Which glue, available at any hardware store, for the screen

[arlen holder]

The glass-plastic-sandwich screen cracked on one mobile phone so I removed
my screen and put it on the other mobile phone (we both have the same LG
Stylo 3 plus).

It keeps falling off as the original sticky glue on the top and bottom
edges doesn't have enough remaining.

I do _not_ want to cover the original glass in liquid uv-cured glue, which
is what is likely the best from a refractive-index standpoint.

I just want temporary stick glue like that which came with the original
glass/plastic sandwich glass.

I went to both Home Depot & Lowes, neither of whom had anything that they
thought would work to solve the problem. I even tried Fixodent, which
worked perfectly but only for a few days.

What temporary sticky glue would you suggest that I can get at a local
hardware store like Ace, Home Depot, Hardware Freight, etc.?

 

[John-Del]

On Saturday, February 2, 2019 at 3:15:04 PM UTC-5, arlen holder wrote:

The glass-plastic-sandwich screen cracked on one mobile phone so I removed
my screen and put it on the other mobile phone (we both have the same LG
Stylo 3 plus).

It keeps falling off as the original sticky glue on the top and bottom
edges doesn't have enough remaining.

I do _not_ want to cover the original glass in liquid uv-cured glue, which
is what is likely the best from a refractive-index standpoint.

I just want temporary stick glue like that which came with the original
glass/plastic sandwich glass.

I went to both Home Depot & Lowes, neither of whom had anything that they
thought would work to solve the problem. I even tried Fixodent, which
worked perfectly but only for a few days.

What temporary sticky glue would you suggest that I can get at a local
hardware store like Ace, Home Depot, Hardware Freight, etc.?

That adhesive was likely developed just for that purpose. If you must know, Contact 3M. There's no company IMO that knows more about adhesives than them.

Other than that, why not just buy a new protective screen? They're like 3 bucks shipped and come with the adhesive already applied.

 

[Fox's Mercantile]

On 2/2/19 2:49 PM, John-Del wrote:

Other than that, why not just buy a new protective screen?
They're like 3 bucks shipped and come with the adhesive
already applied.

Because sci.electronics.repair is all about doing it the hard way.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

 

[Jeff Liebermann]

On Sat, 2 Feb 2019 20:15:01 -0000 (UTC), arlen holder
<arlen@arlen.com> wrote:

The glass-plastic-sandwich screen cracked on one mobile phone so I removed
my screen and put it on the other mobile phone (we both have the same LG
Stylo 3 plus).

Try the process used to seal cracks in automotive windshields:
<https://www.google.com/search?q=automotive+windshield+crack+repair>
I have no clue which product is best:
<https://www.youtube.com/watch?v=Bf5sY6FxPHc>
<https://www.youtube.com/watch?v=CM3hSYbD0-Y>
<https://www.youtube.com/watch?v=m2ZwXzZ4ZDs>
etc...



--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Jeff Liebermann]

On Sat, 2 Feb 2019 16:28:56 -0600, Fox's Mercantile <jdangus@att.net>
wrote:

On 2/2/19 2:49 PM, John-Del wrote:
Other than that, why not just buy a new protective screen?
They're like 3 bucks shipped and come with the adhesive
already applied.

Because sci.electronics.repair is all about doing it the hard way.

Welcome to the sci.electronics.repair.philosophy newsgroup.

If it were easy, it would not be fun or interesting. It would also
not require a newsgroup full of "experts" to explain how things should
be done. Sometimes, the hard way is the best way while the easy way
is an invitation to future problems.

Also, there is no single right answer for fixing anything. There are
always two or more ways to do anything. All a right, although some
are more right than others.

<http://www.learnbydestroying.com/jeffl/pics/repair/slides/Iphone4-cracked-screen-01.html>


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[arlen holder]

On Sat, 02 Feb 2019 17:58:30 -0800, Jeff Liebermann wrote:

If it were easy, it would not be fun or interesting. It would also
not require a newsgroup full of "experts" to explain how things should
be done.

Hi Jeff,

As you ascertain, the point of the question is to _learn_ about the type of
glue that has the following qualities - which can be used elsewhere in
sceitneific repair...

1. It's 'temporary' (but firm enough to stay in place);
2. It's 'sticky' (more than the Fixodent was, but far less than epoxy is);
3. It's 'viscous' (it can't _flow_ because it will cover 4 small top ports)
4. And, it adheres to glass.

Hence, for example, all _permanent_ solutions (e.g., cyanoacrylate) fail.
The Fixodent failed only because it wasn't rigid enough (i.e., not sticky).

