• Concerns when "potting" components in cement/mortar/concrete

    From Don Y@3:633/10 to All on Sunday, May 31, 2026 07:16:49
    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of? Is there significant expansion
    (or shrinkage) during curing?

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From joegwinn@3:633/10 to All on Sunday, May 31, 2026 10:20:06
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of? Is there significant expansion
    (or shrinkage) during curing?

    Even dry-seeming concrete is a reasonably good electrical conductor - implements a resistor.

    Joe

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From john larkin@3:633/10 to All on Sunday, May 31, 2026 08:44:54
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of? Is there significant expansion
    (or shrinkage) during curing?

    Most people use polyurethane or epoxy.


    John Larkin
    Highland Tech Glen Canyon Design Center
    Lunatic Fringe Electronics

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Don Y@3:633/10 to All on Sunday, May 31, 2026 10:41:27
    On 5/31/2026 7:20 AM, joegwinn@comcast.net wrote:
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of? Is there significant expansion
    (or shrinkage) during curing?

    Even dry-seeming concrete is a reasonably good electrical conductor - implements a resistor.

    I figured a conformal coating would "isolate" the devices,
    electrically -- it worked well enough for salt pray.

    But, I'm not sure how well that would address leads
    and the lime content.

    Or, how warm things would get during curing (as that would
    affect the coating, too).

    Hard to get firm numbers on that (*internal* temperatures):

    "When curing, concrete can reach some impressive temperatures, thanks
    to the exothermic reaction during hydration. That?s right?concrete?s
    getting ts sweat on, potentially hitting anywhere from 70øF to over
    150øF, depending on the mix and environmental conditions."

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Jeff Liebermann@3:633/10 to All on Sunday, May 31, 2026 10:59:11
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of? Is there significant expansion
    (or shrinkage) during curing?

    Concrete shrinks during curing. You can buy thermally stable concrete (hydraulic cement) which is fairly stable. There are many factors
    that affect the amount of expansion or shrinkage. This might help: <https://www.terrayamaken.com/en/understanding-plastic-shrinkage-cracking-in-concrete/>

    Other things to worry about:
    - Air bubbles from outgassing. That's why vibrators are used in
    concrete foundation construction.
    - Shrinkage during curing which will cause cracks.
    - High water content (about 50% water) in concrete will corrode
    components.
    - High water content (about 50% water) can expand and crack concrete
    when frozen. The water can also turn to vapor when heated above 100C
    causing spalling.
    - Chlorine (salt water) contamination will corrode copper.
    - Lack of adhesion to components will produce a cavity for water to
    collect.

    Instead of reinventing the wheel, perhaps you should consider using
    epoxy, urethane or silicone potting compounds. <https://en.wikipedia.org/wiki/Potting_(electronics)>


    --
    Jeff Liebermann jeffl@cruzio.com
    PO Box 272 http://www.LearnByDestroying.com
    Ben Lomond CA 95005-0272 AE6KS 831-336-2558


    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Don Y@3:633/10 to All on Sunday, May 31, 2026 11:49:35
    On 5/31/2026 10:59 AM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of? Is there significant expansion
    (or shrinkage) during curing?

    Concrete shrinks during curing. You can buy thermally stable concrete (hydraulic cement) which is fairly stable. There are many factors
    that affect the amount of expansion or shrinkage. This might help: <https://www.terrayamaken.com/en/understanding-plastic-shrinkage-cracking-in-concrete/>

    I only care to the extent that shrinkage alters the mechanical
    characteristics of the "potted" devices. I don't imagine their
    presence will materially affect the behavior of the encapsulant,
    itself.

    Other things to worry about:
    - Air bubbles from outgassing. That's why vibrators are used in
    concrete foundation construction.
    - Shrinkage during curing which will cause cracks.
    - High water content (about 50% water) in concrete will corrode
    components.
    - High water content (about 50% water) can expand and crack concrete
    when frozen. The water can also turn to vapor when heated above 100C
    causing spalling.
    - Chlorine (salt water) contamination will corrode copper.
    - Lack of adhesion to components will produce a cavity for water to
    collect.

    Conformal coating should maintain a barrier between the components
    and the encapsulant.

    I imagine the mortar/cement/concrete will be installed with all
    of the above in mind. I can't protect against folks who don't
    know how to handle the material. I just want to drop something
    in while they are "doing their thing".

    If the material isn't suited to the environment in which it is
    deployed, then that's not my problem, either.

    Instead of reinventing the wheel, perhaps you should consider using
    epoxy, urethane or silicone potting compounds. <https://en.wikipedia.org/wiki/Potting_(electronics)>

    Adds a step:
    - pot in epoxy
    - and THEN place potted item in mortar/cement/concrete
    And, makes the potted device arguably larger (than just
    a conformal coat would).

    I'm trying to see if that first step can be eliminated
    and that second issue avoided.

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From John R Walliker@3:633/10 to All on Sunday, May 31, 2026 21:54:05
    On 31/05/2026 19:49, Don Y wrote:
    On 5/31/2026 10:59 AM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of?ÿ Is there significant expansion
    (or shrinkage) during curing?

    Concrete shrinks during curing.ÿ You can buy thermally stable concrete
    (hydraulic cement) which is fairly stable.ÿ There are many factors
    that affect the amount of expansion or shrinkage.ÿ This might help:
    <https://www.terrayamaken.com/en/understanding-plastic-shrinkage-
    cracking-in-concrete/>

    I only care to the extent that shrinkage alters the mechanical characteristics of the "potted" devices.ÿ I don't imagine their
    presence will materially affect the behavior of the encapsulant,
    itself.

