Towertalk
[Top] [All Lists]

Re: [TowerTalk] A couple of 18HT questions

To: towertalk@contesting.com
Subject: Re: [TowerTalk] A couple of 18HT questions
From: Jim Lux <jimlux@earthlink.net>
Date: Wed, 17 Dec 2014 11:47:08 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On 12/17/14, 11:16 AM, Gary Schafer wrote:
Hi Allen,

You do not want concrete in contact with aluminum! It will eat up the
aluminum. Even aluminum windows come with a warning to not let the brick
mortar come in contact with the aluminum frame when installing.
After the concrete is set and dried it may be ok then, not sure.

73

Yes indeed.. Aluminum is readily attacked by most acids and bases: the surface oxide helps a lot, and, of course, a chemical conversion coating (anodize, alodine) would too. BUT, a scratch in the coating provides a nice surface to be attacked.

ALuminum is attacked by most basic hydroxides (e.g. sodium hydroxide, lye, is used to etch aluminum panels).. It is a way to make hydrogen gas, in fact.

Mortar is a mixture of quicklime (CaO) and sand, for the most part, and when you add water to it (slaking the lime) it forms Calcium Hydroxide (Ca (OH)2).

Concrete has similar chemistry.

So, yes.. keep your aluminum out of the concrete footing.

_______________________________________________



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

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