On Tuesday, December 1, 2020 at 1:32:58 PM UTC-5, Chuck wrote:
On 12/1/20 12:31 PM, John Robertson wrote:
On 2020/12/01 9:29 a.m., John Robertson wrote:
On 2020/12/01 8:52 a.m., wrote:
On Tuesday, December 1, 2020 at 11:20:44 AM UTC-5, Arie de Muynck wrote:
On 2020-12-01 15:58, Adrian Caspersz wrote:
On 30/11/2020 23:34, Chuck wrote:
I am in the process of modifying a circuit by adding a small external
circuit board and then wiring into the main board. I don't want the
wires to move around when I'm done, but yet if I ever need to make
repairs, I want to be able to remove them. I see some people using
hot glue for such matters, but I don't think I'd be able to desolder
the wires later without using a lot of force to remove the hot glue
first. What could I use?

Candle wax?

NO!
Long ago (50+ years) I used that to stabilize selfwound RF inductors..
The copper rotted away within a year. It may depend on the wax type,
bees wax is supposed to be less agressive.

Arie

I would think that candle wax would have dyes and perfumes added.
Lots of coils, capacitors, transformers, etc. were potted in wax for
decades without issues. I guess pure beeswax would be the safe bet
though.


I use beeswax for repotting some 1970s flybacks on old GE TVs that we
use in some classic video games made by Nutting Assoc. Works great and
hasn't led to any further trouble after upwards of ten years...I made
a simple silicon mold to hold the old core and just warm up and pour
the wax in.

John :-#)#


I should add that beeswax is likely too soft to hold the wire suspended
for any period of time and it melts at lowish temps, it would probably
be of no use to the OP for his application.

John :-#)#

Interesting. Not to change my own topic here, but I have a 125 KV high
voltage generator that I made myself fifteen years ago for
demonstrational purposes. The design is not mine, but uses two auto HEI
coils in opposite phase. To get the voltages needed and not destroy the
coils, they had to be placed under oil. However.....

Three years ago, after the device had been stored away for almost a
decade, I removed it and its storage container (I always keep any oiled
components in an extra container to contain possible leakage later).
Well, good thing I had the extra container as there was some leakage.
Not much, but enough that I decided to drain and switch out containers.
Done and restored.

Another option at the time of the original build was, instead of using
oil, to place the coils in wax. I never did this originally, but
decided to make a spare HV section (which only contains the two coils).
This time, I used white canning wax with no additives. I did this last
year. The year before, I was worried that the canning wax might crack
upon exposure to heat and cool, so I poured a block and placed it into
an environment with a lot of temperature extremes for a year. No
cracking after a year, so that's when I decided to pour the wax spare
generator section.

Now, just as a precaution, I'd never take the unit in a hot car, warmed
up from summer heat let's say, for any length of time as I'd be
concerned that the wax might start melting, so that's where the oil
filled one would be used. Where the wax one is stored might vary from
15-100 F, so confident at those temps.

Oil can sure creep right through and out of things! I have another
homemade device, a high voltage probe, consisting of many resistors in
series. It can measure up to 100 KV and uses a standard multimeter with
its very high resistance. I made it 20 years ago. However, being
stored on the shelf above me right near where I sit here, I noticed some
suspicious spots of what I thought was water at first on the rug this
past summer. I was perplexed at first and thought my roof might be
leaking until I decided to finger the wet drop one day and rub fingers
together to see if it was in fact water. I then knew for sure that it
was oil. Turns out that when I made my HV probe, I exited the resistor
PVC enclosure with a piece of HV multi-stranded TV wire of the kind
often seen coming out of TV flybacks. Well, although I sealed around
the wire to PVC exit, I didn't properly seal the strands themselves. It
took 19 years, but oil made its way through that wire and was dripping
from the end plugged into the meter. It's not much, maybe five drops in
several months, but definitely a leak. Not having time to get to this
yet to remedy, I covered over the wire end with a plastic bag and had
this hang out over the shelf side to contain any further leaking. As of
today, the bag probably contains an ounce of oil.

As for the circuit board, I probably won't use wax to hold the wires. I
like the hot glue idea, which I have in abundance here, and I can always
reheat later to the wires come right back off the board. I just have to
be sure not to get any of the glue on the soldered traces themselves.

I'm sure that the container makes and oil in pole pigs won't have such a leak problem as your home spun contraption. Not to say that hauling a decommissioned transformer, capacitor or inductor from off of a telephone pole into your garage for emptying is a good idea, either.