making wires on circuit board immobile but able to be removed later?...

[Chuck]

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?

 

[RD]

In article <rq3vhi$39f$1@dont-email.me>, chuck445@yahoonospam.com
says...

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

[snip]

Silicone. Lots of different brands & formulations
(RTV, Goop, etc.)

Dab a small bit on an unused corner of the board
and let it dry, to see if it can be peeled off
cleanly.

HTH

 

[tschw...@aol.com]

On Monday, November 30, 2020 at 6:00:11 PM UTC-6, RD wrote:

In article <rq3vhi$39f$1...@dont-email.me>, chuc...@yahoonospam.com
says...
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
[snip]

Silicone. Lots of different brands & formulations
(RTV, Goop, etc.)

Dab a small bit on an unused corner of the board
and let it dry, to see if it can be peeled off
cleanly.

HTH

Not great advice, as most silicones cure with acetic acid, which corrodes circuit boards.
If you must use silicone, use one that is specifically safe for electronics. There are only a few.

 

[Phil Allison]

tschw...@aol.com wrote:

=======================

Not great advice, as most silicones cure with acetic acid, which corrodes circuit boards.
If you must use silicone, use one that is specifically safe for electronics. There are only a few.

** Just get one labelled \" Neutral Cure \"

These are safe to use with metals like copper and tin.


...... Phil

 

[Phil Hobbs]

On 11/30/20 6:34 PM, 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?

Cyanoacrylate with accelerator. It sets fast, cracks off really easily
and can be cleaned up with acetone.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Arie de Muynck]

On 2020-12-01 00:34, 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?

Hot glue will soften when heated with a (controlled) heat gun, before
the electronics get damaged. Wires can easily be removed then.
Just experiment a bit on some old PCB.

Arie

 

[Peter W.]

From the literature:

3M 3748 Hot Melt Overview
The 3M 3748 is a unique hot melt adhesive often used in electronic assembly because it provides excellent thermal shock resistance and is non-corrosive to copper. The 3M 3748 also provides an excellent bond to polyolefins. The 3M 3748 also comes in a self-extinguishing version that meets UL 1410 requirements, 3M 3748VO.

Good stuff. And if you want to crack it off, a few minutes in the freezer makes it very easy to handle.

https://multimedia.3m.com/mws/media/1245163O/3m-hot-melt-adhesive-3764-3748-technical-data-sheet.pdf

Peter Wieck
Melrose Park, PA

 

[amdx]

On 12/1/2020 3:24 AM, Arie de Muynck wrote:

On 2020-12-01 00:34, 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?

Hot glue will soften when heated with a (controlled) heat gun, before
the electronics get damaged. Wires can easily be removed then.
Just experiment a bit on some old PCB.

Arie

And, use only enough to hold the wire, not so much that it is hard to
remove.

                                                     Mikek


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

[RD]

In article <7ef89ce5-fea8-4979-9d09-7fa15bff67d2n@googlegroups.com>,
tschw10117@aol.com says...

[snip]

Dab a small bit on an unused corner of the board
and let it dry, to see if it can be peeled off
cleanly.

HTH
Not great advice, as most silicones cure with acetic acid, which corrodes circuit boards.
If you must use silicone, use one that is specifically safe for electronics. There are only a few.

If you\'re gluing to a bare board and bare
traces that may be true, but it\'s rare to
find a board that isn\'t conformal coated
nowadays.

 

[Peter W.]

If you\'re gluing to a bare board and bare
traces that may be true, but it\'s rare to
find a board that isn\'t conformal coated
nowadays.

Conventional RTV silicones outgas acetic acid for some period up to days - long after it is \'cured\' for practical purposes. And that acetic acid will attack exposed metals of many types, including 304 and 316 stainless steel. And, worse, if that silicon is in a confined area such as an enclosed chassis, the damage could be inches away from the source.

Peter WIeck
Melrose Park, PA

 

[Adrian Caspersz]

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?

--
Adrian C

 

[Arie de Muynck]

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

 

[ohg...@gmail.com]

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.