    Other things to worry about:
    - Air bubbles from outgassing.ÿ That's why vibrators are used in
    concrete foundation construction.
    - Shrinkage during curing which will cause cracks.
    - High water content (about 50% water) in concrete will corrode
    components.
    - High water content (about 50% water) can expand and crack concrete
    when frozen.ÿ The water can also turn to vapor when heated above 100C
    causing spalling.
    - Chlorine (salt water) contamination will corrode copper.
    - Lack of adhesion to components will produce a cavity for water to
    collect.

    Conformal coating should maintain a barrier between the components
    and the encapsulant.

    I imagine the mortar/cement/concrete will be installed with all
    of the above in mind.ÿ I can't protect against folks who don't
    know how to handle the material.ÿ I just want to drop something
    in while they are "doing their thing".

    If the material isn't suited to the environment in which it is
    deployed, then that's not my problem, either.

    Instead of reinventing the wheel, perhaps you should consider using
    epoxy, urethane or silicone potting compounds.
    <https://en.wikipedia.org/wiki/Potting_(electronics)>

    Adds a step:
    - pot in epoxy
    - and THEN place potted item in mortar/cement/concrete
    And, makes the potted device arguably larger (than just
    a conformal coat would).

    I'm trying to see if that first step can be eliminated
    and that second issue avoided.


    Don't expose electronic components to cement or concrete.
    It is almost certain to cause problems. I think that
    encapsulating your circuit in silicone rubber will protect
    in two ways.
    1) Its flexibility will reduce the mechanical stress on the
    components.
    2) It will isolate them from ionic contaminants which would
    otherwise either cause electrical leakage paths or cause
    corrosion - or both.
    What it will not do is prevent water from getting to your circuit.
    So long as the circuit is VERY clean before encapsulation
    this is not a problem.
    All polymers are permeable to water vapour. However, if the
    encapsulated surface is very clean this will not condense
    to liquid water and there will not be any problem.
    If, on the other hand, there is a little salt on the
    surface of the encapsulated component, perhaps from a
    fingerprint, a tiny blister of salty water will form.
    Osmosis will then drive water vapour through the polymer
    in the direction of that salty blister which will then get
    bigger. You will end up with a component surrounded with
    slightly salty water which will not be a good environment
    for your circuit.
    The bottom line is: Make your circuit very clean. Washing
    with recirculated deionised water for many hours will do this.
    Encapsulate with silicone rubber. If you use the type that
    evolves acetic acid, allow plenty of time for this to diffuse
    out before doing anything else.
    If you want to see references to the original research on this
    which related to medical implants I can dig them out...
    John



    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From joegwinn@3:633/10 to All on Sunday, May 31, 2026 17:20:36
    On Sun, 31 May 2026 11:49:35 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 5/31/2026 10:59 AM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of? Is there significant expansion
    (or shrinkage) during curing?

    Concrete shrinks during curing. You can buy thermally stable concrete
    (hydraulic cement) which is fairly stable. There are many factors
    that affect the amount of expansion or shrinkage. This might help:
    <https://www.terrayamaken.com/en/understanding-plastic-shrinkage-cracking-in-concrete/>

    I only care to the extent that shrinkage alters the mechanical >characteristics of the "potted" devices. I don't imagine their
    presence will materially affect the behavior of the encapsulant,
    itself.

    Other things to worry about:
    - Air bubbles from outgassing. That's why vibrators are used in
    concrete foundation construction.
    - Shrinkage during curing which will cause cracks.
    - High water content (about 50% water) in concrete will corrode
    components.
    - High water content (about 50% water) can expand and crack concrete
    when frozen. The water can also turn to vapor when heated above 100C
    causing spalling.
    - Chlorine (salt water) contamination will corrode copper.
    - Lack of adhesion to components will produce a cavity for water to
    collect.

    Conformal coating should maintain a barrier between the components
    and the encapsulant.

    I imagine the mortar/cement/concrete will be installed with all
    of the above in mind. I can't protect against folks who don't
    know how to handle the material. I just want to drop something
    in while they are "doing their thing".

    If the material isn't suited to the environment in which it is
    deployed, then that's not my problem, either.

    Yes it is. If the drop-in item is potted with a rigid material, and
    then embedded in a rigid cement, the stresses and strains in the
    cement will crack the item.

    If the item must be drop-in, its "conformal" coat must be thick and
    softish, and is most easily molded or cast in a thin shell. As
    mentioned later [1], Polyurethane potting is likely to be suitable.

    It would also be useful to include a thermocouple or thermistor in the
    item, so the actual temperature can be measured versus guessed.


    Adds a step:
    - pot in epoxy
    - and THEN place potted item in mortar/cement/concrete
    And, makes the potted device arguably larger (than just
    a conformal coat would).

    I'm trying to see if that first step can be eliminated
    and that second issue avoided.

    Not clear. How big are these concrete things? If they are tiny, just
    make it all urethane potting.

    Joe


    [1] Instead of reinventing the wheel, perhaps you should consider using
    epoxy, urethane or silicone potting compounds.
    <https://en.wikipedia.org/wiki/Potting_(electronics)>

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Jeff Liebermann@3:633/10 to All on Sunday, May 31, 2026 14:24:32
    On Sun, 31 May 2026 11:49:35 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    Conformal coating should maintain a barrier between the components
    and the encapsulant.

