[TowerTalk] Anchor bolt material

[Ray, W4BYG]

While I don't have detailed specifications, I know from experience 
heating drug store sulphur to a liquid and pouring it into such holds 
provides an extremely strong bond to the the bolts and concrete.   As 
the molten sulphur cools, it expands and locks into the hole and around 
the bolt.

The process is quite easy although smelly, during the heating.  I used 
an inexpensive  smelting pot and a butane torch.  The result was an very 
good bond for guy anchors holding up a 70' tower with a Mosley S-402 40 
meter beam on top and a CL-36 tribander, 15' below.    The cost is 
virtually nothing.

I was clued into this by an old time professional machinist who told me 
this was how they locked heavy, vibrating, machinery down.  They never 
had a failure, nor did I.
Ray, W4BYG


On 10/12/2014 12:30 PM, Mickey Baker wrote:
> You're asking for engineering analysis of a non-standard scenario. Any
> advice would be risky.
>
> 1.125" bolts in a 2.5" diameter hole leaves a lot of space for fill. It
> appears to me that you'd want to use a structural epoxy like Strong Tie,
> but their data sheets don't cover this situation. I am using 1.125"
> threaded rod in a 1.25" hole with Strong Tie... It will consume less than
> two 22 ounce tubes. Your situation would use about 6 of those, but may not
> be strong enough, I don't know. Cost is $30+ per tube! and you need the
> mixing nozzle and a two part dispenser if you're doing it yourself.
>
> Concrete mixes probably don't provide enough adhesive strength to prevent
> pull out at load. Again, that's an estimate, not a certainty. I wouldn't do
> it for my tower.
>
> Do what you will, you're into a custom engineering situation. In my
> estimation, you need smaller holes or lots of structural epoxy.
>
> I'd hire an engineer with experience in customized use of structural
> adhesives. Or maybe someone here has that experience and can shoot from the
> hip.
>
> I'd get a professional opinion and put the project off a week. Better safe
> than not.
>
> 73,
>
> Mickey N4MB
>
> On Sunday, October 12, 2014, Marvin Shelton <marvs at att.net> wrote:
>
>> Here’s a question for everyone. I’m installing a new T-base for my
>> crank-up US Tower so that I can use the raising fixture and stop climbing
>> it when it’s retracted. (getting too old for that) and I’ve got the holes
>> prepared and am wondering about the anchoring material to use.
>> I’ve drilled the holes 2.5” in diameter to account for the nuts at the
>> base of the anchor bolts, which I’ve had to cut off because I couldn’t go
>> deep enough. So now I have 2.5” diameter holes to install 1-1/8” anchor
>> bolts in.
>>
>> My obvious choices are anchoring epoxy, which is expensive at over $20 per
>> tube, Quikrete anchoring cement, and I just discovered something called
>> Rockite- for anchoring and patching.  I’m hoping that any of these choices
>> will work. I’d like to save a few $$ and use the Quikrete which will be
>> much easier to use (mix like concrete and pour into the holes). It has a
>> pull-out strength of 14,100 psi  after 24 hours and 21,000 psi after 28
>> days.
>>
>> Anyone have experience with any of these products. I’d like to do my pour
>> today if possible.
>>
>> Thanks in advance.
>>
>>
>> Marv
>> wa2bfw at arrl.net <javascript:;>
>>
>>
>>
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-- 
Ironic:
The food stamp program, part of the Department of Agriculture, is pleased to be distributing the greatest amount of food stamps ever.
Meanwhile, the Park Service, also part of the Department of Agriculture, asks us to "please do not feed the animals" because the
animals may grow dependent and not learn to take care of themselves...  (Think about that).