http://www.mtu.edu/materials/k12/experiments/creep/
the link got all the parameters and theory...
On Nov 15, 2017, at 9:50 AM, George Wenger wrote:

> Sorry.  It was so long ago I don't remember what diameter solder  
> wire he used.
>
> -----Original Message-----
> From: Stadem, Richard D [mailto:[log in to unmask]]
> Sent: Wednesday, November 15, 2017 9:43 AM
> To: TechNet E-Mail Forum <[log in to unmask]>; George Wenger  
> <[log in to unmask]>
> Subject: RE: [TN] Question on Loading Solder Joints
>
> I wonder what diameter of solder is most useful to demonstrate the  
> property within two or three hours, and with what weight?
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of George Wenger
> Sent: Tuesday, November 14, 2017 4:42 PM
> To: [log in to unmask]
> Subject: Re: [TN] Question on Loading Solder Joints
>
> I'm about to go out to dinner with my youngest son and my two  
> youngest grandsons otherwise I would be downstairs in my work shop  
> hanging weights.  What I would like to do is hang three solder  
> wires (1ft, 2ft, and 3ft) and time the creep elongation for each.   
> I'm pretty sure the weight used by the teacher was a 1Kg weight.
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman
> Sent: Tuesday, November 14, 2017 5:37 PM
> To: [log in to unmask]
> Subject: Re: [TN] Question on Loading Solder Joints
>
> LOL - I have the "test" in progress in my office right now - but  
> the solder wire length is one one foot long!
>
> Dave
>
> On Tue, Nov 14, 2017 at 4:31 PM, George Wenger  
> <[log in to unmask]>
> wrote:
>
>> Richard,
>>
>> Although I have a good analytical mind and remember this  
>> demonstration
>> very well I may have not gotten the dimension exact.  The more I  
>> think
>> about it I think the blackboard was 4 ft tall and the solder wire may
>> have only been 2.5 to 3 ft long and the class was all morning
>> (9:00am-11:30) so the solder wire broke before the class was over so
>> it might have broken closer to two hours then one hour.   
>> Nevertheless, the demo made its point.
>>
>> George
>>
>> -----Original Message-----
>> From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D
>> Sent: Tuesday, November 14, 2017 5:21 PM
>> To: [log in to unmask]
>> Subject: Re: [TN] Question on Loading Solder Joints
>>
>> I can just hear Bev cutting the 4 ft section of wire solder as I  
>> write
>> this.......LOL!
>>
>> -----Original Message-----
>> From: TechNet [mailto:[log in to unmask]] On Behalf Of BEV CHRISTIAN
>> Sent: Tuesday, November 14, 2017 3:37 PM
>> To: [log in to unmask]
>> Subject: Re: [TN] Question on Loading Solder Joints
>>
>> George, Ioan and Dave.
>> Thx!
>>
>> Regards,
>> Bev
>>
>> Sent from Mail for Windows 10
>>
>> From: George Wenger
>> Sent: Tuesday, November 14, 2017 4:00 PM
>> To: 'Bev Christian'
>> Cc: 'TechNet E-Mail Forum'; 'David Hillman'
>> Subject: RE: [TN] Question on Loading Solder Joints
>>
>> Bev,
>>
>> I'm really an old timer with lots of practical experience and I can
>> remember back in the early 70's taking a class at The Western  
>> Electric
>> Corporate Education Center in Hopewell NJ and the teach said that you
>> should never have a solder joint under a tensile load.  He continued
>> to say that rather than give you a 1000 words to tell you why not  
>> that
>> he would show us a very simple and very graphic demonstration.  He
>> pulled a roll of solid solder wire out of his desk and said it was
>> Sn60 but it really didn't matter what the solder alloy was.  He cut
>> off a 4 foot length of the solder wire and tied one end to a hook at
>> the top of the blackboard and then tied a weight to the other end of
>> solder wire.  He took a chalk and marked a line on the blackboard  
>> just
>> where the bottom of the weight was.  He then continued teaching the
>> days lesson but every 15 minutes of class, without saying  
>> anything, he
>> would take the chalk and mark where the bottom of the weight was.
>> After about a little over an hour, while he was busy instructing  
>> us on
>> the days lesson, we heard a loud "bang".  The solder wire had
>> continued to elongate while it was under the tensile load of the
>> weight and finally the solder wire broke approximately in the  
>> middle and the weight dropped onto the floor.  Right after every  
>> one heard the loud "bang'
>> of the weight hitting the floor he stopped what he was talking about
>> and simply said "that is why you never what a solder joint to be
>> subjected to a continuous tensile load".  Although it's been  
>> almost 45
>> years since I attended that class I'll never forget what he said.
>>
>> George
>>
>> -----Original Message-----
>> From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman
>> Sent: Tuesday, November 14, 2017 3:33 PM
>> To: [log in to unmask]
>> Subject: Re: [TN] Question on Loading Solder Joints
>>
>> Hi Bev - I would point them to RJ Klein Wassink's book "Soldering In
>> Electronics", ISBN 0-901150-24. In the Mechanical Properties Section
>> 8.4 it states "From the data in section 4.7.2 it is obvious that a
>> normal soldered connection on a printed board is not well suited to
>> withstanding a permanent mechanical load."
>>
>> And in Section 4.7.2 Creep, there is some good data on the creep
>> properties of solder backing up that statement.
>>
>> Dave Hillman
>> Rockwell Collins
>> [log in to unmask]
>>
>> On Tue, Nov 14, 2017 at 2:12 PM, BEV CHRISTIAN
>> <[log in to unmask]
>>>
>> wrote:
>>
>>> TechNetters,
>>> A fellow ex-BlackBerry employee sent me the following query. I
>>> obviously no longer have access ot the search capabilities I had at
>>> BB.  Can anyone offer any suggestions for papers that will meet his
>>> needs?  I mean I know the reason why, but he wants a paper that
>>> proves
>> it.
>>>
>>> I need help with locating a couple of good papers and research
>>> studies that explain why designs that place a constant tensile or
>>> shear load on board connectors(USB, HDMI, RCA, AC inlet etc.) are a
>>> bad idea. Can you point me to a couple of papers on this ? Thanks.
>>>
>>> Regards,
>>> Bev
>>>
>>> Sent from Mail for Windows 10
>>>
>>