    That depends on the composition and thickness of your conformal
    coating. If the coating is brittle, it might crumble or crack. If it
    flexes, it might tear. If the coating has bubbles or gaps, you might
    end up with a biological reactor.

    Full disclosure: I used to design marine radios. The art of
    protecting electronics from the environment is not simple or obvious.
    Most of the horror stories are true. I also worked as an "assistant
    embalmer" (which meant I mostly swept the floor) when I was in high
    skool. I didn't have any contact with the corpses but did get to
    watch the procedures. If you plan to bury something that is conformal
    coated in concrete, it might be wise to first consult the applicable
    state laws and regulations or at least consult a mortuary for burial
    advice.

    Hint: Make sure that whatever it is you're burying is legally dead
    before proceeding. The un-dead have been known to inconveniently rise
    to the occasion at inconvenient times.

    I imagine the mortar/cement/concrete will be installed with all
    of the above in mind. I can't protect against folks who don't
    know how to handle the material. I just want to drop something
    in while they are "doing their thing".

    I'm not sure what you're encapsulating in concrete but this might help <https://www.youtube.com/watch?v=zyFAlep9CA4> (8:47) <https://www.youtube.com/shorts/FNSfXRcOqW4>
    Be sure to bring some antiemetic (nausea prevention drug).

    If the material isn't suited to the environment in which it is
    deployed, then that's not my problem, either.

    That's called littering. I suggest you dispose of the incompatible
    material in an environmentally correct manner.

    Adds a step:
    - pot in epoxy
    - and THEN place potted item in mortar/cement/concrete
    And, makes the potted device arguably larger (than just
    a conformal coat would).

    Burial pots and jars are available. Conformal coating of the contents
    are probably billed separately:
    <https://en.wikipedia.org/wiki/Jar_burial>

    I'm trying to see if that first step can be eliminated
    and that second issue avoided.

    Conformal coating and potting can probably replaced by something more convenient. I suggest immolation, cremation or burial at sea as
    potential alternatives.


    --
    Jeff Liebermann jeffl@cruzio.com
    PO Box 272 http://www.LearnByDestroying.com
    Ben Lomond CA 95005-0272 AE6KS 831-336-2558


    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Don Y@3:633/10 to All on Sunday, May 31, 2026 15:41:35
    On 5/31/2026 1:54 PM, John R Walliker wrote:
    On 31/05/2026 19:49, Don Y wrote:
    On 5/31/2026 10:59 AM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of?ÿ Is there significant expansion
    (or shrinkage) during curing?

    Concrete shrinks during curing.ÿ You can buy thermally stable concrete
    (hydraulic cement) which is fairly stable.ÿ There are many factors
    that affect the amount of expansion or shrinkage.ÿ This might help:
    <https://www.terrayamaken.com/en/understanding-plastic-shrinkage- cracking-
    in-concrete/>

    I only care to the extent that shrinkage alters the mechanical
    characteristics of the "potted" devices.ÿ I don't imagine their
    presence will materially affect the behavior of the encapsulant,
    itself.

    Other things to worry about:
    - Air bubbles from outgassing.ÿ That's why vibrators are used in
    concrete foundation construction.
    - Shrinkage during curing which will cause cracks.
    - High water content (about 50% water) in concrete will corrode
    components.
    - High water content (about 50% water) can expand and crack concrete
    when frozen.ÿ The water can also turn to vapor when heated above 100C
    causing spalling.
    - Chlorine (salt water) contamination will corrode copper.
    - Lack of adhesion to components will produce a cavity for water to
    collect.

    Conformal coating should maintain a barrier between the components
    and the encapsulant.

    I imagine the mortar/cement/concrete will be installed with all
    of the above in mind.ÿ I can't protect against folks who don't
    know how to handle the material.ÿ I just want to drop something
    in while they are "doing their thing".

    If the material isn't suited to the environment in which it is
    deployed, then that's not my problem, either.

    Instead of reinventing the wheel, perhaps you should consider using
    epoxy, urethane or silicone potting compounds.
    <https://en.wikipedia.org/wiki/Potting_(electronics)>

    Adds a step:
    - pot in epoxy
    - and THEN place potted item in mortar/cement/concrete
    And, makes the potted device arguably larger (than just
    a conformal coat would).

    I'm trying to see if that first step can be eliminated
    and that second issue avoided.

    Don't expose electronic components to cement or concrete.

    I imagine a conformal coating to act as an environmental
    and electrical barrier between the device and its encapsulant.
    When I was doing marine navigation kit, we coated everything
    (regardless of how deeply placed in its enclosure it might be)
    and never had problems with salt spray, fish guts, etc.
    interfering with the operation of the devices.

    [*Repair*, OTOH, was a chore as getting the coating OFF
    was no easy task]

    It is almost certain to cause problems.ÿ I think that
    encapsulating your circuit in silicone rubber will protect
    in two ways.
    1) Its flexibility will reduce the mechanical stress on the
    components.
    2)ÿ It will isolate them from ionic contaminants which would
    otherwise either cause electrical leakage paths or cause
    corrosion - or both.