Note this glue does _not_ need to have anywhere near the refractive index
of glass because the LG Stylo 3 Plus has a black 1.2 centimeter frame on
both top and bottom.

That means there's plenty of room for a "viscous" sticky temporary glue.
The only question,. from a chemistry standpoint, is which glue is that?

NOTE: I saw your other post, where I haven't delved into examining the
links yet, where again, matching the refractive index of glass isn't the
issue here as it might be with most screen reflector glues.

 

[arlen holder]

On Sat, 2 Feb 2019 12:49:23 -0800 (PST), John-Del wrote:

Other than that, why not just buy a new protective screen?
They're like 3 bucks shipped and come with the adhesive already applied.

Learning about the type of glue is what this question is mostly about;
although the final repair is a secondary goal (as is the ability to repair
in the future, using the knowledge learned about the type of glue).

Given that...

There are two issues here, each of which is completely different:
1. This question is about where to obtain a specific type of "glue"
2. You seem to have fantastic sources that I am not privy to (yet).

To clarify those two completely disjoint observations...
1. Why even have a "repair" group, if all you do is "replace"?
2. You must have far better sources than Amazon given the price you quoted.

For the types of glue, I'll defer a response until I can go through Jeff's
purposefully helpful response in detail (with respect to chemistry).

The _best_ I can find on Amazon, sorted by lowest price, is:
<https://www.amazon.com/s/ref=sr_st_price-asc-rank?keywords=protective+screen+lg+stylo+3+plus&sort=price-asc-rank>

The cheapest, is more than twice what you quoted, although I'm sure, in
bulk, we can find cheaper (but I only need one, or maybe two, for now).

I simply ask where & how you found the protectors for 3 bucks shipped?

 

[Martin Gregorie]

On Sun, 03 Feb 2019 14:52:11 +0000, arlen holder wrote:

1. It's 'temporary' (but firm enough to stay in place);
2. It's 'sticky' (more than the Fixodent was, but far less than epoxy
is); 3. It's 'viscous' (it can't _flow_ because it will cover 4 small
top ports)
4. And, it adheres to glass.

Hence, for example, all _permanent_ solutions (e.g., cyanoacrylate)
fail. The Fixodent failed only because it wasn't rigid enough (i.e., not
sticky).

Note this glue does _not_ need to have anywhere near the refractive
index of glass because the LG Stylo 3 Plus has a black 1.2 centimeter
frame on both top and bottom.

That means there's plenty of room for a "viscous" sticky temporary glue.
The only question,. from a chemistry standpoint, is which glue is that?

You have a 12 mm wide area to adhere the spread sticky stuff on, so have
you tried using double-sided sticky tape?

I'm suggesting the thin, transparent types that look like sellotape, not
the thicker foam tapes. These tapes come in 6mm and 12mm widths and can
be peeled off, though with some difficulty if you use the stronger
bonding types.

FWIW I use the latter to attach Mylar seals over the aileron gaps on
gliders. One strip of 15mm wide tape on the wing in front of the hinge
will keep the Mylar firmly attached for several years if its rolled down
well and its leading edge has a strip of gap tape over it to keep dust
and moisture from penetrating under the mylar, yet isn't too difficult to
get off and replace when it starts to loose its grip.


--
Martin | martin at
Gregorie | gregorie dot org

 

[Bennett Price]

On 2/2/2019 5:50 PM, Jeff Liebermann wrote:

On Sat, 2 Feb 2019 20:15:01 -0000 (UTC), arlen holder
arlen@arlen.com> wrote:

The glass-plastic-sandwich screen cracked on one mobile phone so I removed
my screen and put it on the other mobile phone (we both have the same LG
Stylo 3 plus).

Try the process used to seal cracks in automotive windshields:
https://www.google.com/search?q=automotive+windshield+crack+repair
I have no clue which product is best:
https://www.youtube.com/watch?v=Bf5sY6FxPHc
https://www.youtube.com/watch?v=CM3hSYbD0-Y
https://www.youtube.com/watch?v=m2ZwXzZ4ZDs
etc...

The This-to-That website might be of help:
https://www.thistothat.com/cgi-bin/glue.cgi?lang=en&this=Glass&that=Glass

 

[arlen holder]

On Sun, 3 Feb 2019 15:35:09 +0000 (UTC), Martin Gregorie wrote:

You have a 12 mm wide area to adhere the spread sticky stuff on, so have
you tried using double-sided sticky tape?

