive knifeblade and LA pitons under the plate to give you room for a crowbar. Or if none of that works, an EDM machine will get it out, for sure.
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