[Elecraft] Problem with a K3 screw

[Fred Townsend]

Gentlemen: 
I have my doubts about acetone being used in nail polish but it's possible
some manufacturers are using it to cheapen their products. It's a poor
solvent for this purpose. However there is no doubt acetone is used in
almost every nail polish remover. I keep some in the medical cabinet to
unstick fingers bonded together with crazy glue. That being said acetone
should never be anywhere near any electronics. I have shut down production
lines because someone snuck acetone onto the line for cleaning. It doesn't
have to come in contact to damage plastics and other encapsulating materials
used for electronic parts. The vapors are enough to cause latent defects
that may take years to mature. It particularly damages polystyrene used in
some high stability capacitors. Wonder why your VFO drifts? It may be
because someone used acetone on it years before. If you must use a solvent
for cleaning, say flux, use isopropyl alcohol. 

Loctite is corrosive. Read the label. It is not recommended for some metals
or plastics. If you most use Loctite in electronics use the blue (mild)
colored product. Some Loctite is used for chemical welding and can never be
undone.

Glyptal is the favorite of the military, Collins, and FAA. However xylene
has been banned in electronics in many countries. Ever heard of glue
sniffing zombies? It does brain damage and it's a mild carcinogen. There may
be a xylene free Glyptal out there; I don't know. My bottle is 50 years old.
A little dab will do you if you keep the cap on tight.

None chemical means such as the formally mentioned Nyloc nuts or mechanical
locking hardware is the preferred technic for locking parts and they don't
void your warranty. (See Eric's earlier post on corrosionX.) 
73
Fred, AE6QL

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Ron D'Eau Claire
Sent: Friday, December 28, 2012 5:37 PM
To: k2asp at kanafi.org; 'Elecraft'
Subject: Re: [Elecraft] Problem with a K3 screw

Fingernail polish uses acetone which, of course, will soften *some*
plastics, but unlike the solvent in Loctite, acetone evaporates completely
and the end result is quick-drying, chemically stable coating. 

Of course there is always Glyptal which uses xylene for its solvent. That,
too, will soften some plastics. But it, too, dries to a chemically stable
state, unlike Loctite.

I don't know what Loctite uses. 

73 Ron AC7AC

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Phil Kane
Sent: Friday, December 28, 2012 3:42 PM
To: Elecraft
Subject: Re: [Elecraft] Problem with a K3 screw

On 12/28/2012 11:08 AM, Ron D'Eau Claire wrote:

> Instead I borrow a trick from my post WWII aircraft service days:
> paint. A drop of fingernail polish between the nut what it tightens 
> against works very well. If you don't want it visible, paint the 
> threads with some and then put the nut on over it, or paint the face 
> of the nut that presses against the fan with black fingernail polish 
> (a common color nowadays :-) and screw it in place before it dries.
> 
> It's not so strong that you can't remove the nut, but it should 
> prevent loosening due to fan vibration.
> 
> And then there's always lock washers.

How much and what type of solvent does the fingernail polish carry as
compared to LockTite?

My preferred solution is to use nylon-insert stop nuts, which I learned
about when I worked at the Douglas Airplane Works for a brief time.  The
local ACE Hardware outlet carries them in all sizes.

73 de K2ASP - Phil Kane
Elecraft K2/100   s/n 5402


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