Hi Martin,

You are correct that there is _plenty_ of room at the top and bottom.
Also, the tape can be opaque for all we care on those two ends.

The main problem is that the glass has to be held so tightly that _just_
being stuck at the top and bottom 1.2 centimeters holds the rest of the
glass plate to the clear area of the phone glass screen (which is 12-1/2
centimeters long & 7.2 centimeters wide).

The original sticky glue (surprisingly) held the _entire_ plate to the
surface of the glass even though the glue was _only_ at the top and bottom.

To first answer your question - I have not yet tried sticky tape.

I have _not_ tried stick-sided tape, for the following 3 reasons:
o I don't have any super thin stuff (I have the thick spongy white
wall-mount 3M stuff only)
o I don't know if we can buy it in super duper thin strips (maybe)
o But even then, the _top_ 1.2 centimeters has "holes" in the middle.

The holes aren't that big of a deal (tape can be sliced easily).
It's the "thin" tape that we'd have to see if it exists.

Does it?
Let me search...

Hey.... guess what!
o *"Super thin" double-sided sticky tape does exist!*
<https://www.alibaba.com/showroom/super-thin-double-sided-adhesive-tape.html>

Now to find it in the box stores...

I'm suggesting the thin, transparent types that look like sellotape, not
the thicker foam tapes. These tapes come in 6mm and 12mm widths and can
be peeled off, though with some difficulty if you use the stronger
bonding types.

Thanks for that idea, as I didn't know that "super thin" stuff existed.

It's just not easy to find by normal searches, where, for example,
Amazon can find it but not under "thin", but under "super" or "ultra"
(mostly having to do with "strength").
o <https://www.amazon.com/Ultra-Thin-Permanent-Double-Sided-Photography-Scrapbooking/dp/B01NBJVU04/>

As an example, a search for "ultra thin double sided tape" gets
almost exclusively hits that are NOT ultra thin double sided tape!

FWIW I use the latter to attach Mylar seals over the aileron gaps on
gliders. One strip of 15mm wide tape on the wing in front of the hinge
will keep the Mylar firmly attached for several years if its rolled down
well and its leading edge has a strip of gap tape over it to keep dust
and moisture from penetrating under the mylar, yet isn't too difficult to
get off and replace when it starts to loose its grip.

I _like_ the idea of the "ultra-thin double-sided" tape, which, I admit,
until you mentioned it, and until I found that it exists, I would _not_
have thought of that idea.

But it might work - as long as it's super ultra thin, I think.
(Plus, as with all adhesives, it will inevitably serve _other_ uses later.)

 

[Jeff Liebermann]

On Sun, 3 Feb 2019 14:52:11 -0000 (UTC), arlen holder
<arlen@arlen.com> wrote:

1. It's 'temporary' (but firm enough to stay in place);
2. It's 'sticky' (more than the Fixodent was, but far less than epoxy is);
3. It's 'viscous' (it can't _flow_ because it will cover 4 small top ports)
4. And, it adheres to glass.

I'm having a really difficult time visualizing what this sandwich
looks like and what you're trying to stick together.

Hence, for example, all _permanent_ solutions (e.g., cyanoacrylate) fail.
The Fixodent failed only because it wasn't rigid enough (i.e., not sticky).

When gluing something by the edges, across two parallel surfaces, the
key problem is to not let the glue get between the glass plates by
capillary action. Therefore, any kind of low viscosity glue, such as
a cyanoacrylate, is going to cause a problem. What you want is
something that sticks to the edges of the plates, and doesn't run. My
best guess(tm) would be clear RTV bathroom caulk. You can smear it on
the edge of the glass sandwich and still take it apart later with a
knife. There are many formulations. What you want is probably the
type that doesn't run and just sits on the surface forming a blob. An
easy test would be to smear some on a vertical surface and see if it
runs. I suspect the adhesive type might be too low a viscosity.

You might also try hot melt glue along the edge. So there's no
mistake, you're gluing the edges of the plastic, glass, whatever
sandwich, much like the original. If you are trying to glue the
parallel surfaces, that's a different story.

Note this glue does _not_ need to have anywhere near the refractive index
of glass because the LG Stylo 3 Plus has a black 1.2 centimeter frame on
both top and bottom.

I think you mean 1.2mm, not cm.

That means there's plenty of room for a "viscous" sticky temporary glue.
The only question,. from a chemistry standpoint, is which glue is that?

I have no idea.

NOTE: I saw your other post, where I haven't delved into examining the
links yet, where again, matching the refractive index of glass isn't the
issue here as it might be with most screen reflector glues.