 

[John Robertson]

On 2020/12/01 8:52 a.m., ohg...@gmail.com 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 :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John\'s Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
\"Old pinballers never die, they just flip out.\"

 

[John Robertson]

On 2020/12/01 9:29 a.m., John Robertson wrote:

On 2020/12/01 8:52 a.m., ohg...@gmail.com 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 :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John\'s Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
\"Old pinballers never die, they just flip out.\"

 

[Peter W.]

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.

Carnauba wax (plant-based) Beeswax and Paraffin wax all have their negatives.
Carnauba wax and Beeswax are both highly acidic, albeit with \'weak\' acids - but will attack bare copper and untinned copper wire over time. You will note that old waxed-paper caps used tinned copper or iron leads, not bare copper. You will also notice than when wax \'leaked\' onto the chassis, there would be a permanent stain on the chassis - from the acids in the wax. The mix on the old paper caps and coils was, typically, 80/20 paraffin to beeswax - the admixture was more stabile than either alone, and easier to work than either alone.
Paraffin wax oxidizes, is highly flammable - more so even than beeswax- and while hydrophobic is sufficiently lipophilic as to attract fat-based contaminants out of the air - such as cooking odors, nicotine and so forth.

Transformers back in the day were \'potted\' in either an asphalt-based tar (equivalent to modern non-plasticized hot roofing tar - that which is melted in tar-wagons), or in coal-tar pitch (awful stuff!). Both of which are stabile over a wide temperature range. Some few things were, in fact, potted in wax, but today that wax would be called \"Jeweler\'s Wax) which, when cold is machinable and quite hard.

There are \'archival\' waxes that are both acid free and self-extinguishing, but at $8 - $15 per ounce, not cheap.

I keep archival glue-sticks, electronics-safe glue sticks (compatible) and conventional glue-sticks (not compatible). I need two glue-guns as the change-over is quite wasteful otherwise.

Peter Wieck
Melrose Park, PA

 

[Allodoxaphobia]

On Mon, 30 Nov 2020 16:30:07 -0800 (PST), tschw...@aol.com wrote:

On Monday, November 30, 2020 at 6:00:11 PM UTC-6, RD wrote:
In article <rq3vhi$39f$1...@dont-email.me>, chuc...@yahoonospam.com
says...
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
[snip]

Silicone. Lots of different brands & formulations
(RTV, Goop, etc.)

Dab a small bit on an unused corner of the board
and let it dry, to see if it can be peeled off
cleanly.

Not great advice, as most silicones cure with acetic acid, which
corrodes circuit boards. If you must use silicone, use one that is
specifically safe for electronics. There are only a few.

.... specifically safe for electronics _and/or aquariums._

[Sorry - the first attempt went email...]
Jonesy
-- Marvin L Jones | Marvin | W3DHJ.net | linux
38.238N 104.547W | @ jonz.net | Jonesy | FreeBSD
* Killfiling google & XXXXbanter.com: jonz.net/ng.htm

 

[Chuck]

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., ohg...@gmail.com 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.

 

[Chuck]

On 12/1/20 12:40 PM, Peter W. wrote:

I keep archival glue-sticks, electronics-safe glue sticks (compatible) and conventional glue-sticks (not compatible). I need two glue-guns as the change-over is quite wasteful otherwise.

Peter Wieck
Melrose Park, PA

What would be wrong when using conventional glue sticks?

 

[Peter W.]

> What would be wrong when using conventional glue sticks?

Conventional glue-sticks have a much lower plastic temperature than the others - Anything lower than about 120 F should be fine. But understand that the melting point is about 175 F. Archival glue-sticks melt from 250 F to 380 F depending on the application. Electronics glue-sticks are designed for hot-temperature application or 350 F to 380 F. In a solid-state device with low voltages and (always) low ambient and operating temperatures, conventional glue-sticks should be fine unless labeled otherwise. Low-voltage unless the sticks carry a UL-94 listing.

Peter Wieck
Melrose Park, PA