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Re: [TowerTalk] Anchor bolts for LM470

To: "'K8RI'" <>, <>
Subject: Re: [TowerTalk] Anchor bolts for LM470
From: "Mike Baker" <>
Date: Sun, 15 Apr 2012 22:19:35 -0700
List-post: <">>
It is not necessary to coat the anchor bolts with anything.
When the steel is encased in concrete it cuts of the supply of Oxygen so it
doesn't rust. If steel rusted inside concrete you would have to galvanize
Use of an extension type concrete vibrator while doing the pour will spread
it out and settle any air pockets out of it.  If you just place the vibrator
on the side or top of the bolt when installed for a few seconds it will
settle the mix around the bolt quite nicely and keep out the air pockets.
That is a worse case scenario. 

Mike Baker  K7DD
All QSO's are uploaded to LOTW and EQSL.

-----Original Message-----
[] On Behalf Of K8RI
Sent: Sunday, April 15, 2012 9:45 PM
Subject: Re: [TowerTalk] Anchor bolts for LM470

On 4/15/2012 10:39 PM, Mike wrote:
> Dave,
> That's what I was thinking as well.  I have seen people cut off and 
> weld the three LM-470 bolt Ears to a US-Towers "T-Base" which works, 
> but I do not understand what this is about.

"My thoughts!":

The bolt head, J, flag, or plate only needs to be big enough to prevent the
anchor from turning, pulling out, or over stressing that small area of
concrete.  I think J-bolts are by far the cheapest and easiest to make if
you do-it-yourself.

As for "All Thread" which is plain old threaded rod, isn't it a bit soft to
use? I've never seen it except in ungraded strength.  I've been planning on
using 1" or 1.25" bolts, 3 feet (give or take and boy are they heavy!) long
with a 1/4" X 6 X 6 or even 4 X 4 flat plate welded on the bottom and a
couple of 1/4" thick ears welded on the sides at the base for my projects.
The thing about hard bolts is they rust more easily so they have to be
protected. You can also tape the threaded portion that goes through the
base. I'll be using a separate base so the plans call for the bolts to be
installed in the base which will then be lowered over the hole.  The base
needs to be leveled and secure  before the concrete is poured and care used
to completely encase the bolt heads in concrete with no voids.  Protect the
threads to allow for re leveling the base and removing the base after the
concrete has cured. Use Tape, Saran Wrap(TM) or what ever comes to mind.
Then warm them up to about 50C and liberally coat them with thinned tar. If
necessary recoat with tar about twice as thick as the original coat.  If the
bolts are clean, dry, and fairly warm (or hot) the tar will uniformly adhere
and not come off.  it stinks but it works. Also you can get the nuts off if
you ever need to. Just don't heat them enough to take the temper out which
is really hot.

Undoubtedly there are others on here who have alternate methods of
protecting the base hold down bolts.


Roger (K8RI)
> Mike, K6BR
> -----Original Message-----
> From: 
> [] On Behalf Of Dave 
> Hachadorian
> Sent: Sunday, April 15, 2012 7:29 PM
> To: Towertalk reflector
> Subject: Re: [TowerTalk] Anchor bolts for LM470
> So how are you guys using anchor bolts on an LM470?  Has someone 
> designed an
> LM470 mounting plate that fits on anchor bolts?
> Normally the LM470 mounts on a special base section that is buried in 
> concrete.  If you want to move the tower, you have to buy another base 
> section from the factory.  What are you guys talking about?
> Dave Hachadorian, K6LL
> Yuma, Arizona
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