The other posting is on using a windshield repair kit, which uses
cyanoacrylate adhesive. I wrote that when I thought you had a cracked
glass smartphone display.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Mike]

This doesn't meet ANY of your criteria, but it worked for me.
There's clear vinyl sheet that adheres quite well to screens.
It's not glue.
You can't get it at the hardware store, but fabric stores do exist.
It's not cheaper than buying a new screen protector because it comes
in 24" or 36" widths.
I guess it does meet one of your criteria, doing it the hard way.

 

[The Real Bev]

On 02/03/2019 07:17 AM, arlen holder wrote:

On Sat, 2 Feb 2019 12:49:23 -0800 (PST), John-Del wrote:

Other than that, why not just buy a new protective screen?
They're like 3 bucks shipped and come with the adhesive already applied.

Learning about the type of glue is what this question is mostly about;
although the final repair is a secondary goal (as is the ability to repair
in the future, using the knowledge learned about the type of glue).

Given that...

There are two issues here, each of which is completely different:
1. This question is about where to obtain a specific type of "glue"
2. You seem to have fantastic sources that I am not privy to (yet).

To clarify those two completely disjoint observations...
1. Why even have a "repair" group, if all you do is "replace"?
2. You must have far better sources than Amazon given the price you quoted.

For the types of glue, I'll defer a response until I can go through Jeff's
purposefully helpful response in detail (with respect to chemistry).

The _best_ I can find on Amazon, sorted by lowest price, is:
https://www.amazon.com/s/ref=sr_st_price-asc-rank?keywords=protective+screen+lg+stylo+3+plus&sort=price-asc-rank

The cheapest, is more than twice what you quoted, although I'm sure, in
bulk, we can find cheaper (but I only need one, or maybe two, for now).

I simply ask where & how you found the protectors for 3 bucks shipped?

https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=screen+protector+lg+stylo+3+plus&rh=i%3Aaps%2Ck%3Ascreen+protector+lg+stylo+3+plus

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=screen+protector+lg+stylo+3+plus&_sacat=0


--
Cheers, Bev
Guns kill people like spoons make Rosie O'Donnell fat.

 

[arlen holder]

On Sun, 03 Feb 2019 11:10:52 -0800, Jeff Liebermann wrote:

I'm having a really difficult time visualizing what this sandwich
looks like and what you're trying to stick together.

Hi Jeff,

Thank you for understanding that the purpose of this thread is to learn how
the glue works, where to get it, how to apply it, etc., and not just how to
replace anything that is broken using a credit card as the only tool.

Since I know you to be purposefully helpful, here, as a courtesy
to you, is a picture of the exact situation of the glue itself:
<http://www.bild.me/bild.php?file=9589436plateglue01.jpg>

Thanks to your questions, I looked _closer_ at the glue
situation, where it seems I was wrong about the perimeter:
A. The glue appears to be like that on "sticky tape" where
B. The glue _is_ around the entire perimeter (which I didn't realize)
C. The glue varies from about 1mm to about 1.2 centimeters wide

Here is a measurement of the roughly ~1.2 cm bottom glue width:
<http://www.bild.me/bild.php?file=4685864plateglue04.jpg>

Here is a measurement of the roughly ~0.9cm top-glue width:
<http://www.bild.me/bild.php?file=2933568plateglue05.jpg>

Here is a measurement of the long-side ~1mm glue width:
<http://www.bild.me/bild.php?file=8035483plateglue03.jpg>

Here is a measurement of the bottom-edge 1.2cm glue width:

Notice:
A. The glue itself is like the sticky glue found on typical tape
B. There is zero glue in the center "active" area of the screen
C. But most certainly, there is 1mm of glue on the long perimeter

The situation on the plate itself is:
<http://www.bild.me/bild.php?file=1553143plateglue06.jpg>
1. The phone at right was dropped such that the plate cracked.
2. I removed that badly cracked plate easily, as 1 piece (to swap)
3. That fact pretty much proves the plate is a "plastic sandwich"

The situation I have now, is that:
4. I easily swapped the broken plate from the right to left phone.
5. It's working just fine on the left phone (no air bubbles for example).
6. It's actually _surprising_ given there is zero center-area glue

I repeat that it's actually shocking, to me, how _well_ this plate works
given that only on the perimeter has _any_ glue!

And yet, there are no bubbles.

Here's where the problem arose when we swapped plates:
7. The plate in the center was removed easily from the left phone
8. But we dropped it on the floor when moving to the right phone
9. In subsequent cleanup, we destroyed the "stickiness" of the glue

So all we need to do, really, is _exactly_ replace the missing glue.
o This question is where do we get that specific glue locally?