    How would this be better/worse than a regular conformal coating?
    The durometer of the coating -- and its thickness -- would
    give a certain (predicatable) amount of protection to mechanical
    stress around the device. There are always limits to what
    a given approach can tolerate (I doubt anything embedded in the
    walls of the World Trade Center would have survived THAT sort
    of stress)

    What it will not do is prevent water from getting to your circuit.
    So long as the circuit is VERY clean before encapsulation
    this is not a problem.
    All polymers are permeable to water vapour.ÿ However, if the
    encapsulated surface is very clean this will not condense
    to liquid water and there will not be any problem.
    If, on the other hand, there is a little salt on the
    surface of the encapsulated component, perhaps from a
    fingerprint, a tiny blister of salty water will form.
    Osmosis will then drive water vapour through the polymer
    in the direction of that salty blister which will then get
    bigger.ÿ You will end up with a component surrounded with
    slightly salty water which will not be a good environment
    for your circuit.
    The bottom line is:ÿ Make your circuit very clean.ÿ Washing
    with recirculated deionised water for many hours will do this.
    Encapsulate with silicone rubber.ÿ If you use the type that
    evolves acetic acid, allow plenty of time for this to diffuse
    out before doing anything else.

    So, how did the conformal coatings we put on the radios,
    autopilots, plotters, etc. manage to survive in direct
    salt spray (e.g., the internal electronics in the plotter
    were "vented" by nature of the fact that the plotting mechanism
    required long openings to travel across the plotting surface)?

    I worked on a device used to assay blood samples that had
    exposed circuit components that could be tainted with
    blood, reagents, etc. -- protected with a similar conformal
    coating.

    [Granted, a lab technician would probably be more conscientious than
    a fisherman at maintaining his kit -- and, doing so in a more
    hospitable environment where the kit is accessible without having
    to remove covers while at sea]

    If you want to see references to the original research on this
    which related to medical implants I can dig them out...

    Why "concrete and medical" implants? What were you trying to
    embed -- and, in what?

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Don Y@3:633/10 to All on Sunday, May 31, 2026 16:26:57
    On 5/31/2026 2:20 PM, joegwinn@comcast.net wrote:
    On Sun, 31 May 2026 11:49:35 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 5/31/2026 10:59 AM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of? Is there significant expansion
    (or shrinkage) during curing?

    Concrete shrinks during curing. You can buy thermally stable concrete
    (hydraulic cement) which is fairly stable. There are many factors
    that affect the amount of expansion or shrinkage. This might help:
    <https://www.terrayamaken.com/en/understanding-plastic-shrinkage-cracking-in-concrete/>

    I only care to the extent that shrinkage alters the mechanical
    characteristics of the "potted" devices. I don't imagine their
    presence will materially affect the behavior of the encapsulant,
    itself.

    Other things to worry about:
    - Air bubbles from outgassing. That's why vibrators are used in
    concrete foundation construction.
    - Shrinkage during curing which will cause cracks.
    - High water content (about 50% water) in concrete will corrode
    components.
    - High water content (about 50% water) can expand and crack concrete
    when frozen. The water can also turn to vapor when heated above 100C
    causing spalling.
    - Chlorine (salt water) contamination will corrode copper.
    - Lack of adhesion to components will produce a cavity for water to
    collect.

    Conformal coating should maintain a barrier between the components
    and the encapsulant.

    I imagine the mortar/cement/concrete will be installed with all
    of the above in mind. I can't protect against folks who don't
    know how to handle the material. I just want to drop something
    in while they are "doing their thing".

    If the material isn't suited to the environment in which it is
    deployed, then that's not my problem, either.

    Yes it is. If the drop-in item is potted with a rigid material, and
    then embedded in a rigid cement, the stresses and strains in the
    cement will crack the item.

    That depends on WHAT it is embedded in, right? And, what THAT is
    *reasonably* expected to experience.

    Should I ensure that it could survive being embedded in the
    concrete launch pad under an exploding "starship"?

    If I embed it in a decorative fountain cast from concrete,
    should it survive someone taking a jack-hammer to said fountain?

    I.e., in the former case, one would anticipate that it is possible
    (even if not "highly likely") that an explosion could occur in
    the environment and some assessment of the cost of losing that
    bit of kit weighed into the cost of embedding it.

    In the latter case, one would anticipate that the most likely
    stresses encountered would be if the fountain (was) toppled
    (through mechanical intervention or high winds, etc.)

    If the item must be drop-in, its "conformal" coat must be thick and
    softish, and is most easily molded or cast in a thin shell. As
    mentioned later [1], Polyurethane potting is likely to be suitable.

    It only has to be soft enough to absorb *enough* of the flex that
    might exist over the dimensions of the embedded object, beyond what
    the embedded object can tolerate on its own.

    It would also be useful to include a thermocouple or thermistor in the
    item, so the actual temperature can be measured versus guessed.

    You only need that when the device is potted. If the temperature
    gets too high, what recourse do you have -- the device is already
    *embedded*!

    Measuring (without necessitating the presence of the embedded
    device) is necessary just to ensure the chosen process (for
    the particular application) won't subject the embedded device
    to extremes that could damage/destroy it as that would, presumably,
    necessitate discarding the embedding structure (considerably more
    costly -- labor -- than a device)

    Adds a step:
    - pot in epoxy
    - and THEN place potted item in mortar/cement/concrete
    And, makes the potted device arguably larger (than just
    a conformal coat would).

    I'm trying to see if that first step can be eliminated
    and that second issue avoided.

    Not clear. How big are these concrete things? If they are tiny, just
    make it all urethane potting.

