Hello Colleagues & Friends,
Just my .02 worth. Thread locking, including Loctite, is a tricky
subject. In my opinion, the Newton Meter (or whatever you use) torque
and sequence of tightening is one of the most important aspects of
thread tightening and holding. When heat is applied to release a screw
that is filmed with thread locker, there is a risk of changing the
temper of the metallic parts involved. Not a good thing. Over the years,
I have seen many 6 mm hex head screws stuck to a point that the hex is
stripped because the wrong thread locker was used, even when a good hex
tool, such as Parke, is used. When that happens, a center punch and
hammer is often the best solution for releasing the screw. Of course the
screw is damaged, but those are normally replaceable. Screws can also be
burned out without consequence with some expensive arcing equipment. How
much heat goes to the surrounding parts, I do not know. But I’ve never
seen a screw that could not be burned out successfully. So my thoughts
are that if you are using Loctite red, it is very likely that heat (or a
center punch) will be needed to release some 6mm pyramid screws. That is
not a practical solution for parts that need to be released and
re-tightened during adjustments. To muddy the water a bit more, the
Permatex manufacturer, suggests red for 10-25mm threads. I think
Loctite is likely more or less in agreement with this as well. As such,
I believe this would be a good topic for a student research project.
Maybe we could all learn something. Reading the manufacturer’s data
sheets will likely only confuse, so the summary of a research story may
be; what works, what doesn’t, why, and what is the correct procedure
involved. Did I mention the incompatibility between unlike metals? There
is another research project. Finally, are the component thread hole
angles matched to the pyramid? Is there an agreed upon angle standard
for the pyramid and associated components? In the past, I know this was
not always so, but I am not aware of the manufacturing standards
regarding this today.
In the meantime, perhaps one or more of the industry engineers could
chime in.
As we get older, some of us tend to dig deeper and
deeper…………………..until. And of course, some of us have been
digging deep for a long long time.
Thanks to Jim Young for bringing this matter up. I think Loctite and the
loose pyramid is a problem that deserves some discussion.
Regards,
Wil Haines, CPO
On 10/24/2016 11:47 AM, Jim Young Cp Faaop wrote:
> I have had several issues where the Kinterra pyramid bolt coming loose. The
> mfg claims that they have only had one report of that happening, but I
> have reported loose bolts on at least four different occasions. Am I the only
> one? I now replace the factory blue removable loc-tite, with the red
> loc-tite and have not had a problem since.
>
>
>
> SGT. James O. Young Jr., USAF (ret.), B.Sc., LP, CP, FAAOP
> AMPUTEE PROSTHETIC CLINIC
> Macon Tifton Albany
> 888FAKELEG
> 888fakeleg.com
>
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