BTW, I think the only thing we need to do is keep it from moving.

Look at this picture which shows there is a _lip_ along the perimeter:
<http://www.bild.me/bild.php?file=5389453plateglue02.jpg>

Maybe that's why it works so well?
o All you really need to do is keep the plate next to the facescreen.

When gluing something by the edges, across two parallel surfaces, the
key problem is to not let the glue get between the glass plates by
capillary action.

I've seen the videos that use a "liquid" glue which is _not_ used here.
This is a static sticky goopy glue (sort of what's on the back of tape).

If we could figure out what glue they use to put on the back of typical
tape (like Scotch tape), that would likely be the only glue we need.

Therefore, any kind of low viscosity glue, such as
a cyanoacrylate, is going to cause a problem.

Exactly.
What's worse is a low-viscosity glue can easily cover the top ports!

What you want is
something that sticks to the edges of the plates, and doesn't run.

Yup. Exactly like the "stuff" that's on the back of "Scotch tape".
Whatever _that_ glue is, is, I think, what was originally there.

So there's no
mistake, you're gluing the edges of the plastic, glass, whatever
sandwich, much like the original. If you are trying to glue the
parallel surfaces, that's a different story.

I think we have a confusion in terms.

There are "two" sandwiches:
1. The actual plate _is_ a sandwich of glass-plastic-glass
o I know this because, even shattered, it stays firmly together.

2. Then there is the sandwich we're trying to create
o That's the original glass, plus glue on top, and then the plate.

Note that the glue was _never_ (likely) a "liquid".
o The glue is a "sticky stuff" (like that on Scotch tape) on the edges
o Specifically, the active area of the screen has _zero_ glue.
o And, the entire perimeter of the phone has a tiny "lip"

So, Jeff, two things I noticed only after you asked me to look
(Given that the plate works surprisingly well with temporary glue.)

1. There _is_ glue on the entire perimeter
(Where I had thought it was only on the top & bottom.)

2. There is a lip all around the edge of the phone
(Whch I hadn't noticed until I looked to see why it stays in place.)

There is a lip on the phone, which I never noticed until just now.
o That lip, I think, keeps the plate from sliding side to side.

All I need to do is "tack" the plate onto the glass screen.
o The original glue "tacked" the plate at the top & bottom

> I think you mean 1.2mm, not cm.

<smile>

Like you, Jeff, while I'm humble as are you, I also rarely make mistakes in
material fact, just like you rarely do.

In this case, I made an omission in material fact though, in that I hadn't
_looked_ closely at the entire perimeter until your query prompted me to
look closer at the situation.

Since my credibility is not only stellar, I want to keep it stellar, I
doublechecked my estimates on the width where, with a rule, they came to
roughly 1.2cm and 0.9 cm upon closer inspection at the bottom and top
respectively, and, unbeknownst to me until you prompted me to look, there's
also about 1mm along the long sides (that I was previously unaware of).

Like you, Jeff, I'm a rare breed who has stunningly stellar credibility.
o And, like you, Jeff, I enjoy learning from others (and on my own).

That means there's plenty of room for a "viscous" sticky temporary glue.
The only question,. from a chemistry standpoint, is which glue is that?

I have no idea.

I _think_, upon closer inspection, it's likely the _same_ (or similar)
stuff that is on the typical sticky-tape we use every day (e.g., Scotch
tape).

The question becomes:
o Where does one get the sticky glue that is on typical tape?

The other posting is on using a windshield repair kit, which uses
cyanoacrylate adhesive. I wrote that when I thought you had a cracked
glass smartphone display.

Thanks, Jeff,
You've always been purposefully helpful - and informative.

Like you, I try to always provide well-cited facts and new ideas.

In this case, I don't think a "liquid" glue is the right prescription.
THe "fixodent" would have been perfect - had it been a bit more rigid.

The _perfect_ glue, it seems, would be whatever "sticky stuff" they put on
typical tapes such as duct tape.

 

[arlen holder]

On Sun, 3 Feb 2019 11:31:47 -0800, The Real Bev wrote:

The _best_ I can find on Amazon, sorted by lowest price, is:
https://www.amazon.com/s/ref=sr_st_price-asc-rank?keywords=protective+screen+lg+stylo+3+plus&sort=price-asc-rank

The cheapest, is more than twice what you quoted, although I'm sure, in
bulk, we can find cheaper (but I only need one, or maybe two, for now).