    I want a technology that will let me make the "pottable devices"
    as small as possible. E.g., if I want to slip one into a mortar
    line between bricks/blocks, I don't want to impact the process
    that is normally used to lay brick/block.

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Don Y@3:633/10 to All on Sunday, May 31, 2026 16:31:24
    On 5/31/2026 2:24 PM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 11:49:35 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    Conformal coating should maintain a barrier between the components
    and the encapsulant.

    That depends on the composition and thickness of your conformal
    coating. If the coating is brittle, it might crumble or crack. If it flexes, it might tear. If the coating has bubbles or gaps, you might
    end up with a biological reactor.

    Full disclosure: I used to design marine radios. The art of
    protecting electronics from the environment is not simple or obvious.

    Yes, I designed LORAN receivers, plotters and autopilots. I am
    well aware of what salt spray can do to kit -- in very short order.

    [If you've ever seen wrought iron railings on houses/structures
    "near the beach", this is very dramatic!]

    Most of the horror stories are true. I also worked as an "assistant embalmer" (which meant I mostly swept the floor) when I was in high
    skool. I didn't have any contact with the corpses but did get to
    watch the procedures. If you plan to bury something that is conformal
    coated in concrete, it might be wise to first consult the applicable
    state laws and regulations or at least consult a mortuary for burial
    advice.

    My B-in-L was an embalmer. Kinda creepy but someone has to do it.

    Hint: Make sure that whatever it is you're burying is legally dead
    before proceeding. The un-dead have been known to inconveniently rise
    to the occasion at inconvenient times.

    If the material isn't suited to the environment in which it is
    deployed, then that's not my problem, either.

    That's called littering. I suggest you dispose of the incompatible
    material in an environmentally correct manner.

    If the device is embedded in another device and the other device fails,
    then it's not "litter" but "debris".


    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Jeff Liebermann@3:633/10 to All on Sunday, May 31, 2026 19:11:08
    On Sun, 31 May 2026 16:31:24 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 5/31/2026 2:24 PM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 11:49:35 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    Conformal coating should maintain a barrier between the components
    and the encapsulant.

    That depends on the composition and thickness of your conformal
    coating. If the coating is brittle, it might crumble or crack. If it
    flexes, it might tear. If the coating has bubbles or gaps, you might
    end up with a biological reactor.

    Full disclosure: I used to design marine radios. The art of
    protecting electronics from the environment is not simple or obvious.

    Yes, I designed LORAN receivers, plotters and autopilots. I am
    well aware of what salt spray can do to kit -- in very short order.

    I worked for Intech Inc, Santa Clara at SJC airport. In 9.5 years, I
    helped design a 27MHz pager (yech), AN/SRD-21 VHF homer, AN/SRD-22 VHF
    Doppler DF, VHF "sign post" vehicle locator, various 1.6 to 30MHz SSB transceivers, various HF power amps, some minor test equipment, some
    UHF SCADA transceivers for SoCal Edison, and probably some other stuff
    that I can't excavate from my failing memory. (Note that I did not
    design the entire transceiver). For the military direction finders,
    passing the MIL-STD-810 salt fog test was difficult. <https://keystonecompliance.com/mil-std-810/salt-fog/>

    Much later, I somehow ended up doing damage control on various
    consumer electronics designs. There were some devices environmental
    problems. Typically, the culprit was a high impedance design, where a
    small amount of water would literally short PCB traces or components. Sometimes, the high impedances were necessary, but recalculating the
    components to lower impedances usually solved the problems. The lower impedance also helped the device survive in a high humidity and/or
    moisture condensing environment.

    [If you've ever seen wrought iron railings on houses/structures
    "near the beach", this is very dramatic!]

    At various times, I've resided in the "fog belt" near the ocean. I
    don't recall seeing any wrought iron hand railing. As I vaguely
    recall, the hand rails were redwood with layers of sealer, stain or
    paint.

    Most of the horror stories are true. I also worked as an "assistant
    embalmer" (which meant I mostly swept the floor) when I was in high
    skool. I didn't have any contact with the corpses but did get to
    watch the procedures. If you plan to bury something that is conformal
    coated in concrete, it might be wise to first consult the applicable
    state laws and regulations or at least consult a mortuary for burial
    advice.

    My B-in-L was an embalmer. Kinda creepy but someone has to do it.

    As long as he doesn't try to raise the dead, he'll be ok. I found the relatives of the deceased to be far more creepy than the staff. The
    TV show "The Addams Family" was probably their template.

    Hint: Make sure that whatever it is you're burying is legally dead
    before proceeding. The un-dead have been known to inconveniently rise
    to the occasion at inconvenient times.

    If the material isn't suited to the environment in which it is
    deployed, then that's not my problem, either.

    That's called littering. I suggest you dispose of the incompatible
    material in an environmentally correct manner.

    If the device is embedded in another device and the other device fails,
    then it's not "litter" but "debris".

    When viewed from a distance, there is little difference between litter
    and debris.



    --
    Jeff Liebermann jeffl@cruzio.com
    PO Box 272 http://www.LearnByDestroying.com
    Ben Lomond CA 95005-0272 AE6KS 831-336-2558


    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Don Y@3:633/10 to All on Sunday, May 31, 2026 19:56:00
    On 5/31/2026 7:11 PM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 16:31:24 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 5/31/2026 2:24 PM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 11:49:35 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    Conformal coating should maintain a barrier between the components
    and the encapsulant.

