Towertalk
[Top] [All Lists]

Re: [TowerTalk] Tower base

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Tower base
From: Jim Lux <jimlux@earthlink.net>
Date: Sat, 04 Jan 2014 09:00:20 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On 1/4/14 8:47 AM, Ray, W4BYG wrote:
When drilling into concrete or stone for mounting bolts, I many years ago
learned a neat trick from an old time machinist, Grover Shank.  He advised
me concrete injected around bolts or hardware store expansion devices will
vibrate and eventually come loose.



I understand that they used to set parking meters with sulfur..When the meter was damaged, they could replace it by melting out the sulfur.

These days, one uses epoxy as a "chemical anchor". The epoxy is specifically designed to have the right amount of resilience to avoid cracks, etc.

BTW, silicon, germanium, gallium, Antimony, and Bismuth expand when solidfying. I don't know that sulfur does. Iron might also (I found several references with varying density numbers. it's a pretty close thing).

It has to do with whether the crystal lattice is spaced farther apart than the atoms in liquid. There's a bunch of compounds that expand on freezing: most salts, acetic acid, but not sulfuric or nitric acid (something to keep in mind when you're making your own blasting supplies for that really tough rock)

(not that pouring molten silicon to hold in a bolt is something you're likely to be doing..<grin>)

Sulfur, though, is an example of something that forms an amorphous non-crystalline solid (like glass). However, I seem to recall from 40 years ago that a lump of molten sulfur that is cast eventually turns into powdered sulfur. But maybe there's some annealing or heat profile that's important.
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>