I simply ask where & how you found the protectors for 3 bucks shipped?

https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=screen+protector+lg+stylo+3+plus&rh=i%3Aaps%2Ck%3Ascreen+protector+lg+stylo+3+plus

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=screen+protector+lg+stylo+3+plus&_sacat=0

Hi The Real Bev,

*My main clarifying point is that this question is about "glue" (not glass).*

I'm not sure _how_ to respond to your post other than to thank you for, at
least, for trying (although I don't think you realize what you posted is
not only no better than what I posted, but also worse).

We know each other well where you're generally helpful.
o But those links didn't show anything useful - unfortunately.
(Maybe I missed something obvious?)

Looking at the John-Del post, the condescending implication is
o The things are dirt cheap (where he got his numbers wrong, apparently)

But the price of the things isn't even the _question_ here:
o The question is about glue itself - the chemistry - the availability, etc.

The question _never_ was about the glass plate itself (nor its price):
o Besides, John-Del's prices appeared to be off by a *lot* (percentage wise)

So his conclusions are likewise, similarly suspect.

AFAICT, you just quoted what appeared to be the _same_ prices I found:
o At least for your Amazon link (which seemed no different than mine in quality)

For one, I've never once purchased from Ebay (and I hope I never do)
o But even so, the Ebay link was in "SEK" denomination (whatever that is)

The other link is Amazon (where I'm looking for a box store solution)
o But even so, the price you found are exactly what I found already

Hence, your post doesn't seem to add _any_ value over what I already said.
o But it's not a big deal ... it's just a question of why you posted it.

It's also not a big deal actually that "John-Del" was wrong.
o His implication was completely off base from the topic of this thread
o And his math was off by a huge amount (percentage wise)
o So his conclusions are also completely dead wrong (as a result)

Again, it's _not_ a big deal that John-Del is apparently dead wrong.
o His solution merely uses a credit card - which isn't the point here.

Yes, his solution is wrong even when it does use a credit card...
o But that isn't the point - since the point is to LEARN about the glue

Specifically, the question is merely the interesting question of:
o What kind of sticky glue did they use on this cover plate?
<http://www.bild.me/bild.php?file=9589436plateglue01.jpg>
And ... how can we get that same glue in local hardware stores?

No big deal.
o My main clarifying point is that this question is about "glue" (not glass).

 

[Jeff Liebermann]

On Sun, 3 Feb 2019 20:39:20 -0000 (UTC), arlen holder
<arlen@arlen.com> wrote:

> <http://www.bild.me/bild.php?file=9589436plateglue01.jpg>

Thanks. Now I understand. The suggestions of using double sided tape
is closest to the solution. Usually, there's a die cut pre-form in
the shape of the bezel on the phone supplied with the replacement
touch screen. It's basically double sided tape cut to the exact shape
needed to attach the digitizer. As mentioned, the backing tape is
quite thin. I couldn't find one for your LG phone.

So, that leaves the question of what manner of glue was used on the
die cut pre-form. My original guess was some manner of rubber cement.
The problem is that there are a fairly large number of different types
of rubber cement, ranging from very permanent contact cement, to the
thin temporary rubber cement sold in art supply stores for photo and
picture mounts. Kinda like the weird glue used on Post-It notes.

I have some of the die cut pre-forms for an Apple 3G which I can use
to analyze the glue. However, I don't want to, don't have the time,
and would rather be doing something more interesting. Sorry.

Meanwhile, see if the glues are acceptable:
<https://www.ebay.com/itm/9-15-25-50ML-B-7000-Strength-Glue-Phone-Screen-Rhinestone-Pasting-Adhesive/312448029236>
<https://www.ebay.com/itm/Mobile-Phone-Screen-Adhesive-Clear-Black-Liquid-Glue-B7000-T7000-E8000-T8000/232887790775>
Tape:
<https://www.ebay.com/itm/2-3-5mm-Double-Sided-Adhesive-Tape-for-Mobile-Phone-Touch-Screen-Repair-25M/302902142611>
More:
<https://www.ebay.com/sch/i.html?_nkw=mobile+phone+screen+adhesive>
It looks to be about 75% solvent, which I think is about right for a
low viscosity glue.

Notice:
A. The glue itself is like the sticky glue found on typical tape
B. There is zero glue in the center "active" area of the screen
C. But most certainly, there is 1mm of glue on the long perimeter

Again, think heavily diluted rubber cement and die cut pre-forms.

