| Topic: |
Science > Physics |
| User: |
"Steven" |
| Date: |
05 Oct 2003 07:25:34 PM |
| Object: |
strange incident |
Hi,
I will state the short version of this story. I recently purchased a piece
of plexyglass. While in my house when I wrote on the plexyglass with an
erasable marker (expo) I was surprised at how easy I was able to erase my
writing. The other day I had the piece of plexy glass and an expo marker in
my car (outside temp was about 55 degrees F) for about 45 minutes when I
went into my friends house. About 10 minutes later, after writing on the
plexyglass, I was unable to erase the writing on the plexyglass- eventually
with great effort it was finally cleared. I suspect this has to do with a
temperature change. Now my questions are as follows:
1) exactly what happened????
2) was the cause of my problem due to the marker, the plexyglass, or both?
3) can I treat the plexyglass with something that would prevent this problem
in the future?
.
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| User: "Uncle Al" |
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| Title: Re: strange incident |
05 Oct 2003 07:52:14 PM |
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Steven wrote:
Hi,
I will state the short version of this story. I recently purchased a piece
of plexyglass. While in my house when I wrote on the plexyglass with an
erasable marker (expo) I was surprised at how easy I was able to erase my
writing. The other day I had the piece of plexy glass and an expo marker in
my car (outside temp was about 55 degrees F) for about 45 minutes when I
went into my friends house. About 10 minutes later, after writing on the
plexyglass, I was unable to erase the writing on the plexyglass- eventually
with great effort it was finally cleared. I suspect this has to do with a
temperature change. Now my questions are as follows:
1) exactly what happened????
2) was the cause of my problem due to the marker, the plexyglass, or both?
3) can I treat the plexyglass with something that would prevent this problem
in the future?
The dye diffused into the plastic aided by high temp (Greenhouse
effect in the car). Try a water-based marker.
Screw the marker. Go for the gusto!
http://www.amasci.com/amateur/holo1.html
http://www.amasci.com/amateur/hand1.html
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
"Quis custodiet ipsos custodes?" The Net!
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| User: "Edward Green" |
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| Title: Re: strange incident |
06 Oct 2003 07:48:03 PM |
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Uncle Al <UncleAl0@hate.spam.net> wrote in message news:<3F80BCBE.87AE3CA1@hate.spam.net>...
Steven wrote:
Hi,
I will state the short version of this story. I recently purchased a piece
of plexyglass. While in my house when I wrote on the plexyglass with an
erasable marker (expo) I was surprised at how easy I was able to erase my
writing. The other day I had the piece of plexy glass and an expo marker in
my car (outside temp was about 55 degrees F) for about 45 minutes when I
went into my friends house. About 10 minutes later, after writing on the
plexyglass, I was unable to erase the writing on the plexyglass- eventually
with great effort it was finally cleared. I suspect this has to do with a
temperature change. Now my questions are as follows:
1) exactly what happened????
2) was the cause of my problem due to the marker, the plexyglass, or both?
3) can I treat the plexyglass with something that would prevent this problem
in the future?
The dye diffused into the plastic aided by high temp (Greenhouse
effect in the car). Try a water-based marker.
Bzzt. You fell into the reading comprehension traps in this SAT
question.
The length of time the plastic was in the car is largely irrelevent,
because he wrote on it 10 minutes later, not 45 minutes prior ...
actually, the sequence of events is unclear, but I think he wrote on
cold plastic. I say that because of the cold temperature the solvent
in the marker didn't evaporate as fast as usual, hence the pigment had
more time to percolate into the pores on the surface, where it however
could just be dislodged by vigorous mechanical application of fibers.
If it had diffused significantly into the solid, you would have to
remove material by polishing to remove the stain.
Solution: don't write on cold plastic. Slowing down one physical
process allows a second process to go further, ironically.
Screw the marker. Go for the gusto!
http://www.amasci.com/amateur/holo1.html
http://www.amasci.com/amateur/hand1.html
If it's possible to hand draw holograms on plastic, this suggests a
similar technique could produce "magic mirrors".
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| User: "Mark Fergerson" |
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| Title: Re: strange incident |
07 Oct 2003 03:41:16 PM |
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Edward Green wrote:
Uncle Al <UncleAl0@hate.spam.net> wrote in message news:<3F80BCBE.87AE3CA1@hate.spam.net>...
<snip>
http://www.amasci.com/amateur/holo1.html
http://www.amasci.com/amateur/hand1.html
If it's possible to hand draw holograms on plastic, this suggests a
similar technique could produce "magic mirrors".
As in the stuff I posted about my recent acquisition?
Turns out the little bronze darling isn't as smooth as I
thought; observing glancing reflection of a venetian blind
shows the "magic" image exists as shallow grooves in the
metal. No holography involved.
OTOH you may be right. Suggest it to Bill; he may take
the time to give it a shot..
Mark L. Fergerson
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