Re: False sense of security, thread locker

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "D.C. Cox" <resonance@xxxxxxxxxx>


For rotary sparkgaps press the 1/2 dia. x 1.5 inch long brass rod 
axially thru the G-10 by having a machine shop do it.  They use a 
precision reamer than reams .0005" undersize and then the press fit 
using an arbor press is very tight.  They just will not come loose at 
power levels up to 25 kVA.  We then use 3/8-16 NC threaded 
tungsten-moly alloy electrodes that just screw into the brass using 
one drop of threadlocker.

To get the absolute precision and safety a good machinist has to do 
the work.  It's just not possible for the home hobbyist to achieve 
this precision on these safety critical parts.

Dr. Resonance




Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>

Hello All,

Through my own stupidity I applied 710 loctite
thread locker(red) to my set screws on my 12 "
rsg and twenty four hours later tried to break em
loose for better adjustments. I usually use the
blue on my motor cycle. Well needless to say I
was twisting allen wrenches into miniature wrought iron gates.

Then I went to their web site and discovered a
surprise. It liquefies at 250 C (450 F), I broke
out my circuit board iron (just kidding) a Weller
140watt gun. Appling heat to the longish set
screw liquefied the thread locker very well thank you.

Now this is a bit disturbing as the set screw is
holding the tungsten. My experiment allowed me to
twist the set screw at half that temperature
although I don't have a thermal couple.

Now the clincher. I'm only using set screws on
one side of my g10 through the allthread and
brass nut method the other side is securely
torqued down and double so with the new red paste
stick, nice stuff except for one caveavat: it
liquefies at 150 C (300 F) almost lubricates.

Weren't we just talking about flying tungsten?
Would any of you material engineers out there
like to offer a more suitable alternative?

Long Sparks and Secure nuts,
Jim Mora