The situation on the plate itself is:
http://www.bild.me/bild.php?file=1553143plateglue06.jpg
1. The phone at right was dropped such that the plate cracked.
2. I removed that badly cracked plate easily, as 1 piece (to swap)
3. That fact pretty much proves the plate is a "plastic sandwich"

The situation I have now, is that:
4. I easily swapped the broken plate from the right to left phone.
5. It's working just fine on the left phone (no air bubbles for example).
6. It's actually _surprising_ given there is zero center-area glue

I repeat that it's actually shocking, to me, how _well_ this plate works
given that only on the perimeter has _any_ glue!

That's because the various layers of the sandwich are VERY flat and
are held together by surface tension from water vapor in the boundary
area. It's something like what holds gauge blocks together, except
those usually have a layer of oil in addition to water vapor.

>And yet, there are no bubbles.

Yep. The glass and plastic are not sufficiently elastic and will
therefore not stretch sufficiently to create bubbles.

Here's where the problem arose when we swapped plates:
7. The plate in the center was removed easily from the left phone
8. But we dropped it on the floor when moving to the right phone
9. In subsequent cleanup, we destroyed the "stickiness" of the glue

Cleaning off the old glue, and replacing it with new glue will
probably be beyond our capabilities. You can try using a rubber
squeegee to apply a thin layer, but I suspect you'll need some kind of
fixture to get any manner of consistency. It's also not worth the
effort as a new screen will do the job for less money and effort. Try
some solvent (not sure what type) on the existing mess and see if the
stickiness returns.

I've seen the videos that use a "liquid" glue which is _not_ used here.
This is a static sticky goopy glue (sort of what's on the back of tape).

When the carrier solvent evaporates, what's left is your sticky goopy
glue.

If we could figure out what glue they use to put on the back of typical
tape (like Scotch tape), that would likely be the only glue we need.

It's called a PSA (pressure sensitive adhesive) and is probably an
acrylic (or acrylate):
<https://www.can-dotape.com/adhesive-tape-consultant/adhesives-used-for-tape/>

"Scotch Transparent Tape"
<https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/scotchtape.html>
Rubber shortages during the war prompted 3M to switch to
synthetic acrylate adhesives. Although not as strong,
acrylate adhesives retained their clarity and actually
aged better than rubber-based adhesives, which turned
yellow and brittle over time. Later, acrylate adhesives
would be mated with an acetate backing to create "invisible"
ScotchŽ Magic™ Tape, the first tape that could be written
on with pencil, pen, or marker.

Basically, it's acrylic plastic dissolved in some type of solvent.

1. There _is_ glue on the entire perimeter
(Where I had thought it was only on the top & bottom.)

Ok, if there is glue all over the screen, then it has to be very thin,
not very sticky, achromatic (so the colors don't change), and very
very very clear. That's not something you'll find at the local
hardware store.

2. There is a lip all around the edge of the phone
(Whch I hadn't noticed until I looked to see why it stays in place.)

There is a lip on the phone, which I never noticed until just now.
o That lip, I think, keeps the plate from sliding side to side.

All I need to do is "tack" the plate onto the glass screen.
o The original glue "tacked" the plate at the top & bottom

I don't think the layers of the sandwich will slide over each other,
but they curl or slip from uneven temperatures.

The question becomes:
o Where does one get the sticky glue that is on typical tape?

First, you have to identify it. I usually start with a patent search.
Look for "pressure sensitive adhesive tape LCD".
<https://patents.google.com/?q=pressure&q=sensitive&q=adhesive+tape+LCD>

This one looks interesting:
<https://patents.google.com/patent/US20040191509A1/en?q=pressure&q=sensitive&q=adhesive+tape+LCD>
...examples of which include known or usual pressure-sensitive
adhesives such as acrylic pressure-sensitive adhesives,
silicone based pressure-sensitive adhesives, polyester
based pressure-sensitive adhesives, rubber based
pressure-sensitive adhesives, and polyurethane based
pressure-sensitive adhesives. The pressure-sensitive adhesive
can be used singly or in admixture of two or more thereof.
So, it can be acrylic, silicone, rubber, polyurethane, or a mixture of
the aforementioned. Not very helpful, but at least it's a start.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Jeff Liebermann]

On Sun, 03 Feb 2019 14:54:48 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:

I have some of the die cut pre-forms for an Apple 3G which I can use
to analyze the glue. However, I don't want to, don't have the time,
and would rather be doing something more interesting. Sorry.

