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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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making wires on circuit board immobile but able to be removed later?
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? |
#2
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making wires on circuit board immobile but able to be removed later?
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#3
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making wires on circuit board immobile but able to be removed later?
On Monday, November 30, 2020 at 6:00:11 PM UTC-6, RD wrote:
In article , 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. |
#4
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making wires on circuit board immobile but able to be removed later?
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 |
#5
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making wires on circuit board immobile but able to be removedlater?
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.Â* 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.Â* 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 |
#6
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making wires on circuit board immobile but able to be removedlater?
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.Â* 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.Â* 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 |
#7
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making wires on circuit board immobile but able to be removed later?
From the literatu
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/...data-sheet.pdf Peter Wieck Melrose Park, PA |
#8
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making wires on circuit board immobile but able to be removedlater?
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.Â* 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.Â* 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. Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Â*Â* Mikek -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
#9
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making wires on circuit board immobile but able to be removed later?
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#10
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making wires on circuit board immobile but able to be removed later?
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 |
#11
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making wires on circuit board immobile but able to be removed later?
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.Â* 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.Â* 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 |
#12
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making wires on circuit board immobile but able to be removedlater?
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.Â* 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.Â* 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 |
#13
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making wires on circuit board immobile but able to be removed later?
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. |
#14
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making wires on circuit board immobile but able to be removedlater?
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 :-#)# -- (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." |
#15
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making wires on circuit board immobile but able to be removedlater?
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,Â* capacitors, transformers, etc. were potted in wax for decades without issues.Â* 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." |
#16
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making wires on circuit board immobile but able to be removed later?
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 |
#17
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making wires on circuit board immobile but able to be removedlater?
On Mon, 30 Nov 2020 16:30:07 -0800 (PST), wrote:
On Monday, November 30, 2020 at 6:00:11 PM UTC-6, RD wrote: In article , 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 |
#18
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making wires on circuit board immobile but able to be removedlater?
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,Â* capacitors, transformers, etc. were potted in wax for decades without issues.Â* 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. |
#19
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making wires on circuit board immobile but able to be removedlater?
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? |
#20
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making wires on circuit board immobile but able to be removed later?
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 |
#21
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making wires on circuit board immobile but able to be removedlater?
On 12/1/20 2:11 PM, Peter W. wrote:
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 Ok, thanks because I wasn't sure. That part of the circuit won't be under heating so I'm going to go ahead and use the sticks I have. |
#22
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making wires on circuit board immobile but able to be removedlater?
On 12/1/20 1:32 PM, 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,Â* capacitors, transformers, etc. were potted in wax for decades without issues.Â* 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.Â* 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.Â* The design is not mine, but uses two auto HEI coils in opposite phase.Â* To get the voltages needed and not destroy the coils, they had to be placed under oil.Â* 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.Â* 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.Â* I did this last year.Â* 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.Â* 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.Â* 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!Â* I have another homemade device, a high voltage probe, consisting of many resistors in series.Â* It can measure up to 100 KV and uses a standard multimeter with its very high resistance.Â* I made it 20 years ago.Â* 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.Â* 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.Â* I then knew for sure that it was oil.Â* 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.Â* Well, although I sealed around the wire to PVC exit, I didn't properly seal the strands themselves.Â* It took 19 years, but oil made its way through that wire and was dripping from the end plugged into the meter.Â* It's not much, maybe five drops in several months, but definitely a leak.Â* 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.Â* 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.Â* 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.Â* I just have to be sure not to get any of the glue on the soldered traces themselves. Incidentally, to follow up a bit, I concluded that the reason why the original oil container leaked was due to thermal expansion of the oil through the container. The coil containment container was sealed with gaskets (at the top only) and I think the oil pushed through the gaskets when temperatures in the environment were higher. Not sure, but the real test this time will prove/ disprove this as I refilled with oil but leaving space between the oil and top/ gasket seal. |
#23
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making wires on circuit board immobile but able to be removed later?
On Tuesday, December 1, 2020 at 12:31:31 PM UTC-5, John Robertson wrote:
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 :-#)# Hard waxes generally contain acids. |
#24
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making wires on circuit board immobile but able to be removed later?
On Mon, 30 Nov 2020 18:34:09 -0500, Chuck
wrote: 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. Hot glue will release nicely with a drop of isopropyl alcohol. |
#25
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making wires on circuit board immobile but able to be removed later?
Phil Allison wrote:
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 I tried some on copper once to test. If anything acid cleans copper. After evaporation no action exists, which is minimal time. Greg. |
#26
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making wires on circuit board immobile but able to be removed later?
RD wrote:
In article , 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 Goop is very strong stuff, hard to remove. Greg |
#27
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making wires on circuit board immobile but able to be removed later?
On Monday, November 30, 2020 at 7:00:11 PM UTC-5, RD wrote:
In article , 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 Look at Dow Chemical for silicon based products that are safe for electronics...I used some of their products in a similar application many many moons ago...damn if I can remember the product numbers... J |
#28
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making wires on circuit board immobile but able to be removed later?
In article ,
three_jeeps wrote: Look at Dow Chemical for silicon based products that are safe for electronics...I used some of their products in a similar application many many moons ago...damn if I can remember the product numbers... Dow 3145 is one such. You won't like the price very much, but it's MIL-spec'ed for this sort of purpose. Dow's Dowsil 737 is a neutral-cure which seems of a similar nature - not a MIL-spec reference, but it's much more affordable. |
#29
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making wires on circuit board immobile but able to be removed later?
On Thursday, December 10, 2020 at 1:59:02 AM UTC-5, GS wrote:
RD wrote: In article , 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 Goop is very strong stuff, hard to remove. I'm now wondering if liquid nails is a neutral cure or not. I guess I've used it with pot metal or the metal of the side of a panel (not significant). |
#30
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making wires on circuit board immobile but able to be removed later?
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. |
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