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Re: [TowerTalk] Seized mast clamp bolts Hy-gain 10 meter yagi

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Seized mast clamp bolts Hy-gain 10 meter yagi
From: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Reply-to: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Mon, 4 Jan 2010 10:43:26 +0000
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Roger (K8RI) wrote:
>
>
>Ian White GM3SEK wrote:
>>>
>>
>> I've never felt comfortable about using oil- or grease-based materials
>> on threads that are supposed to stay tight afterwards.
>>
>> A lesser-known feature of Loctite and similar thread locking fluids is
>> that they also prevent galling when the nuts are being tightened. I've
>> always had good success with the "blue" Loctite grades like 242 which
>> are designed to be released with hand tools. SS nuts tighten up smoothly
>> and the galling doesn't happen.
>>
>>
>I believe you will find that even the so called permanent Loctite, will
>cleanly release with a bit of heat.
>

The grades of Loctite are roughly color-coded into:

•• Low strength (purple aka pink): Easy disassembly using hand tools
[Used by clock and instrument makers for tiny screws.]

•• Medium strength (blue): Disassembly possible with standard hand 
tools.
[Good for almost any antenna/tower application. 243 looks like their 
currently preferred general-purpose grade, and a small bottle lasts a 
very long time. The new 248 'lipstick' applicator looks very handy to 
use.]

•• High strength (red): Requires localized heat (>500°F), hand 
tools and disassembly while still hot.
[These are the so-called permanent grades. Disassembly might be tricky, 
up the tower...]

For more details, see:
<http://www.henkelna.com/us/content_data/138230_LT4985TLCapabilityGd.pdf> 
or <http://tinyurl.com/yesv9sb>

This leaflet also mentions prevention of galling when nuts or bolts are 
being tightened.


>However if the proper torque is achieved with neverseize the nuts will
>not come loose. OTOH a nut installed to 100' lbs with never seize on the
>threads exerts *far* more pressure on the bolt than does one torqued
>down the the same numbers dry.
>
A very good point.


-- 

73 from Ian GM3SEK
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