    That depends on the composition and thickness of your conformal
    coating. If the coating is brittle, it might crumble or crack. If it
    flexes, it might tear. If the coating has bubbles or gaps, you might
    end up with a biological reactor.

    Full disclosure: I used to design marine radios. The art of
    protecting electronics from the environment is not simple or obvious.

    Yes, I designed LORAN receivers, plotters and autopilots. I am
    well aware of what salt spray can do to kit -- in very short order.

    I worked for Intech Inc, Santa Clara at SJC airport. In 9.5 years, I
    helped design a 27MHz pager (yech), AN/SRD-21 VHF homer, AN/SRD-22 VHF Doppler DF, VHF "sign post" vehicle locator, various 1.6 to 30MHz SSB transceivers, various HF power amps, some minor test equipment, some
    UHF SCADA transceivers for SoCal Edison, and probably some other stuff
    that I can't excavate from my failing memory. (Note that I did not
    design the entire transceiver). For the military direction finders,
    passing the MIL-STD-810 salt fog test was difficult. <https://keystonecompliance.com/mil-std-810/salt-fog/>

    Working and living minutes from the ocean (atlantic), we could
    usually find someone willing to take us out to "field test"
    our kit -- usually small (35 ft) "working boats", no enclosed
    bridge, etc.

    And, we had our own shake-n-bake facilities in the shop. So,
    before we *got* to sea trials, we were reasonably sure we had
    a viable product. Whether it was a radar, loran/omega receiver,
    position plotter, autopilot, etc.

    I've not encountered any other shop with the range of technologies
    that were available, there. (metal shop, paint shop, wave, microwave
    testing chamber, etc.)

    Much later, I somehow ended up doing damage control on various
    consumer electronics designs. There were some devices environmental problems. Typically, the culprit was a high impedance design, where a
    small amount of water would literally short PCB traces or components. Sometimes, the high impedances were necessary, but recalculating the components to lower impedances usually solved the problems. The lower impedance also helped the device survive in a high humidity and/or
    moisture condensing environment.

    The plotters were the most vulnerable devices as they had mechanisms
    that couldn't be enclosed/protected from the saltspray. And, the
    skippers would usually dick with them while at sea instead of letting
    them just "do their thing".

    Early on, we discovered they were frequently opening the protective
    cover in order to mark the chart to indicate where they'd dropped
    a lobster pot or found a school of fish. This prompted a last
    minute hack to allow them to "press a button" to have the plotter
    draw an 'X' in the hope that they would leave things covered.

    This, of course, was a win for the crew as they could extend the
    pushbutton control (like the handheld "devices" used on quiz shows)
    so they could stay aft and keep working instead of having to run
    up to the plotter to manually make those marks.

    [Of course, nowadays, you'd want to also *annotate* them -- and,
    get rid of the paper and X/Y mechanism in favor of glass]

    [If you've ever seen wrought iron railings on houses/structures
    "near the beach", this is very dramatic!]

    At various times, I've resided in the "fog belt" near the ocean. I
    don't recall seeing any wrought iron hand railing. As I vaguely
    recall, the hand rails were redwood with layers of sealer, stain or
    paint.

    We used to vacation in florida, a few blocks from the sea, each year.
    I distinctly recall seeing wrought iron railings (to keep folks
    from falling off their porches, etc.) that were *etched* from the
    salty air. "Gee, out wrought iron railings at home don't look like that!"

    Most of the horror stories are true. I also worked as an "assistant
    embalmer" (which meant I mostly swept the floor) when I was in high
    skool. I didn't have any contact with the corpses but did get to
    watch the procedures. If you plan to bury something that is conformal
    coated in concrete, it might be wise to first consult the applicable
    state laws and regulations or at least consult a mortuary for burial
    advice.

    My B-in-L was an embalmer. Kinda creepy but someone has to do it.

    As long as he doesn't try to raise the dead, he'll be ok. I found the relatives of the deceased to be far more creepy than the staff. The
    TV show "The Addams Family" was probably their template.

    He seemed to think nothing of it. He would often disappear for a few
    hours to "plug some guy". I didn't want to know any of the details...

    Hint: Make sure that whatever it is you're burying is legally dead
    before proceeding. The un-dead have been known to inconveniently rise
    to the occasion at inconvenient times.

    If the material isn't suited to the environment in which it is
    deployed, then that's not my problem, either.

    That's called littering. I suggest you dispose of the incompatible
    material in an environmentally correct manner.

    If the device is embedded in another device and the other device fails,
    then it's not "litter" but "debris".

    When viewed from a distance, there is little difference between litter
    and debris.

    Litter is intentional. Debris is usually the result of an accident.

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Carlos E.R.@3:633/10 to All on Monday, June 01, 2026 13:10:16
    On 2026-05-31 22:54, John R Walliker wrote:
    On 31/05/2026 19:49, Don Y wrote:
    On 5/31/2026 10:59 AM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    ...

    Don't expose electronic components to cement or concrete.
    It is almost certain to cause problems.ÿ I think that
    encapsulating your circuit in silicone rubber will protect
    in two ways.
    1) Its flexibility will reduce the mechanical stress on the
    components.
    2)ÿ It will isolate them from ionic contaminants which would
    otherwise either cause electrical leakage paths or cause
    corrosion - or both.
    What it will not do is prevent water from getting to your circuit.
    So long as the circuit is VERY clean before encapsulation
    this is not a problem.
    All polymers are permeable to water vapour.ÿ However, if the
    encapsulated surface is very clean this will not condense
    to liquid water and there will not be any problem.
    If, on the other hand, there is a little salt on the
    surface of the encapsulated component, perhaps from a
    fingerprint, a tiny blister of salty water will form.
    Osmosis will then drive water vapour through the polymer
    in the direction of that salty blister which will then get
    bigger.ÿ You will end up with a component surrounded with
    slightly salty water which will not be a good environment
    for your circuit.

