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Minerals
Novice climber
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Oct 17, 2002 - 02:03pm PT
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No worries Clementine. In the case of 1/2” vs. 12mm, the difference is the opposite.
1/2” = ~12.7mm, a little on the big side. I can see how this might present a slight problem.
Sharpening:
It depends on if you want to sharpen an SDS bit or a high speed steel bit.
I like HSS because you can sharpen them (on a standard grinder) to a chisel (flat) point that is sharper than the tip of an SDS. Don’t worry about getting the bit too hot and turning blue; this is OK. HSS bits will become dull more quickly and sometimes bind if you don’t remove rock dust periodically with a blow-tube but drill much faster when they are sharp. You can sharpen them on the rock between holes. HSS bits are cheaper than SDS and can be found at any hardware store. A collet type drill holder is required for these smooth shank bits. I recommend the Hurricane – an excellent design. Extra collets of various sizes can be purchased through the manufacturer or through a machine shop supply co. This allows the use of odd sized bits such as 17/64” and 11/32”. The standard 3/8” collet that comes with the drill will accept 25/64” HSS bits.
Sharpening SDS bits is a bit tricky. A special ‘green wheel’ (silicon-carbide...???) is required. If you try to sharpen one on a standard wheel, it will eat right through the wheel. Again, check with a specialized hardware store or machine shop supply co. for one of these wheels. Extreme caution is required while sharpening. Do not get the tip too hot!!! Grind for a second or two (no more) and then dip in water to cool. Do not apply too much pressure. Even with great care, I have had some SDS carbide tips fracture and explode while drilling, making the bit worthless. Sharpening SDS bits is kind of a hit-and-miss process. Sometimes it works and other times it doesn’t. Fair warning!
I don’t know much about glue-ins – no time to wait for the glue to set.
Peter- I have a friend who has also been placing 1/4”ers from a stance and then rapping the route later to replace the 1/4”ers with 3/8” 5-piece. He says it works well.
Wish Rawl still made those 5/16” BHs...
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Dave Buchanan
Novice climber
Marin hot tub country, Ca
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Oct 17, 2002 - 06:46pm PT
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In response to Peter's question regarding the Ushba
Titanium glue-ins: (ushba.com)
They were used on Cantalope Death and Reg. Route
at pinnacles, and on the following routes at Mickey's
Beach -- all but Nancy done this spring:
Nancy (which also beefed up the anchor of Sex Porpoises
and Squid Vicious -- the're all shared)
Hot Tuna (all)
Motion In The Ocean (5)
Gidget meets the turgid seamonster (2)
Ocean Monster (3)
Sturgeon (added anchor bolt)
Scurvy (added anchor bolt)
Courtney (1)
Hundreds have been installed in Cayman Brac (Carribean)
and Thailand limestone without any failures thus far.
They are 80mm long and 10mm thick.
They require a 7/16 or 11mm SDS bit.
One thing that's nice about them is that the
round eyehole is roughly 1 1/2" -- plently
easy to clip -- or slip a couple fingers though
in desperate circumstances!
For the person who mentioned glue set up times:
Hilti C-100 and HY-150 (the 2 most popular in the US)
both gel in 3-4 minutes at 68 deg, and fully cure
in about an hour.
Hilti has great customer service and will answer
any technical questions you may have. (hilti.com)
Dave Buchanan
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