The die cut pre-forms for the iPhone 3G
<https://www.ebay.com/itm/281081951611>
turned out to be 3M 300LSE double coated sticky tape. It's designed
for attaching digitizers to phones and high strength acrylic glue. LSE
means "low surface energy" which is a property of the material the
tape is bonding, not the adhesive. 300LSE is the 3M designation for
the adhesive, not the tape.

Google finds quite a bit on this tape:
<https://www.google.com/search?q=3m+300LSE>

Data (so many too choose from):
<https://www.hstmaterials.com/wp-content/uploads/2015/05/3M-300lse.pdf>
<https://multimedia.3m.com/mws/media/545361O/high-stength-dc-tape-w-adhesive-300lse-9475le-9475leb.pdf>
<https://www.3m.com/3M/en_US/company-us/all-3m-products/~/All-3M-Products/Adhesives-Tapes/Industrial-Adhesives-and-Tapes/Adhesive-Transfer-Tapes-Double-Coated-Tapes/Adhesive-Transfer-Tapes/?N=5002385+8710676+8710815+8710955+8711017+8713612+3294857497&rt=r3>

You can buy it by the sheet or roll:
<https://www.amazon.com/300lse-Adhesive-Transfer-Attaching-Digitizers/dp/B00LWFO5R6>
<https://www.ebay.com/sch/i.html?_nkw=300LSE>

There's also quite a bit under 3M acrylic adhesive:
<https://www.google.com/search?q=3m+acrylic+adhesive>

However, there's a problem. I don't know exactly which of the many
types of tapes that use 300LSE is best for holding smartphone screens
together. Probably the one with the thinnest backing. However, you
want a temporary bond, which makes the high strength characteristics a
rather bad idea.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[John-Del]

On Sunday, February 3, 2019 at 4:01:22 PM UTC-5, arlen holder wrote:

Looking at the John-Del post, the condescending implication is
o The things are dirt cheap (where he got his numbers wrong, apparently)

Do you even know what condescending means?

The question _never_ was about the glass plate itself (nor its price):
o Besides, John-Del's prices appeared to be off by a *lot* (percentage wise)

So his conclusions are likewise, similarly suspect.

That's two.

It's also not a big deal actually that "John-Del" was wrong.
o His implication was completely off base from the topic of this thread
o And his math was off by a huge amount (percentage wise)
o So his conclusions are also completely dead wrong (as a result)

That's three.

Again, it's _not_ a big deal that John-Del is apparently dead wrong.
o His solution merely uses a credit card - which isn't the point here.

That's four.

Wow, did I piss in your Corn Flakes sometime on another thread?

My first piece of advice to you was to contact 3M. I wasn't being flip when I suggested that no one knows more about adhesives than 3M. If you want to learn what type of adhesive was used, there's an excellent chance 3M has a product. But it won't be cheap. 3M stuff is always expensive, but it always is at the top of products available to industry and home use.


My second piece of advice was to just replace the protector. If you asked only about the adhesive for curiosity's sake, I wouldn't have said anything beyond the 3M recommendation. But since you mentioned a particular LG phone, my second suggestion was to just replace the protector which comes with adhesive and costs like 3 dollars U.S. shipped. You went out of your way to not only tell me I was wrong about the cost, but do it several times (condescending a bit?). So I did a quick check to see how far off my guess was.

I was indeed incorrect... they're more like $1.25 in a two pack shipped:

https://www.ebay.com/itm/2-Pack-Tempered-Glass-Screen-Protector-For-LG-Stylo-3-Stylo-3-Plus-Stylus-3/391861046307?hash=item5b3cbd0c23:g:ddQAAOSw66pZjLoU:rk:3f:0

You said you needed probably two, so at a buck and a quarter each, this solution is far cheaper than buying any kind of adhesive.

Yes, knowledge is great but when we're talking pennies, it just reaches the point of absurdity. If you're that hard up I'll paypal the $3.50 to you.

 

[Fox's Mercantile]

On 2/4/19 7:00 AM, John-Del wrote:

Yes, knowledge is great but when we're talking pennies,
it just reaches the point of absurdity.
If you're that hard up I'll paypal the $3.50 to you.

Arlen is the one that pots under a variety of names.
Usually cross posting to a variety of groups, on some
long rambling bullshit rant.
He doesn't want answers, he just wants to listen to himself
talk.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

 

[pfjw@aol.com]

I do not understand why the troll (holder) gets any traction at all, much less an entire thread dedicated to something as absurd as the adhesive (NOT glue) used to secure a protective sheet on phone glass. This is not the first wild hare it has sent this group a-chasing.

Just don't feed the troll. At all.

Peter Wieck
Melrose Park.