    You have suddenly reminded me of a problem I had with a particular IR
    remote control.

    The side of the PCB that touched the rubber membrane with the buttons
    got wet after few months of usage, and the buttons would not act. I
    would disassemble the thing, wash and dry it, and close again, but
    eventually they thing got wet inside.

    I'm not sure if the liquid was slightly oily, though. Long ago.



    --
    Cheers, Carlos.
    ES??, EU??;

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Carlos E.R.@3:633/10 to All on Monday, June 01, 2026 13:22:23
    On 2026-06-01 04:56, Don Y wrote:
    On 5/31/2026 7:11 PM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 16:31:24 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:


    [If you've ever seen wrought iron railings on houses/structures
    "near the beach", this is very dramatic!]

    At various times, I've resided in the "fog belt" near the ocean.ÿ I
    don't recall seeing any wrought iron hand railing.ÿ As I vaguely
    recall, the hand rails were redwood with layers of sealer, stain or
    paint.

    We used to vacation in florida, a few blocks from the sea, each year.
    I distinctly recall seeing wrought iron railings (to keep folks
    from falling off their porches, etc.) that were *etched* from the
    salty air.ÿ "Gee, out wrought iron railings at home don't look like that!"

    My family had a house at a place in Spain called La Manga. It is a long
    strip of land between the Mediterranean and a very salty inner sea. In
    that place, aluminum corroded. Stainless steel got (big) spots. Salty
    humidity almost like living in a boat.

    --
    Cheers, Carlos.
    ES??, EU??;

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Miguel Gimenez@3:633/10 to All on Monday, June 01, 2026 13:49:39
    El 01/06/2026 a las 13:10, Carlos E.R. escribi¢:

    You have suddenly reminded me of a problem I had with a particular IR
    remote control.

    The side of the PCB that touched the rubber membrane with the buttons
    got wet after few months of usage, and the buttons would not act. I
    would disassemble the thing, wash and dry it, and close again, but eventually they thing got wet inside.

    I'm not sure if the liquid was slightly oily, though. Long ago.

    The liquid is silicone grease due to a bad curing of the silicone
    membrane, it is like the membrane is sweating. Most used keys are more
    prone to fail, as pressing the keys makes the liquid go out, similar to pressing a sponge.

    Ethanol will clean this, although it will return in a while (about three months for bad remotes, years for not-so-bad ones).

    --
    Saludos
    Miguel Gimenez


    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Carlos E.R.@3:633/10 to All on Monday, June 01, 2026 14:19:29
    On 2026-06-01 13:49, Miguel Gimenez wrote:
    El 01/06/2026 a las 13:10, Carlos E.R. escribi¢:

    You have suddenly reminded me of a problem I had with a particular IR
    remote control.

    The side of the PCB that touched the rubber membrane with the buttons
    got wet after few months of usage, and the buttons would not act. I
    would disassemble the thing, wash and dry it, and close again, but
    eventually they thing got wet inside.

    I'm not sure if the liquid was slightly oily, though. Long ago.

    The liquid is silicone grease due to a bad curing of the silicone
    membrane, it is like the membrane is sweating. Most used keys are more
    prone to fail, as pressing the keys makes the liquid go out, similar to pressing a sponge.

    Ethanol will clean this, although it will return in a while (about three months for bad remotes, years for not-so-bad ones).


    That figures.

    --
    Cheers, Carlos.
    ES??, EU??;

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From legg@3:633/10 to All on Monday, June 01, 2026 10:19:42
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of? Is there significant expansion
    (or shrinkage) during curing?

    Can't imagine why you would want to, but I'd seal the
    package in conventional, flexible materials first, to
    protect from environment and absorb stress.

    Small packages can be inserted into preformed concrete
    through drilling and filling processes.

    RL

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Don Y@3:633/10 to All on Monday, June 01, 2026 08:19:44
    On 6/1/2026 4:10 AM, Carlos E.R. wrote:
    You have suddenly reminded me of a problem I had with a particular IR remote control.

    The side of the PCB that touched the rubber membrane with the buttons got wet
    after few months of usage, and the buttons would not act. I would disassemble
    the thing, wash and dry it, and close again, but eventually they thing got wet
    inside.

    I'm not sure if the liquid was slightly oily, though. Long ago.

    I think those are likely high-impedance inputs, easily "misled".


    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Don Y@3:633/10 to All on Monday, June 01, 2026 08:25:45
    On 6/1/2026 4:22 AM, Carlos E.R. wrote:
    On 2026-06-01 04:56, Don Y wrote:
    On 5/31/2026 7:11 PM, Jeff Liebermann wrote:
    On Sun, 31 May 2026 16:31:24 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:


    [If you've ever seen wrought iron railings on houses/structures
    "near the beach", this is very dramatic!]

    At various times, I've resided in the "fog belt" near the ocean.ÿ I
    don't recall seeing any wrought iron hand railing.ÿ As I vaguely
    recall, the hand rails were redwood with layers of sealer, stain or
    paint.

