Author Topic: Big Wall Bolting--the art of quarter inch  (Read 397 times)

Deuce

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Big Wall Bolting--the art of quarter inch
« on: September 18, 2019, 07:23:53 PM »
Until about the late 80's, 1/4" Rawl split shank bolts were the standard for all climbing. 

1/4" bolts are reasonably safe for the kind of use where they don't get used much (I.e. most types of climbing except sport).

They are still vital tools for remote expeditionary big wall climbs, where hand drilling is the only option, and fast and light is the name of the game.

It seems the art of 1/4" drilling has been largely lost.  There are only a few tools available for optimal (I.e. short) 1/4" drills, the Hurricane Mountain Works drill (which also can be used for 3/8" bolts for sandstone walls), available from Runout Customs, is one of the only options.  Dammerr also makes a nice shorty emergency 1/4" kit.  Using stock SDS is problematic, as the drills are usually too long for decent on stance drilling, also they have a carbide tip better suited to the repeated crushing impact of a rotary hammer drill as opposed to the slowly rotating chiselling which happens when hand drilling. 

Below is a "treatise" on drilling I wrote in the 80's. A lot of the info is outdated, but there still are some valid info for those wanting to make an expeditionary bolt kit. There's both the published version (with test results) and the initial draft I wrote in those pre-computer days.

Feel free to discuss, and hopefully chime in with relevant info about drilling fast and light on big walls and runout backcountry stance drilling.
« Last Edit: September 18, 2019, 07:25:51 PM by Deuce »