    We used to vacation in florida, a few blocks from the sea, each year.
    I distinctly recall seeing wrought iron railings (to keep folks
    from falling off their porches, etc.) that were *etched* from the
    salty air.ÿ "Gee, out wrought iron railings at home don't look like that!"

    My family had a house at a place in Spain called La Manga. It is a long strip
    of land between the Mediterranean and a very salty inner sea. In that place, aluminum corroded. Stainless steel got (big) spots. Salty humidity almost like
    living in a boat.

    Yes, I had never seen metal corroded so was curious as to what was happening (we started making this annual trip when I was about 5yo). I distinctly remember the *tourquoise* (a new color for a very young child!) paint
    they had slathered on the railings in an attempt to avoid replacing them.

    [I also remember seeing sea turtles laying their eggs alongside me, on the beach! But, "the grownups" wouldn't let me pet them! :< Amusing which memories get seared into our minds...]


    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Don Y@3:633/10 to All on Monday, June 01, 2026 08:31:46
    On 6/1/2026 7:19 AM, legg wrote:
    On Sun, 31 May 2026 07:16:49 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    The presence of lime can push the pH up considerably.

    Water migration into packages during curing.

    Water wicking into packages via leads during curing.

    Increased temperature during curing.

    Anything else to be wary of? Is there significant expansion
    (or shrinkage) during curing?

    Can't imagine why you would want to, but I'd seal the
    package in conventional, flexible materials first, to
    protect from environment and absorb stress.

    I don't (yet) have specific applications but want to
    inventory the technologies that I could exploit.
    I'd hate to have to fasten an outdoor-rated Jbox
    *to* a surface just for the purpose of housing a
    tiny bit of kit! It's costly and cosmetically
    unappealing.

    Small packages can be inserted into preformed concrete
    through drilling and filling processes.

    Yes. Or, chipping away at a mortar line and
    slathering fresh mortar over the wound, afterwards.

    The issue becomes one of remembering *where* such
    devices are located (unless you mark them in some
    way that isn't similarly poor cosmetically)

    Most homes (here) are stucco. It is not uncommon for the
    "earthing conductor" to be hidden in the stucco as
    there is no real reason for it to be visible. Or,
    even accessible.

    Sadly, most homes that subscribe to "services" end up
    with cables (typ black) draped vertically down their
    faces as the cost of hiding them is considerable with
    slab-based construction (and frontier-style elevations)

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Liz Tuddenham@3:633/10 to All on Monday, June 01, 2026 20:34:01
    Don Y <blockedofcourse@foo.invalid> wrote:

    [...]
    The issue becomes one of remembering *where* such
    devices are located (unless you mark them in some
    way that isn't similarly poor cosmetically)

    Bury a magnet with them and find it with a pocket compass.

    I used that method to make a hidden boundary markerwhen I suspected an unscrupulous neighbour might move the visible marker.


    --
    ~ Liz Tuddenham ~
    (Remove the ".invalid"s and add ".co.uk" to reply)
    www.poppyrecords.co.uk

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Don Y@3:633/10 to All on Monday, June 01, 2026 13:42:19
    On 6/1/2026 12:34 PM, Liz Tuddenham wrote:
    Don Y <blockedofcourse@foo.invalid> wrote:

    The issue becomes one of remembering *where* such
    devices are located (unless you mark them in some
    way that isn't similarly poor cosmetically)

    Bury a magnet with them and find it with a pocket compass.

    That's a good idea! In general, I've just been "taking good
    measurements". But, those can get misplaced, over time...

    I used that method to make a hidden boundary markerwhen I suspected an unscrupulous neighbour might move the visible marker.

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From John R Walliker@3:633/10 to All on Tuesday, June 02, 2026 12:21:16
    On 01/06/2026 21:42, Don Y wrote:
    On 6/1/2026 12:34 PM, Liz Tuddenham wrote:
    Don Y <blockedofcourse@foo.invalid> wrote:

    The issue becomes one of remembering *where* such
    devices are located (unless you mark them in some
    way that isn't similarly poor cosmetically)

    Bury a magnet with them and find it with a pocket compass.

    That's a good idea!ÿ In general, I've just been "taking good
    measurements".ÿ But, those can get misplaced, over time...

    I used that method to make a hidden boundary markerwhen I suspected an
    unscrupulous neighbour might move the visible marker.

    Did the neighbour ever move the visible marker?


    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Liz Tuddenham@3:633/10 to All on Tuesday, June 02, 2026 15:02:35
    John R Walliker <jrwalliker@gmail.com> wrote:

    On 01/06/2026 21:42, Don Y wrote:
    On 6/1/2026 12:34 PM, Liz Tuddenham wrote:
    Don Y <blockedofcourse@foo.invalid> wrote:

    The issue becomes one of remembering *where* such
    devices are located (unless you mark them in some
    way that isn't similarly poor cosmetically)

    Bury a magnet with them and find it with a pocket compass.

    That's a good idea!ÿ In general, I've just been "taking good
    measurements".ÿ But, those can get misplaced, over time...

    I used that method to make a hidden boundary markerwhen I suspected an
    unscrupulous neighbour might move the visible marker.

    Did the neighbour ever move the visible marker?

    To my surprise he hasn't yet - but I still don't trust him.


    --
    ~ Liz Tuddenham ~
    (Remove the ".invalid"s and add ".co.uk" to reply)
    www.poppyrecords.co.uk

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)